This chapter discusses the system fault-tolerant capabilities of NetWare 4.x. System fault tolerance is important for preserving the integrity of data. NetWare 4.x also provides support for UPS and the native backup services. NetWare 4.x backup uses the Storage Management Services (SMS), a hardware- and software-independent method for performing backups.
This chapter also discusses the different types of backup strategies such as full backup, differential backup, and incremental backup. The principal tool for performing backups in NetWare 4.x is SBACKUP. Use of this tool is discussed at length.
NetWare 4.x System Fault Tolerance (SFT) keeps data and software in a reliable state. This reliability is maintained dynamically while the system is up and running. NetWare 4.x provides three levels of fault tolerance:
System Fault Tolerance Level I provides data reliability by implementing the following:
SFT Level I implements read-after-write verification and hot fix (see fig. 9.1). When a block is written in any version of NetWare, it is immediately read to verify that the block that was read is the same as that which was written. This verification works by comparing the block read after it was written, giving it the name read-after-write verify. If the two blocks are different, the area on the disk is bad, and the block is rewritten into a special area called the redirection area or the hot fix area. About 2 percent of the disk (by default) is reserved as redirection area. The bad spot on the disk is recorded in a bad block table. The process of writing the bad block to the redirection area and marking the original bad block location in the bad block table is called hot fix. The bad block area of the disk never is written into until the disk is formatted and prepared again for server installation using the Surface Analysis option in INSTALL.NLM.
Figure 9.1 Read-after-write verify and hot fix.
On large disks, 2 percent represents a great deal of disk space, so you might want to reduce the percentage of redirection area.
The File Allocation Table (FAT) and the Directory Entry Table (DET) are two critical data structures of the NetWare File System (see fig. 9.2). The FAT contains the location of the data blocks on the server disk, and the DET contains the directory of files in a volume. When the NetWare 4.x server is started, the FAT and DET stored on the server volume are loaded into memory: the entire FAT is cached, and needed portions of the DET also are cached. Because loss of FAT or DET can result in loss of access to data, the FAT and DET are duplicated in separate areas of the server disk. If one of the copies of FAT or DET is corrupted, it can be restored from the second copy.
Figure 9.2 Duplicate FATs and DETs.
NetWare 4.x servers implement the Transaction Tracking System (TTS) feature for critical data operations. TTS (see fig. 9.3) enables you to back out incomplete file operations in the event of a crash. You can implement TTS on a file by flagging the file with a Transaction attribute using the FLAG command. TTS uses Novell's Btrieve database engine. Btrieve enables you to encapsulate transactions by the Begin Transaction and End Transaction operations. If the operations defined in the transaction cannot be completed, the entire transaction can be rolled back to the Begin Transaction point.
Figure 9.3 The Transaction Tracking System (TTS).
SFT Level II has two options. The first option is disk mirroring. Most ISA disk controllers support two disk channels. Disks of the same size are attached to the disk controller. One of the NetWare partitions is designated as the primary partition and a NetWare partition on another disk is designated as the secondary partition (see fig. 9.4). The secondary partition acts as a mirror image of the primary. When a block is written, it is written to both partitions. When a block is read, the read command is issued to both partitions. The disk read response that is the fastest is the one used. If disks with different sizes are used for mirroring, make the mirrored partitions on the disk the same size.
Figure 9.4 SFT Level II disk mirroring.
If the primary disk fails, control is transferred to the secondary disk. When the primary disk is repaired, the secondary disk information is transferred to the primary disk. If the disk controller fails, having a secondary disk attached to the same controller is not useful. Disk duplexing (see fig. 9.5) enables the primary and secondary disks to be attached to separate disk controllers. This feature makes the server fault tolerant toward disk controller failures. Note that SFT Level II includes the features and capabilities of SFT Level I.
Figure 9.5 SFT Level II disk duplexing.
SFT Level III enables a second server to act as a backup for a primary server if two servers are connected by a high-speed bus (see fig. 9.6). If the primary server fails, the secondary server takes over. SFT Level III includes SFT Level II.
Figure 9.6 SFT Level III server duplexing.
You can use Uninterrupted Power Supply (UPS) to provide a regulated power supply and minimize the impact of power failures (see fig. 9.7). UPS guards against data loss at both the workstation and the server by keeping them up in case of power failure. The power is supplied to the server or workstations through the UPS device, even under normal circumstances with no power failures. The UPS device provides a well-regulated power supply. If the main power line fails, the UPS is capable of continuing to supply this power while its batteries last. If the main power supply fails, the UPS sends a signal to the server that power failure has occurred. The UPS.NLM, which must be loaded at the server, receives the signal and is capable of performing an immediate shutdown of the server or waiting for a certain time before initiating a shutdown. Many UPS devices are capable of sending a separate signal when the UPS battery is depleted, and this capability can be used to initiate server shutdown.
