dbudic Posted June 3, 2008 Report Share Posted June 3, 2008 My situation: Windows server 2003 with Retrospect 7.5.508, driver pack 7.5.14.102. Connected via gigE/iSCSI to a Spectra Logic T50 w/ LTO4 drives. Whenever I try recovering an exchange snapshot or mailbox files, Retrospect/windows attempts to recover files (and sometimes succeeds), but the library always falls off the iSCSI buss, neither retrospect nor windows sees it any more. I generally have to POR the library to get it to be useable again. Oddly enough, the tape drives usually remain connected and useable, it's just hard to change tapes when the library won't talk to you... Although they too have occasionally disappeared as well. This problem does not occur with other types of data, be it large movies from a media server, or system files from the exchange server, just the snap shots and the mailbox files. It is reliably reproducible. I've been working with support at Spectra Logic, and we're wondering if Retrospect does anything different (scsi command wise) with Exchange Backups than it does with other file based backups, or if there is anything else that we might be encountering that anyone has heard of. Any ideas what's up? Thanks! -Darrell Quote Link to comment Share on other sites More sharing options...
Mayoff Posted June 3, 2008 Report Share Posted June 3, 2008 I moved this topic. It technically is not an exchange issue. Probably the library is having trouble accessing very small files. What happens if you try to restore a 1 or 2kb file from a C drive, as an example? IE favorites are small and a good type of file to test a small restore with. Yesterday I needed to do a restore of 35 files for a total of 35k from a tape drive. It look the tape drive 55 minutes and .1 mb/min to finish this restore. Tape drives do not like to "locate" small files. You will sometimes have better performance by selecting a large number of files in the same spot of the tape, so the hardware can stream the data. If the unit falls off the computer and the iSCSI initiator/computer can not see it, then this is a hardware communication problem and not because the data comes from an exchange mailbox. Quote Link to comment Share on other sites More sharing options...
dbudic Posted June 3, 2008 Author Report Share Posted June 3, 2008 Some of my test files from that server that I was able to successfully recover were 1 and 2kb, they recovered fine, with no delays. I had posted that under Exchange because the problem only appears with Exchange Mailbox Snapshots or mailbox content recovery, and not with any "normal" file recovery attempt. The symptoms of the problem are that the host computer looses iSCSI contact with the library _WHILE_ Retrospect is attempting to read the Exchange Mailbox Snapshots or Mailboxes. It's reproducible. This is definitely a communications problem, which is why I'm working with Spectra Logic on it. It does appear to be triggered by something retrospect does while recovering exchange related files, though. In fact, I'm here hunting for answers because Spectra Logic suggested that maybe Retrospect does things differently when using the exchange connector than it does otherwise, and they'd like to know if it does for troubleshooting purposes. Heck, we're almost at the "snoop the iscsi traffic" stage, so I'd like to find any clues or ideas about what might be going on before that happens! Any ideas about what might be going on differently other than file sizes? -Darrell Quote Link to comment Share on other sites More sharing options...
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