Symantec Veritas NetBackup (tm) Server / Enterprise Server 5.1, 6.0 and 6.5 with WORM tape (Updated August 21, 2007)

Article:TECH34702  |  Created: 2008-01-21  |  Updated: 2010-09-07  |  Article URL http://www.symantec.com/docs/TECH34702
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Technical Solution

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Issue



Symantec Veritas NetBackup (tm) Server / Enterprise Server 5.1, 6.0 and 6.5 with WORM tape (Updated August 21, 2007)


Solution



A new tape format for WORM tape was added with the release of Veritas NetBackup (tm) 5.1 Maintenance Pack 1 (MP1) software (all further discussion in this document mentioning NetBackup 5.1 software applies only to NetBackup 5.1 MP1 and above unless otherwise noted). This format allows appending images to tape, as can be done with standard tape. This is supported on all major operating system platforms for which NetBackup software provides a media server (NetWare and Tru64 are excluded).
 
The ability to use WORM tape with NetBackup 5.1 software is turned on by a touch file named ENABLE_WORM_TAPE. NetBackup checks to see whether this file name exists in the usr/openv/netbackup/db/config/ directory. If it does, then NetBackup enables the WORM-tape-capable code.
 
With NetBackup 5.1 software, a pass-thru path is required for all tape drives if the touch file for using WORM media exists. NetBackup software must be able to query the tape drive to verify it is a WORM-capable drive and verify that the media loaded into the drive is WORM media. This can only be done via SCSI commands so a method to pass those commands to the tape drive is required. Pass-thru paths are provided by the Veritas SG driver on Solaris, the IBM tape driver on AIX, the SG driver on Linux, the STAPE driver on HP-UX and the Windows driver, as well as the Veritas tape driver (and often other vendors' tape drivers) on Windows.
 
With NetBackup 5.1 software, if the WORM tape code is enabled and media is loaded into a drive without a pass-thru path, the NetBackup "bptm" and "bplabel" processes will fail any write operation.
 
With NetBackup 6.0 and above, a pass-thru path is required for all tape drives; if a pass-thru path does not exist, the drive cannot be used by NetBackup software. The NetBackup Auto-Discovery functionality automatically creates pass-thru paths.
 
With NetBackup 6.0 and above, WORM tape usage is automatically enabled. It can be turned off by touch file named DISABLE_WORM_TAPE  in the usr/openv/netbackup/db/config/ directory. The existence of this file removes the requirement to have pass-thru paths to all tape drives. If the file exists, NetBackup will not check for WORM media and will write to WORM media with the standard tape format. This will cause append operations to WORM media to fail.

 
With NetBackup 6.0 and above, the "bplabel" command may only be used to label LTO WORM tapes. All other WORM media cannot be labeled as the label cannot be overwritten when other media is used.
 
Because data on WORM tape normally cannot be overwritten, WORM media cannot be reused once all of the images on the tape have expired. Once all images have expired, the media can be destroyed unless there is a reason to not do so.  Properly degaussed SDLT media can be reused as either WORM or normal media. Careful attention to the degaussing process is important; if a degaussed tape doesn't work, degauss it again.
 
If the WORM tape code is not enabled, NetBackup software won't bother checking for WORM media and the NetBackup "bptm" and "bplabel" processes will write to WORM media with the standard tape format.  This will cause append operations to WORM media to fail.
 
With NetBackup 5.1 software, it is not possible to detect whether a network data management protocol (NDMP)-attached, 3-way NDMP or remote NDMP tape drive is WORM-capable or contains WORM media. Therefore, the existing NetBackup tape format will be used and append operations to WORM media will fail. Do not attempt to use WORM media with NDMP policies.
 
With NetBackup 6.0 and above, WORM media can be used when doing backups using remote NDMP.
 
Tape error recovery is disabled for WORM media. NetBackup software has resume logic which will typically attempt to continue a job that has been interrupted (e.g., an interruption on the fibre), however, when using WORM media NetBackup software will fail the job instead of attempting to resume it. NetBackup software will then automatically retry the failed job. The use of checkpoint/restart for backups is recommended because files backed up prior to the last checkpoint will not need to be backed up again.
 
The table below shows the supported WORM capable drives. In addition, the minimum tested firmware version for WORM compatibility with NetBackup 5.1, 6.0, and 6.5 software are listed. Newer firmware versions are also supported.
 