Figure 9.7 UPS monitoring.
In NetWare 4.x, backup services are consolidated in SBACKUP.NLM. Because SBACKUP is an NLM, it can run only on a NetWare server. The server on which the SBACKUP.NLM runs should have a backup device. This server is called the host server. The data source that is to be backed up and restored is called the target. The target data can be file systems or databases on network nodes such as NetWare 3.x or 4.x, or DOS or OS/2 workstations (see fig. 9.8).
STUDY NOTE: NetWare 4.x backup services are consolidated in SBACKUP.NLM.
Figure 9.8 SBACKUP host and target machines. You can use many backup strategies with NetWare 4.x. These strategies include the following:
STUDY NOTE: SBACKUP supports full backup, incremental backup, differential backup, and custom backup.
In full backup, all data is backed up, including all diretories and files on a volume, or all volumes on a file server. After the data is backed up, the archive bit is cleared for all backed up files.
The archive bit indicates whether the data should be backed up. When a file is modified, the archive bit is set indicating that the file is a candidate for backup. Backup programs clear the archive bit to indicate that backup is complete.
The full backup strategy is the most comprehensive of all backup strategies because it backs up all files regardless of whether they have been modified since the last backup. Because of the large volume of data that might need to be backed up, however, full backup is the slowest of the backup strategies.
STUDY NOTE: The following points are true about full backups:
- All data, regardless of the setting of the archive bit, is backed up.
- The archive bits of all backed up files are cleared.
- Full backup is the most comprehensive of all backup strategies.
- Full backup can be the most time-consuming of all the backup strategies.
Incremental backup backs up all files modified since the last backup (full or incremental). Files that have not been modified are not backed up. To obtain a complete record of the most up-to-date versions of the files, start with the most recent full backup and add all the incremental changes recorded in each incremental backup session. Because only modified files are backed up, the incremental backup strategy tends to be very fast. If the number of files modified between incremental backup increases, the time required for an incremental backup also increases.
After performing an incremental backup, the archive bits of the backed up files are cleared.
STUDY NOTE: The following points are true about incremental backups:
- Only modified files that have their archive bit set are backed up.
- In incremental backup, the archive bits of backed up files are cleared.
- Incremental backup usually is faster than full and differential backups.
- The incremental backup contains a sequential history of the files that have been modified.
- To restore data in incremental backup, you need the last full backup and every incremental backup after it.
Differential backup backs up all files modified since the last full backup. The archive bit is not cleared at the end of the backup, as is done in the case of full and incremental backups. This means that all files backed up in the first differential backup also are backed up in the second differential backup, together with any files modified since the first differential backup. This process continues with each differential backup, and more files can be expected to be backed up with each differential backup.
To obtain a complete record of the most up-to-date versions of the files, start with the most recent full backup and add to it the files in the most recent differential backup session.
Because the differential backup contains all files modified since the last full backup, you can restore data with just two tape backup sets: the backup set for the full backup and the backup set for the last differential backup.
If the data on one of the last differential backups is corrupted, you can fall back on the next-to-the-last differential backup. On the other hand, if any data in another differential backup tape is corrupted, it does not matter as long as the data in the most recent differential backup is good.
Because all modified files are backed up, the differential backup is the same as the incremental backup for the first backup after the full backup. After that, the size of the data that needs to be backed up tends to grow with each differential backup. If all files have been modified, the differential backup session is the same as the full backup sessions. This tends not to be the case, because most network volumes contain a mix of program and data, and program files usually are not modified.
STUDY NOTE: The following points are true about differential backups:
- The archive bits of the backed up files are not cleared.
- All files modified since the last full backup are backed up.
- You need the last full backup and the most recent differential backup to restore data in a differential backup.
- If any data in a differential backup tape not belonging to the last differential backup set is corrupted, the data still can be recovered from the last full backup and the most recent differential backup.
- If the last differential backup is bad, you can restore data only up to the next-to-the-last differential backup.
- The first differential backup is the same as incremental backup in terms of speed and the files that are backed up.
- Successive differential backups usually take longer because more files are backed up.
It is best to use either a differential backup or incremental backup strategy. Mixing these two, while theoretically possible, can lead to confusion and should therefore be avoided.
