jmboatner Posted February 21, 2008 Report Share Posted February 21, 2008 We inherited a system from another company. OS X Server 10.3.9 running on a Duel 1.25 GHz PowerPC G4 with 2 XServe RAIDS attached, Retrospect 6.0.204, Device access version 1.0.106, Driver Update 6.2.102, Sony AIT Library D81/A4. 2 problems: The first is that I don't seem to be getting much compression on my AIT-4 tapes. At most, I'm only getting 250GB on one tape. Most of the Catalogs from the previos company range from 23GB (?) to 271GB. We archive and back up digital files fro printing (page layout files, photos, vector art). The other issue is that when I go to view what's left on a particular member, it tells that 0GB is available of 0GB of capacity. Will the upgrade to 6.1 help these issues? I've read on these forums that there are issues with 6.1 and thinking that existing tapes are WORM tapes (although I don't think this tape drive has that capacity; it's the silver model, not the black one on Sony's web site). ANY help will be appreciated. Link to comment Share on other sites More sharing options...
rhwalker Posted February 21, 2008 Report Share Posted February 21, 2008 There seems to be some misinformation/confusion that you have about Retrospect 6.1. Taking the points out of order: Quote: I've read on these forums that there are issues with 6.1 and thinking that existing tapes are WORM tapes (although I don't think this tape drive has that capacity; it's the silver model, not the black one on Sony's web site). There are two issues here. One, I believe is a bug that has been fixed. The other is a feature caused by database changes in the backup structure such that, once you upgrade to Retrospect 6.1, you cannot write to backup sets made with earlier versions, but you can still read them. It's documented in the Read Me release notes for Retrospect 6.1: http://kb.dantz.com/article.asp?article=8117&p=2 Quote: The other issue is that when I go to view what's left on a particular member, it tells that 0GB is available of 0GB of capacity. This is normal. The "remaining capacity" is completely artificial and can be set to whatever you want; Retrospect will always write until it hits EOT. See the last three items at the end of: http://kb.dantz.com/article.asp?article=5658&p=2 Quote: I don't seem to be getting much compression on my AIT-4 tapes. At most, I'm only getting 250GB on one tape. See these KB articles: http://kb.dantz.com/article.asp?article=5621&p=2 http://kb.dantz.com/article.asp?article=5658&p=2 http://kb.dantz.com/article.asp?article=6284&p=2 http://kb.dantz.com/article.asp?article=5616&p=2 Your machine is a bit slow to keep the streaming drive's pipe filled, and that will diminish your capacity a bit. Also, your data is of a type that doesn't seem to lend itself to much compression. As a comparison, we've got an Exabyte VXA-2 1x10 1u PacketLoader (SCSI) attached to an ATTO UL4D in our 2 GHz Xserve G5. We see about 115 to 120 GB (compressed) on X23 tapes that are rated at 80 GB uncompressed, 160 GB compressed (artificial marketing numbers, if you ask me). You might want to try some AIT diagnostics, if you have any, to see how much compressed data they could write to a tape with big block sizes. Most of the people having issues with Retospect 6.1 are running Intel architecture and/or Leopard. We can only hope for a stable Retrospect X release that will be Universal Binary so that the Rosetta millstone can be discarded. You don't have either of these issues with your present configuration. There are some issues with some of the recent RDU versions, and, if 6.1.13.101 gives you issues, I suggest you revert to 6.1.11.101 if you don't need the latest bugs. See: http://kb.dantz.com/article.asp?article=7886&p=2 Hope this helps, and you should really consider upgrading. It's a free upgrade, and many bugs have been fixed. Russ Link to comment Share on other sites More sharing options...
jmboatner Posted February 22, 2008 Author Report Share Posted February 22, 2008 I realize the speed of the machine will affect the speed of the backups, how does it affect the capacity of the tape? I know I'll never get the full 520GB that the AIT-4 tapes advertise, but I'm barely getting more that the 200GB native capacity. I would hope to at least get between 300-400GB. I've used AIT1-2-3 drives in other shops and gotten better results with the same types of files. We've also had issues with kernal panics while Retrospect is running. This box doubles as our file server, running 2 XServe RAIDS. I may try to put the tape drive on a G5 running Tiger and see if I have better luck. Let me know what you guys think. Link to comment Share on other sites More sharing options...