To use the Quantum SDLT 600 drive with Solaris 8 requires Solaris patch 108725-16 and for use with Solaris 9 requires Solaris patch 113277-21. In addition, the following st.conf entry must be used:
 
"QUANTUM SDLT600", "QuantumSDLT", "SDLT-data";
SDLT-data =  1,0x38,0,0x19639,4,0x00,0x00,0x00,0x00,3;

 

 
 
Vendor Drive / Interface Minimum Firmware Version NetBackup 5.1 Minimum Patch Level NetBackup 6.0 Minimum Patch Level NetBackup 6.5 Minimum Patch Level
Sun StorageTek 9840A SCSI and FC R1.34.158 MP1 GA GA
Sun StorageTek 9840B SCSI and FC R1.34.358 MP1 GA GA
Sun StorageTek 9840C FC R1.34.558 MP1 GA GA
Sun StorageTek 9940B FC R1.32.427 MP1 GA GA
Sun StorageTek T10000A FC R1.25.005C MP1 GA GA
Sony S-AIT SCSI 0200 MP1 GA GA
Sony S-AIT FC 0200 MP1 GA GA
Sony AIT-2 (SDX-500V) SCSI 0101 MP1 GA GA
Sony AIT-2 (SDX-500C) SCSI 0200 MP1 GA GA
Sony AIT-3 (SDX-700V) SCSI 0100 MP1 GA GA
Sony AIT-3 (SDX-700C) SCSI 0200 MP1 GA GA
Sony AIT-4 (SDX-900V) SCSI 0103 MP1 GA GA
IBM 3592 J1A FC 04E6 MP1 GA GA
IBM TS1120 (3592 E05) FC 16C5 MP1 GA GA
IBM Ultrium 3 (3580/T800/3588) SCSI/FC 57F7 MP4 GA GA
IBM Ultrium 4 (TS2340/3580/T1600) SCSI/FC/SAS 74H4 MP4 GA GA
Quantum SDLT 600 SCSI V30 (1E1E) MP1 GA GA
Quantum SDLT 600 FC V30 (1E1E) MP1 GA GA
Quantum DLT-S4 SCSI V31 (1F1F) MP5 MP3 GA
Quantum DLT-S4 FC V13 (0D0D) MP5 MP3 GA
Quantum / Certance Ultrium 3 (Full Height/Half Height) SCSI/FC/SAS 185G MP6 MP5 GA
Hewlett-Packard Ultrium 960 (LTO-3) SCSI G27D MP2 GA GA
Hewlett-Packard Ultrium 960 (LTO-3) FC L21D MP2 GA GA
Hewlett-Packard Ultrium 1840 (LTO-4) SCSI B14D MP2 GA GA
Hewlett-Packard Ultrium 1840 (LTO-4) FC H16D MP2 GA GA

 
Note: Please check the NetBackup Tape Drive Hardware Compatibility List for the specific versions of each OS which are supported:  http://www.support.veritas.com/menu_ddProduct_NBUESVR_view_CL.htm
 
WORM TAPE POOL
 
There are two possible methods for using WORM tape with NetBackup. The default method is to use a WORM tape pool for all WORM media. The first four characters of the pool name will be compared against "WORM" to determine whether it is a WORM pool.  Media in a matching pool will be frozen if it isn't WORM media unless it is Quantum DLT/SDLT media, which has never been used or has had all its backup images expired.
 
WORM media that is not in a "WORM" pool will also be frozen.  This pool name check is DISABLED with a touch file named DISABLE_WORM_POOLCHECK in the usr/openv/netbackup/db/config/ directory.
 
This method allows a WORM-capable tape drive to backup/restore both standard and WORM media. If you're using any WORM drive other than Quantum's DLT/SDLT, and want to use a scratch pool, the scratch pool must only contain one type of media. Put the most commonly used media in the scratch pool.
 
For example, if most backup jobs use standard media, put standard media in the scratch pool. Care must be taken to insure a WORM tape pool does NOT run out of media. Otherwise, standard media will be moved from the scratch pool into the WORM pool, loaded into a WORM-capable drive, and then frozen. This process will be repeated until all standard media in the scratch pool has been frozen. This could prevent standard backups from completing due to a lack of available media.
 
If using a Quantum DLT/SDLT drive and media, all media can be put into the scratch pool. If a "WORM" pool runs out of media, a piece of media is moved from the Scratch pool into the "WORM" pool and NetBackup software will determine whether the standard piece of media is Quantum DLT/SDLT media. If it is, NetBackup software will read the tape label and verify the media is unused or all images are expired and that the media is not currently assigned to a server. Once this has been verified, NetBackup software will configure the media as WORM, and then continue with the backup job.
 
DIFFERENT DRIVE / MEDIA TYPES
 
Another method for using WORM tape with NetBackup is to assign a different drive/media type to all WORM drives/media. For example, standard drives/media could be configured as HCART and WORM drives/media could be configured as HCART2. The downside to this method is each drive can only do backups/restores with a specific type of media so optimal usage of the drives will not likely be achieved. For example, even though no WORM backups are in process, the WORM-capable drives will not be able to be used for backups with standard media. This method allows both types of media to be put in the scratch pool since NetBackup software will automatically select the proper media type for the drive type.
 
LIMITATIONS

 
  • Third-Party Copy backups are not supported with WORM media.
  • No support for WORM tape using NDMP policies with NetBackup 5.1.
  • Not supported with the NetWare media server.
  • Resume logic is not supported with WORM tape. Backups will either fail and be retried or restart from the last checkpoint if checkpoint/restart is being used.
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NOTE:

Additional information on using WORM tape with NetBackup 6.0 and above can be found in the NetBackup Media Manager System Administrator's Guides for UNIX and Windows.  Refer to the Related Documents section below for links to these guides.
 

 



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271889


Article URL http://www.symantec.com/docs/TECH34702


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