Custom backups give you complete control over what files to back up or not to back up. You can include or exclude parts of the directory structure to be backed up or select different types of data items to be backed up. Custom backup options are presented in detail in a later section in this chapter.
Custom backups are useful if you want to selectively back up a few files and directories rather than wait for a scheduled backup.
NetWare 4.x implements backup services using Storage Management Service (SMS). SMS enables data to be backed up and restored independent of the backup hardware and file system. The SMS supports a variety of backup hardware devices and can back up DOS, OS/2, Macintosh, and Unix file systems. The capability to back up different file systems is particularly important because NetWare-based networks support a heterogeneous workstation operating system environment. SMS provides support for the following workstations and data representation:
The primary tool that uses SMS is SBACKUP. SBACKUP runs as an NLM and relies on target service agents to communicate a data representation to it. The SBACKUP.NLM runs on the server that has the backup device. The SBACKUP.NLM is responsible for backup and restore operations. The NBACKUP function of earlier NetWare releases is now consolidated in SBACKUP.
The target service agents can run on NetWare servers and communicate with servers and workstations on the network. The target service agents have knowledge of different data representations. A target service agent called TSA410.NLM, for example, is used to back up/restore NetWare 4.x file systems, and the target service agent TSA311.NLM does the same for NetWare 3.x. Table 9.1 contains a list of TSAs installed with NetWare 4.x. These TSAs can be found in the SYS:SYSTEM directory.
Table 9.1 Target Service Agents
| TSA Name | Description |
| TSA311.NLM | NetWare 3.11 file system TSA. |
| TSA312.NLM | NetWare 3.12 file system TSA. |
| TSA410.NLM | NetWare 4.1 file system TSA. |
| TSA410.NLM | NetWare 4.0, 4.01, 4.02 file system TSA |
| TSA220.NLM | NetWare 2.2 file system TSA. |
| TSADOS.NLM | TSA for backing up DOS files--runs at server. |
| TSASMS.COM | TSA runs at DOS workstation to be backed up/restored. Normally kept in the C:\NWCLIENT directory of the workstation. |
| TSANDS.NLM | NetWare 4.1 TSA for backing up NDS. |
| TSA_OS2.NLM | TSA for backing up OS/2 file system. |
STUDY NOTE: The following apply to SMS:
- The primary tool that uses SMS is SBACKUP.
- SMS enables data to be backed up and restored independent of the backup hardware and file system.
- The NBACKUP function of earlier NetWare releases now is consolidated in SBACKUP.
- SMS provides support for the following workstations and data representation:
- DOS workstations
- OS/2 workstations
- Macintosh workstations (Macintosh name space)
- Unix workstations (NFS name space)
- NetWare Directory Service
- NetWare File Systems (2.2 to 4.x)
- Btrieve (SQL) databases
Besides SBACKUP.NLM and TSAs, SMS consists of a number of other support NLMs that work together to provide backup and restore operations. Figure 9.9 shows how this can be done.
SMS consists of a number of other modules, such as the Storage Management Data Requester (SMDR), that are used to pass commands between the SBACKUP and the TSAs, and device drivers that use the Storage Device Interface (SDI) to communi-cate between the SBACKUP program and the storage devices.
Figure 9.9 The SMS components.
STUDY NOTE: SBACKUP makes use of SDI and SMDR NLMs.
SBACKUP uses the SMDR to access the TSA. If the TSA is on the same server as the SBACKUP.NLM, the data source is on the same server. An example is using the TSA410.NLM on the host server to back up the host file system. Another example is using the TSA_NDS.NLM on the host to back up the NDS database on the host server.
STUDY NOTE: The Storage Management Data Requester (SMDR) passes commands between the SBACKUP and the TSAs.
The term host refers to the server that has the backup device. The term target refers to the network device (workstation or server) that has the data to be backed up or restored.
If the TSA is on a remote machine, such as a NetWare 3.x server running TSA_311.NLM, the file system on the remote machine can be backed up. It is the responsibility of the TSA to obtain the requested data and pass it on to SBACKUP through the SMDR. The TSA is the agent closest to the source data being backed up and restored. It has knowledge of the file system or data representation of the source data.
SBACKUP is capable of backing up or restoring data by communicating with the backup device through the Storage Device Interface NLM (SDI.NLM) and the backup device drivers. The Storage Device Interface detects the presence of the device and media and presents a list of devices available to the SBACKUP program. The backup operator then can select the appropriate backup device through the SBACKUP interface. The SMDR.NLM provides a high-level interface to the backup device drivers. The backup device drivers have knowledge of the backup device hardware and use commands for reading, writing, rewinding, and ejecting the storage media. The SDI.NLM, SMDR.NLM, STREAMS.NLM, CLIB.NLM, SPXS.NLM, and NWSNUT.NLM are autoloaded when SBACKUP loads.