rhwalker Posted February 22, 2008 Report Share Posted February 22, 2008 Quote: I realize the speed of the machine will affect the speed of the backups, how does it affect the capacity of the tape? Because that's how streaming drives work. Streaming drives need to keep their pipe full so that they can lay down successive blocks (packets with some technologies) on the tape. If the pipe is not kept full, the tape will have to "backhitch" (pass by where it wants to write the next block because it is starved, rewind, then get another running pass at the area after the last written block). This will wear out the tape, because tapes are rated by the number of passes over the head. To ensure that they can stream, streaming drives, if they are starved, will lengthen the space between blocks so that they can keep streaming and so that the tape doesn't get worn out. This increase in the inter-block spacing decreases the capacity of the tape. This is why Retrospect makes your computer unresponsive when backups are occurring. Retrospect tries hard to monopolize your computer so that it can keep the pipe filled to keep a tape drive streaming. Russ Link to comment Share on other sites More sharing options...
CallMeDave Posted February 22, 2008 Report Share Posted February 22, 2008 Quote: 2 problems: The first is... The other issue is... {snip} We've also had issues with kernal panics while Retrospect is running. There is no description as to how the AIT drive is connected to the Macintosh. Please describe your hardware more completely. Dave Link to comment Share on other sites More sharing options...
rhwalker Posted February 22, 2008 Report Share Posted February 22, 2008 Quote: I may try to put the tape drive on a G5 running Tiger and see if I have better luck. Ok, then it won't be the same test. You will have to upgrade Retrospect to 6.1.138 to run Tiger (and that upgrade will have a lot of bug fixes); you will have a different OS; you will have a different SCSI interface and driver (because new drivers are needed for MacOS 10.4.x); etc. It's almost as if you expect a miracle to occur on your existing system because you don't want to upgrade the software, hardware, etc. Something has to change if the operation is to change. Note that very few SCSI cards are supported on Tiger. It's pretty much ATTO, which works fine. Russ Link to comment Share on other sites More sharing options...
jmboatner Posted February 22, 2008 Author Report Share Posted February 22, 2008 Adaptec 29160 SCSI card. I have upgraded to 6.1, but still getting kernal panics. We almost have to move to another machine if we're going to keep having the kernal panics. We're looking into moving the host machine for our XServe RAIDS to a G5 ( we have 4 spares...) anyway. We just can't have our file server crashing every time someone does a retrieval. Link to comment Share on other sites More sharing options...
twickland Posted February 22, 2008 Report Share Posted February 22, 2008 Quote: Adaptec 29160 SCSI card. This host adapter is not certified beyond OS 10.2.8. While some people have been able to get the card to work with later system versions and certain SCSI devices, we needed to replace ours with an ATTO host adapter when we got up to around 10.3.4 (we started having kernel panics). Link to comment Share on other sites More sharing options...
jmboatner Posted February 22, 2008 Author Report Share Posted February 22, 2008 If we can't upgrade everything, at the very least we'll upgrade the card. I would imagine that would solve a lot of issues. Thanks for all the help. Link to comment Share on other sites More sharing options...
rhwalker Posted February 22, 2008 Report Share Posted February 22, 2008 JM, Here's Adaptec's notice when they abandoned the Macintosh platform and stopped developing drivers: Adaptec abandons Macintosh platform If you get another card, avoid the Apple dual-channel SCSI card like the plague; it's a piece of junk. Been there, done that. We got one as a part of our Build-to-Order Xserve G5, never worked right with Retrospect, and other backup software suppliers agree. It's really an LSI Logic 22320 dual-channel SCSI card. Drive and/or autoloader disappear after reboot sometimes and are not seen by Apple System Profiler, other issues too. Everybody has pretty much agreed that ATTO is the way to go. UL4S or UL4D on the G5, UL5D or UL5D Low Profile (Low Profile for the Xserve) on the Intel platform. When we replaced our Apple dual-channel SCSI card in our Xserve G5 with the ATTO UL4D, all of the problems disappeared. The Apple card isn't even heavy enough to use as a paperweight, just gathers dust in a cabinet. Good riddance. Russ Link to comment Share on other sites More sharing options...
jmboatner Posted February 25, 2008 Author Report Share Posted February 25, 2008 I've include the ATTO card in a request to upgrade our server to a G5. If they don't upgrade the server, then I'll get a new card for the G4. Thanks to everyone for all the help. Link to comment Share on other sites More sharing options...
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