When duplicating images to a PDDO storage pool, if duplication fails initially but succeeds on a later attempt, it is possible that the duplicated images will be unrestorable.
|Article:TECH199640|||||Created: 2012-11-12|||||Updated: 2014-11-04|||||Article URL http://www.symantec.com/docs/TECH199640|
A potential for data loss has been found when PDDO (PureDisk Deduplication Option) data removal runs against images where duplication failed initially, but succeeded on a later attempt. Data loss can occur on the destination PDDO storage pool due to metadata being incorrectly imported into the PureDisk metabase. The original (source) image is still restorable until it expires.
This issue can be seen when duplications fail and successfully retry to a PureDisk Deduplication Option (PDDO) storage pool (including NetBackup PureDisk Appliance 5000/5020 storage pools). These duplications can be optimized duplications or duplications as a part of Auto Image Replication.
This issue is mostly likely to occur in environments where active duplication jobs are frequently manually terminated.
This issue affects MSDP (media server deduplication pool) servers running all versions of NetBackup through 18.104.22.168 (including all versions of NetBackup 5200/5220 Appliances through 2.5) when duplicating to PDDO storage on all versions of PureDisk through 6.6.3. (This includes all versions of NetBackup PureDisk 5000/5020 Appliances through 1.4.2.)
This issue also affects duplications from PDDO to PDDO on these same PureDisk and Appliance versions.
The root cause of this issue stems from duplication retries using the same POID (path object ID).
The formal resolution for this issue (Etracks 2734856 & 2943003) is included in the following releases:
- NetBackup 7.5 Maintenance Release 4 (22.214.171.124)
- NetBackup 5200/5220 Appliance Release Update 2.5.1
- PureDisk 6.6 Release Update 4 (6.6.4)
- NetBackup 5000/5020 Appliance Release Update 126.96.36.199
These releases are now available via the Related Articles linked below.
Please note that ALL affected products in the environment must be updated for this issue to be resolved.
Symantec strongly recommends the following best practices:
1. Always perform a full DR backup prior to making any changes to your environment.
2. Always make sure that your environment is running the latest version and patch level.
3. Perform periodic "test" restores.
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Images missing from target domain that should have been replicated via SLP
PDDO Data Removal causes data loss on retried images
Article URL http://www.symantec.com/docs/TECH199640