To back up and restore workstations, a component called the Workstation Manager (WSMAN.NLM) must be loaded on the host server. WSMAN.NLM is autoloaded when TSADOS or TSA_OS2 loads. The Workstation Manager keeps an internal list of DOS TSRs (or OS/2 and Unix daemons) that have contacted it and are available for backup/restore operation.
STUDY NOTE: Please note the following facts about SBACKUP-related components:
- SBACKUP autoloads the SDI.NLM, SMDR.NLM, STREAMS.NLM, CLIB.NLM, SPXS.NLM, and NWSNUT.NLM if they are not already loaded.
- The Storage Device Interface is used to detect the presence of the device and media and presents a list of devices available to the SBACKUP program.
- To back up and restore workstations, a component called the Workstation Manager (WSMAN.NLM) must be loaded on the host server.
- WSMAN.NLM is autoloaded when TSADOS or TSA_OS2 loads.
The SBACKUP.NLM is loaded at the server. It is similar to the SBACKUP.NLM for NetWare 3.x servers but has been customized for the NetWare 4.x operating system.
To use SBACKUP, you first must load all the necessary drivers and TSAs for the target being backed up. NetWare 4.x ships with the tape drivers listed in table 9.2. The TAPEDAI.DSK can work with any tape device on a SCSI controller.
AUTHOR'S NOTE: If the TAPEDAI.DSK driver is not installed in the SYS:SYSTEM directory on the server, you can find a copy of it in the \NW410\DISKDRV directory on the NetWare 4.x CD-ROM.
PRACTICAL TIP: Contact the tape vendor to find out if it has specialized tape device drivers that work with NetWare 4.x SBACKUP. Specialized tape device drivers are optimized for speed and work more efficiently than generic device drivers. The list of drivers bundled with NetWare 4.x changes with time. Contact your Novell reseller or Novell at 1-800-NETWARE or 801-429-7000 for the most recent list of supported drivers.
Table 9.2 Backup Device Drivers
| Device Driver | Description |
| TAPEDAI.DSK | A generic ASPI-compatible tape driver for SCSI controllers. It is designed to use the Advanced SCSI Programming Interface (ASPI). ASPI is a programming interface promoted by the company Adaptec. Most SCSI drive vendors have adopted it. |
| MNS16S.NLM and MNSDAT.DSK | Device drivers for Mountain Network Solutions, Inc. SCSI controllers and tape devices. |
| PS2SCSI.DSK | Work with PS/2 SCSI controllers and IBM 2.2 GB 8mm tape devices. |
| AHA1540.DSK, AHA1640.DSK, AHA1740.DSK, ASPITRAN.DSK | Work with devices that use the Adaptec 1540, 1640, and 1740 controllers. |
STUDY NOTE: To use SBACKUP, first load all the necessary drivers and TSAs for the target being backed up.
The TAPEDAI.DSK can work with any tape device on a SCSI controller.
The following steps guide you through the basics of performing an SBACKUP.
AUTHOR'S NOTE: The actual screens presented using SBACKUP often depend on the selections you make from the SBACKUP menu for your network environment. You can select the Backup option without logging on to the Target Service first, for example. In this case, you are presented with a screen to log in to the target service first before performing the backup operation. Another example is writing labels on tapes. If you are using a new tape or completely rewriting the tape and you have not written a new label on the tape, you are given a screen to label the tape.
LOAD TAPEDAI
PRACTICAL TIP: TAPEDAI uses the ASPI interface. ASPI does not provide sharing of tape devices between competing applications. Do not load any other device that uses ASPI when using the TAPEDAI driver.
Figure 9.10 The LOAD TAPEDAI messages.
LOAD TSA410 LOAD TSANDS
Figure 9.11 The LOAD TSA410 messages.
Figure 9.12 The LOAD TSA_NDS messages.
LIST DEVICES SCAN FOR NEW DEVICES LIST DEVICES
SCAN FOR NEW DEVICES
Figure 9.13 The LIST DEVICE command before scanning for new devices.
Figure 9.14 Executing the SCAN FOR NEW DEVICES command.
PRACTICAL TIP: When you execute the SCAN FOR NEW DEVICES command, the light indicators on the backup device light up when the device is accessed. If this does not happen, check for a loose cable or incorrect hardware configuration for the tape device.
