spawn Posted March 22, 2006 Report Share Posted March 22, 2006 We have an Exabyte VXA-2 tape drive. In Retrospect 7.0, our tapes were getting the expected utilization, according to the "Members" backup set info: (uncompressed / compressed capacity) 80/160GB tapes were getting 107-125GB 40/80GB tapes were getting about 60GB In Retrospect 7.5, they are not even getting their uncompressed capacity: 80/160GB tapes are getting 70-75GB 40/80GB tapes are getting about 36GB The Backup Set configuration hasn't changed; it's still set to use Hardware compression rather than Software compression. It sure looks like there is a bug, like it is not using the hardware compression. Any thoughts? Link to comment Share on other sites More sharing options...
spawn Posted March 22, 2006 Author Report Share Posted March 22, 2006 Note that none of the backup data is encrypted - it's passworded only. Link to comment Share on other sites More sharing options...
dqueue Posted March 27, 2006 Report Share Posted March 27, 2006 Any input on this issue from EMC/Dantz? I'm most curious, because I'm at the EOL of a VXA-1 AutoPak 1x15. I would like to go with the VXA-2 1x10 since I may use my existing tape library. I am not prepared to accept another headache, though... EMC/Dantz, please advise on the status of VXA-2 drive capacity when used with Retrospect 7.5. Many thanks. Link to comment Share on other sites More sharing options...
natew Posted March 29, 2006 Report Share Posted March 29, 2006 Hi Has the backup data changed at all? What happens if you create a new backup set with hardware compression _disabled_ and then use software compression instead? Are you using the latest driver update for Retrospect 7.5? Have you updated firmware on the VXA drive? Thanks nate Link to comment Share on other sites More sharing options...
spawn Posted March 30, 2006 Author Report Share Posted March 30, 2006 Quote: Has the backup data changed at all? The tapes are used for transferring snapshots from disk backup sets. The disk backup sets had to be recataloged for 7.5 (and one of them had to be completely recreated in order to avoid grooming crashes). Other than that, no. Quote: What happens if you create a new backup set with hardware compression _disabled_ and then use software compression instead? That is hardly what we want to do, when the tape drive has hardware compression! Quote: Are you using the latest driver update for Retrospect 7.5? There was no driver update until a couple days ago! The release notes don't say anything about VXA, but I applied it anyway. Is there any reason to think it will help? Quote: Have you updated firmware on the VXA drive? That was done before we started using version 7.0; as I recall it was required in order to use the new 80/160GB tapes. Link to comment Share on other sites More sharing options...
junk97 Posted April 3, 2006 Report Share Posted April 3, 2006 Strange that no one else has brought this up. The Exabyte VXA drives are extremely popular drives (especially since the 1x10 loaders are dirt cheap compared to other options out there). Can anyone else out there confirm these results with VXA-2 drives? Spawn, if you backup the same source to clean 7.0 and 7.5 disk backup sets and then transfer to corresponding 7.0 and 7.5 VXA tape backup sets using hardware compression, is there a clear difference in capacity? Also, what is the firmware version you are using for record's sake? It'd be interesting to find out these results before crying out bug without substantial evidence to back it up. Link to comment Share on other sites More sharing options...
spawn Posted April 4, 2006 Author Report Share Posted April 4, 2006 Quote: if you backup the same source to clean 7.0 and 7.5 disk backup sets and then transfer to corresponding 7.0 and 7.5 VXA tape backup sets using hardware compression, is there a clear difference in capacity? As I understand it, 7.5 backup sets cannot be used with 7.0, so this would take several days to test. If I had to go to that much trouble, I would probably dump 7.5 - the upgrade from 7.0 has certainly caused me plenty of grief. Quote: Also, what is the firmware version you are using for record's sake? It's 2109; I see the latest is now 210D. Were some changes made to account for new firmware? Will updating to the latest resolve this? Link to comment Share on other sites More sharing options...
spawn Posted April 11, 2006 Author Report Share Posted April 11, 2006 I have updated the drive's firmware to 210D, and applied the Retrospect 7.5 driver update. However, neither of those has made any difference! Link to comment Share on other sites More sharing options...
michaeln Posted April 19, 2006 Report Share Posted April 19, 2006 Hi, Here's what is happening: Retrospect 7.5 introduced a new comparison checksum feature to allow for faster verification and to enable media verification at a later date. By Default, under Configure > Preferences > Verification - "Generate MD5 digests" is turned on. To take advantage of this feature, Retrospect must be running on a system with a fast CPU to process this MD5 checksum algorithm. However, systems with slow backups can be adversely be affected by this and see slower backups. http://kb.dantz.com/article.asp?article=8345&p=2 These slow backups are causing streaming issues while writing to your tape, thus affecting your tape capacity. If you turn off the "Generate MD5 digests" option in the Prefs, you should see this go away. I guess the big question is "What qualifies as a slow/fast system?". In general, you should be running Retrospect on a Pentium 4 system to utilize the MD5 media verification feature. I was able to reproduce the capacity problems you were seeing with a VXA-2a on a Pentium 3 733Mhz system. I was able to get the proper tape capacity when I moved the VXA-2a to a Pentium 4 3.4Ghz system. Hope this helps. Link to comment Share on other sites More sharing options...
spawn Posted April 19, 2006 Author Report Share Posted April 19, 2006 Quote: If you turn off the "Generate MD5 digests" option in the Prefs, you should see this go away. Nope, it did not. Do the backup sets have to be recataloged for this to take full effect? Quote: you should be running Retrospect on a Pentium 4 system to utilize the MD5 media verification feature. Running on dual Xeons, so that should not be an issue. Link to comment Share on other sites More sharing options...
michaeln Posted April 24, 2006 Report Share Posted April 24, 2006 You will need to run this backup to a brand new Backup Set since the MD5 digests still exist on your existing tape set. Please let us know if that makes a difference. Link to comment Share on other sites More sharing options...
spawn Posted April 24, 2006 Author Report Share Posted April 24, 2006 Quote: You will need to run this backup to a brand new Backup Set since the MD5 digests still exist on your existing tape set. It was a new tape backup set, but the snapshots are coming from a disk backup set. Do I have to recatalog the disk backup set to remove the MD5 digests? Disabling the verification (there is only MD5 verification, no other verification option exists any longer) did not help. Link to comment Share on other sites More sharing options...
spawn Posted May 10, 2006 Author Report Share Posted May 10, 2006 Didn't get an answer to my last question, so I don't know if I will get an answer to this one, either: Is there any reason to think that there is any improvement for this with the new version 7.5.4.107? It's not listed in the changes, so probably not... Link to comment Share on other sites More sharing options...
spawn Posted June 7, 2006 Author Report Share Posted June 7, 2006 We have dumped version 7.5 here, and gone back to 7.0. The tape capacities are again what they should be. Link to comment Share on other sites More sharing options...
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