LOAD SBACKUP LIST DEVICES
Figure 9.15 The LIST DEVICE command after scanning for new devices.
PRACTICAL TIP: SBACKUP has a SIZE and BUFFERS option, as shown in the following:LOAD SBACKUP SIZE=sizeInKB BUFFERS=numberOfBuffers
The SIZE parameter is the buffer size used by SBACKUP in KB. The value ranges from 16, 32, 64, 128, or 256 KB. The default value is 64 KB.
The BUFFERS parameter is the number of buffers reserved by SBACKUP. The value can range from 2 to 10. The default value is 4.You can experiment with higher values to improve backup performance. If you do, take into account the additional memory required by SBACKUP. This could adversely affect server performance. Selecting a buffer size of 256 KB and 10 buffers, for example, requires an additional 2.56 MB of server RAM. Because NetWare 4.x does not use virtual memory, this is a real RAM requirement.
After you load SBACKUP, you can use it to perform backup and restores.
Unload SBACKUP and the support NLMs in the reverse order of their load sequence; that is, unload SBACKUP first, then the TSA NLMs, and finally the backup device drivers. An example of this unload sequence follows:
UNLOAD SBACKUP
UNLOAD TSANDS
UNLOAD TSA410
UNLOAD TAPEDAI
PRACTICAL TIP: Unload SBACKUP and the support NLMs in the reverse order of their load sequence; that is, unload SBACKUP first, then the TSA NLMs, and finally the backup device drivers.
The following steps explain how to perform a backup operation. The steps assume that all the necessary drivers have already been loaded. If you have not done this, please refer to the previous section.
LOAD SBACKUP
Figure 9.16 The SBACKUP Main Menu.
The Backup option enables you to specify a target to back up. It also asks you to specify the location of the session log, the device and media to use, and the type of backup to perform.
The Restore option enables you to specify the target to which you want to restore. It asks you to specify which data you want to restore and the location to which you want it restored. If a session log has been maintained, you can restore based on the session name. Alternatively, you can select the data directly from the tape. One reason for restoring directly from tape is that the session log file has been deleted or is corrupted. Restoring from a session log is convenient and quicker.
The Log/error File Administration option enables you to browse through the error log file created during a backup or restore session. This option provides a quick way to determine if any errors occurred during backup or restore operations.
The Storage Device Administration option enables you to choose the device and media to use for the backup or restore operation. This option is useful if you have more than one backup device. You also can use it to check the status of the media in the backup device.
The Change Target to Back Up From or Restore To option displays the names of the targets to which you are attached. You can select a target for performing an operation. When you do so, you are asked to specify a username/password for logging on to the target.
Figure 9.17 The list of devices.
Figure 9.18 Device status.
Figure 9.19 The media list.
Figure 9.20 The status of the media in the backup device.
Figure 9.21 The selected media.
Figure 9.22 The running target services.
Figure 9.23 The prompt for the user name of the target NDSTS.
Figure 9.24 The prompt for the password of the target NDSTS.
PRACTICAL TIP: If you are having a problem logging in with a user name, use the complete name. If you are logging in as user Admin in container O=ESL, for example, use the following name:.CN=Admin.O=ESLSome of the NLMs expect complete names with attribute type specifications.
Figure 9.25 Device media to be used for backup.
Figure 9.26 Location of log/error files.
Figure 9.27 Type of backup.
Figure 9.28 Backup options.
Figure 9.29 Proceed with backup options.
Figure 9.30 Scheduling a backup.
Figure 9.31 The status screen on media label.
Figure 9.32 The backup completion screen.
STUDY NOTE: The default location of the SBACKUP error log files is SYS:SYSTEM\TSA\LOG.
The following steps explain how to complete a restore operation. The steps assume that all necessary drivers have already been loaded.
LOAD SBACKUP
Figure 9.33 The media list of backup devices.
Figure 9.34 The selected media.
Figure 9.35 Running restore target services.
Figure 9.36 Prompt for the target NDSTS user name.
Figure 9.37 Prompt for the target NDSTS password.
PRACTICAL TIP: If you are having a problem logging in as a user name, use the complete name. If you are logging in as user Admin in container O=ESL, for example, use the following name:.CN=Admin.O=ESL
Figure 9.38 The session restore options.
Figure 9.39 Selecting the location of the log and error files.
Figure 9.40 A list of sessions to restore from.
PRACTICAL TIP: Keep descriptive names of the sessions so that you can identify them later.
Figure 9.41 A status message for selecting device and media.
Figure 9.42 Media and device to be used for restoring.
Figure 9.43 The restore options for NDS.
Figure 9.44 Verify the restore operation.
Figure 9.45 Restore completion.
Occasionally, you might have a corrupted session log, or the session log might have been accidentally deleted, or the session log might not exist if you are restoring to a different server. In these cases, you must perform the restore without a session log. Perform the following steps, which complement the steps outlined in the previous section.
Figure 9.46 A session description read from media and its restore options.
The example of the restore operation was given in the context of restoring an NDS database. The restore options for restoring a file system are quite different. This section discusses the restore options peculiar to restoring a file system.
When you select the Restore a Session option from the Restore Menu for restoring a file system, you are asked to select the device/media and the name of the session from which to restore. Then the restore options shown in figure 9.47 appear.
Figure 9.47 Restore options for restoring a file system.
Select Subsets of the session to be restored from the Restore Options menu to view the data items (also called data structure) available for restoring (see fig. 9.48). This option classifies data items as Major TSA or Minor TSA resources. A Major TSA resource contains data that can be backed up as a whole when selected. Examples of Major TSAs are the file server and the volume. When you select a Major TSA resource such as a volume, all directories and files within it are considered for restore operation. A Minor TSA resource is contained within a directory structure of a Major TSA resource. An example of this is the directories and files within a volume.
Figure 9.48 Selecting restore subsets.
To include an entire volume for a restore operation, select Include major TSA resources. The box shown in figure 9.49 appears. Press Insert to see a list of major TSA resources available for selection (see fig. 9.50).
Figure 9.49 The Include major TSA resources box.
Figure 9.50 Selections for Major TSA resources.
You can use the other options for excluding or including directories or files. If you want to include a specific directory for backup, select Include directories (full path) from the Choose subsets of the session to be restored menu and press Insert to add a directory name. Figure 9.51 shows that the directory SYS:SYSTEM is selected for restore operation.
Figure 9.51 Using the Include directories option.
Select How to scan the session to be restored from the Restore Options form to view options for excluding different aspects of the file system (see fig. 9.52). This option is used for searching for the type of data contained in the data sets being restored. A data set is a group of data files and directories being restored.
Figure 9.52 The How to Scan the Session to be Restored menu.
You can select data sets to exclude from the restore operation. If you want to restore a type of data from this list, select No; otherwise, select Yes. By default, all the Exclude options have a value of No, meaning that all aspects of the data set are to be scanned for the restore operation.
The Exclude option works in conjunction with the options Subsets of the session to be restored, and Overwrite. It narrows the types of data sets scanned for in the restore operation. You can use this to exclude or include any of the following:
To restore data to a different location from where it was backed up, set the Restore data to different location field to Yes. (The default value for this field is No, which means that data is restored on top of existing data.)
STUDY NOTE: While restoring files and directories, you can exclude or include any of the following:
- Extended attributes
- Directory trustees
- File trustees
- Volume restrictions
- Directory space restrictions
The example backup operation (in the section "Using SBACKUP to Perform a Backup") was given in the context of an NDS database. The backup options are different when the custom Backup Method is selected for file systems.
When you select the Custom: Only Specified Data option from the Type of Backup menu (refer to figure 9.27), the custom backup options shown in figure 9.53 appear.
Figure 9.53 Custom backup options for a file system.
Select What do you want to back up? to view the Major TSA resource that is to be backed up (see fig. 9.54). Press Ins for a choice of other Major TSAs to back up.
Figure 9.54 The What to Back Up menu.
Select Subsets of what you are backing up from the What to Back Up menu to view the data items available for backing up (see fig. 9.55). This option classifies data items as Major TSA or Minor TSA resources.
Figure 9.55 Selections for the What do you want to back up? option.
To include an entire volume for a restore operation, select Include major TSA resources from the Choose subsets of what you are backing up menu (see fig. 9.56). The box shown in figure 9.57 appears. Press Ins to view a list of major TSA resources available for selection (see fig. 9.58).
Figure 9.56 The Choose subsets of what you are backing up menu.
Figure 9.57 The Include major TSA resources box.
Figure 9.58 Major TSA resources available for backup.
Select How to scan for what you are backing up from the What to Back Up menu to view the options for excluding different aspects of the file system (see fig. 9.59). This option shows the type of data contained in the data sets for the type of target (NetWare 4.x file system, in this case) being backed up.
Figure 9.59 The How to Scan What You Are Backing Up options.
Select the data sets you want to exclude from the backup operation. If you want to back up a type of data from this list, select No; otherwise, select Yes. By default, all the Exclude options have a value of No. This means that all aspects of the data set are scanned for the backup operation. The Exclude option works with the Choose subsets of what you are backing up option. You can exclude (Yes) or include (No) any of the following:
Using SBACKUP, you can specify whether to back up files in a compressed state. The default on NetWare 4.x volumes is that compression is enabled. This default is set at the time a volume is first created as part of the server installation.
In general, you should back up compressed files in their compressed state because the backup is faster. If you back up compressed files in the compressed state, you cannot restore them to a NetWare server that does not support the NetWare 4.x compression.
It is not a good idea to run SBACKUP when file compression is occurring on the volume; this degrades the performance of SBACKUP. Both the default time for compressing newly created or modified files and scheduling a delayed backup is 12:00 a.m. Therefore, you should schedule SBACKUP several hours after volume compression begins.
You administer the SBACKUP session files by selecting Log/error File Administration from the SBACKUP main menu. Figure 9.60 shows the options available when this item is selected. Select View a Log File to see a list such as that shown in figure 9.61. Similarly, you can view an error file by selecting View an Error File. Select Set Location of Log and Error Files to specify the location of log and error files (see fig. 9.62).
Figure 9.60 The Log/error File Administration menu.
Figure 9.61 Selecting a log file to view.
Figure 9.62 Setting the location of log and error files.
Before you can use SMS, the backup operator must be able to log into NDS. To perform SBACKUP, you also need Read and File Scan rights to the file system being backed up. These rights enable the operator to read the files and scan for names of files in directories being backed up.
If you are performing an incremental or full backup, clear the archive bit at the end of the backup pass. To do this, the backup operator must have Modify rights. To back up the NDS database, you must be able to view the NDS tree structure and read the property values of the NDS object. To perform these operations, the backup operator must have Browse object trustee rights to the NDS tree, and Read property rights to All Properties. Because Browse rights are assigned to the implicit group [public], no special considerations need to be made, unless these rights are blocked by the IRF. The Read All Properties rights must be assigned to the root of the NDS subtree for which the backup operator has authority.
If the TSA at the workstation has a password set, the backup operator must have knowledge of this password.
STUDY NOTE: The following guidelines apply to SBACKUP file rights:
- The backup operator must be able to log into NDS.
- The backup operator must have Read and File Scan rights to the file system being backed up.
- If you are performing an incremental or full backup, the archive bit is cleared at the end of the backup pass. To perform this, you must have Modify rights to the files being backed up.
- To back up the NDS database, the backup operator must have Browse object trustee rights to the NDS tree, and the Read property rights to All Properties.
You can use SBACKUP to back up and restore DOS workstations. Specific drives and directories can be backed up at the workstation. To perform a backup/restore of the DOS workstation, follow these steps:
Backing up DOS workstations is covered in more detail in the second part of this book.
Keep in mind these useful caveats when performing SBACKUP:
PRACTICAL TIP: Always have an extra supply of reusable tapes on hand in case you need to back up more data than usual.
If you are preparing for passing exams, review the chapter with the following goals:
This chapter discusses the native backup service for NetWare 4.x. NetWare 4.x backup uses the Storage Management Services (SMS). The primary tool that uses SMS is SBACKUP.NLM.
You can use SBACKUP to support different types of backup strat-egies such as full backup, differential backup, and incremental backup. The advantages and disadvantages of each type of backup strategy are discussed.
The chapter explains in detail the operation of SBACKUP for backup and restoring operations.
Test questions can have a single correct answer or multiple correct answers. Where a single answer is desired, a l notation precedes the possible answers. Some questions require you to select more than one answer. These questions are indicated by the n preceding each answer. Not all questions are multiple choice. Occasionally, a question asks you to type in an answer. The answer in this case is usually a one-word answer. The answer is not case sensitive, so you can type in the answer in lower- or uppercase.
Certain questions are repeated in different ways so you can recognize them even when the wording is different. Taking practice quizzes not only tests your knowledge, it gives you confidence when you take your exam.
A. SBACKUP.NLM
B. SBACKUP.EXE
C. NBACKUP.NLM
D. NBACKUP.EXE
A. Full backup
B. Modified backup
C. Fast backup
D. Incremental backup
E. Differential backup
A. the archive bits of all files that are backed up are cleared
B. only modified files that have their archive bit set are backed up
C. the archive bits of the backed up files are not cleared
D. the archive bits of the manually selected files are not cleared
A. the archive bits of all files that are backed up are cleared
B. only modified files that have their archive bit set are backed up
C. the archive bits of the backed up files are not cleared
D. the archive bits of the manually selected files are not cleared
A. the archive bits of all files that are backed up are cleared
B. only modified files that have their archive bit set are backed up
C. the archive bits of the backed up files are not cleared
D. the archive bits of the manually selected files are not cleared
A. It takes the shortest amount of backup time.
B. It enables files to be selectively backed up.
C. It takes more time than incremental backup but less time than differential backup.
D. It takes the longest amount of backup time.
A. It takes the shortest amount of backup time.
B. It enables files to be selectively backed up.
C. It takes more time than differential backup but less time than full backup.
D. It takes the longest amount of backup time.
A. Full backup
B. Incremental
C. Differential
D. Custom
A. the last full backup
B. the last full backup and last incremental backup
C. the last full backup and first incremental backup
D. the last full backup and every incremental backup after it
A. the data cannot be recovered
B. the data can still be recovered from the last full backup and the first differential backup
C. the data can still be recovered from the last full backup
D. the data can still be recovered from the last full backup and the most recent differential backup
A. you can restore data only up to the next to the last differential backup
B. the data can still be recovered from the last full backup and the first differential backup
C. the data can still be recovered from the last full backup
D. the data can still be recovered from the last full backup and the most recent differential backup
A. include parts of the directory structure to be backed up or select different types of data items to be backed up
B. include/exclude parts of the directory structure to be backed up or select different types of data items to be backed up
C. exclude parts of the directory structure to be backed up or select different types of data items to be backed up
D. include but not exclude parts of the directory structure to be backed up
A. TSA311.NLM
B. TSA41.NLM
C. TSA410.NLM
D. TSADOS.NLM
E. TSA_DOS.NLM
F. TSANDS.NLM
G. TSA_NDS.NLM
A. TSA311.NLM
B. TSA411.NLM
C. TSA400.NLM
D. TSADOS.NLM
E. TSA_DOS.NLM
F. TSANDS.NLM
G. TSAXNDS.NLM
A. independent of the backup hardware but dependent on the file system
B. independent of the backup hardware and file system
C. independent of the file system but dependent on the backup hardware
D. in a manner independent of the operating system
A. SDI.NLM
B. DIBI.NLM
C. SMDR NLMs
D. VLMs
E. SQRDR.NLM
A. SDI.NLM
B. SMDR.NLM
C. TSA410.NLM
D. STREAMS.NLM
E. TSA_NDS.NLM
F. CLIB.NLM
G. SPXS.NLM
H. NWSNUT.NLM
A. pass commands between SBACKUP and the SDI NLM
B. pass commands between SBACKUP and the TSAs
C. pass commands between the SDI and the device driver
D. communicate with the SDR NLM
A. SDI.NLM
B. SMDR.NLM
C. TSA410.NLM
D. STREAMS.NLM
E. TSANDS.NLM
F. CLIB.NLM
G. SPXS.NLM
H. NWSNUT.NLM
A. detect the presence of the device and media and present a list of devices available to the SBACKUP program
B. communicate with the TSA
C. detect the presence of the correctly configured device driver
D. communicate with the SMDR NLM
E. communicate with the SDR NLM
A. TSA_NDS.NLM
B. TSA400.NLM
C. WSMAN.NLM
D. WS_MAN.NLM
A. TSA_DOS
B. TSA400
C. TSA_OS2
D. TSA_NDS
A. TAPEDAI.DSK
B. TAPEDISK.NLM
C. TAPEASPI.DSK
D. TAPEASPI.NLM
A. you must unload the TSA NLMs first, then the SBACKUP program, and finally the backup device drivers
B. you must unload SBACKUP first, then the backup device drivers, and finally the TSA NLMs
C. you must unload SBACKUP first, then the TSA NLMs, and finally the backup device drivers
D. you must unload device drivers first, then the TSA NLMs, and finally the SBACKUP program
A. browse through the error log file created in the backup session only
B. browse through the error log file created during a backup or restore session
C. browse through the error log file created during a backup or restore session and edit it
D. edit the error log file created during a backup or restore session
A. SYS:SYSTEM\TSA\LOG
B. SYS:PUBLIC\TSA\LOG
C. SYS:SYSTEM\SBACKUP\LOG
D. SYS:PUBLIC\SBACKUP\LOG
A. Modify right to the files being backed up
B. Access Control right to the files being backed up
C. Supervisor right to the files being backed up
D. Delete right to the files being backed up
A. data is verified by special hardware on all hard disk controllers
B. the data block written to the hard disk is read back and compared with the original
C. data blocks read are compared to previously written data
D. data is verified by error-correcting information
© Copyright, Macmillan Computer Publishing. All rights reserved.
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