ayup Posted December 28, 2007 Report Share Posted December 28, 2007 Hallo, We bought this spiffy new 2k3 server and popped retrospect onto it, hooked our tape drive up and thought we'd be all set. Only... Looking at Wednesday's log, for example, I see that it took 17 hours to transfer 160GB of snapshots to tape. Now... We have 800GB tapes. If we ever get to where we're even using half of our available tape space then our backups will take more than a day. Heck, I'm having to clean my tape drive every day. Dang. Given that the drive is an LTO3... I should be able to have my whole backup done in under an hour. Any suggestions on how to make that happen? Thx. Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted December 28, 2007 Report Share Posted December 28, 2007 I quote rhwalker. Please provide: (1) complete version number of Retrospect (2) complete version number of Retrospect Driver Update (3) complete version number of the OS (4) complete description of hardware being used. (5) complete description of the steps you are doing (6) complete description of the problem Then my own questions: How many files are being backed up? Millions? Or just a few hundred? Have you turned off the tape drive in Windows Driver manager? If you have a tape loader, you should turn that off, too. Quote Link to comment Share on other sites More sharing options...
ayup Posted December 28, 2007 Author Report Share Posted December 28, 2007 (1) Retropsect Single Server Version 7.5.387 (the problem has always existed regardless of version) (2) Driver Update and Hot Fix, version 7.5.13.100 (3) Microsoft Windows Server 2003 R2 Standard Edition Service Pack 2. (This is not the domain controller.) (4) Dell Server PE2950, dual quad core Xeon E5335@ 2.00 GHz, 4 GB RAM, Adaptec SCSI Card 39160 (Ultra 160 SCSI), IBM Ultrium-TD3 SCSI (LTO-3) tape drive (attached to the card), Dell PERC 5/i SCSI Disk Device (RAID array with 4TB of storage). Dual gigabit ethernet. (5) Running a script that transfers all recent snapshots from 4 sources (all stored on the local array) to a tape selecting all files except cache files with options media verification, software data compression and automatically transfer any needed intermediate database Snapshots. (6) It takes about 16 hours to transfer 160GB of data to the tape drive. It's a wicked fast machine. All of the snapshots are stored on its disk array. The machine never sees 10% CPU usage. Network usage goes up to maybe 10% on only one of the gigabit ethernet lines (there's not enough traffic to warrant load sharing). Thoughts, suggestions, etc, appreciated! Edit... Watching it transfer right now. It's claiming 400MB/min. That should be something like 24GB/hr or only 6 hours for this whole job, no? Which is below the tape drive specs of 80MB/s. SCSI specs at 160MB/s, so that shouldn't be the problem... Edit2... Even then... Why only 400MB/min? It's only using 12% CPU and 100MB of RAM... It is generating 100-500 page faults a second... Hmm... Quote Link to comment Share on other sites More sharing options...
ayup Posted December 28, 2007 Author Report Share Posted December 28, 2007 Oh, right, the other questions. Sigh. How many files? Lots? About 20 people worth of files. Um. Around 500k files. I don't see the tape drive with device manager, no. Moment! Well, it's there. It's under "Other devices". From the way you're asking your question... It seems that you don't think it should be there. No tape loader other than me and I'd rather not be turned off, thank you! Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted December 28, 2007 Report Share Posted December 28, 2007 Well, the tape drive should be in the device manager, but it should be disabled (so it get's a red cross on top). What is the speed for backing up a local drive? (That avoids the LAN). What is the speed for backing up to a "File Backup Set" on a hard drive? (That avoids the tape station). Usually, performance drops (or worse) are caused by bad drivers. Have you updated the tape drive firmware and the SCSI-card firmware? And what about the NIC drivers? And anything else? Quote Link to comment Share on other sites More sharing options...
ayup Posted December 28, 2007 Author Report Share Posted December 28, 2007 Disabled - in the middle of my monthly backup Which appears to be continuing just fine so I'm going to go out on a limb and say that it wasn't using that driver! Backup of a local drive? To a backup set? It claims to backup its system drive at 863MB/min and the other server (over the LAN) at 847MB/min. Is this what you're talking about in terms of writing to a file backup set? I haven't updated the card or drive firmware but can do so... And thanks for the reply! Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted December 28, 2007 Report Share Posted December 28, 2007 When you are doing a "Backup" (as opposed to a "Duplicate"), the destination is always a "Backup Set". There are three types of backup sets: File Backup Set Disk Backup Set Tape Backup Set When backing up to tape, you use a Tape Backup Set. There are two tests you should do to narrow down the cause of your problem. 1) Backup a local drive to a "Tape Backup Set". 2) Backup your network clients to a "File Backup Set", where the backup set should reside on a local drive. What was the source and what was the destination for the 863MB/min and 874MB/min backups, respectively? Quote Link to comment Share on other sites More sharing options...
ayup Posted December 28, 2007 Author Report Share Posted December 28, 2007 Thanks for the thoughts - I'm heading out the door on vacation but will surely get back to you when I get back! c Quote Link to comment Share on other sites More sharing options...
ayup Posted January 7, 2008 Author Report Share Posted January 7, 2008 We back computers up to disk backup sets. We have 4 of those. We have many more tape backup sets. There are 2 weekly sets - Monday through Friday for set A and set B. And monthly backups. Our scripts for the tape backup sets have the disk backup sets as source files and tape backup sets as destinations (ie Monday Tape Set A for tonight). Disk backups, even over the LAN, are much faster than tape backups. I have one here that shows that my servers (OS) group got backed up at 1185 MB/min. That backup took place over the LAN. The backup of my own machine, for comparison sake, went at 141 MB/min (of course, it's understandable that it took longer - I'm farther from the server. Um. That was a joke.). I would just like to know... Why it's so darned slow to transfer to tape. From established backup sets. I mean... How hard is it? It should be faster than transfering data over the LAN! No? Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted January 7, 2008 Report Share Posted January 7, 2008 Quote: I would just like to know... Why it's so darned slow to transfer to tape. From established backup sets. I mean... How hard is it? It should be faster than transfering data over the LAN! No? Yes, the tape drive is much faster than the LAN. That is exactly the problem. The LAN can't provide data fast enough. So when a chunk of data is written to the tape, the tape has to be stopped (due to lack of data) and reversed a little. When enough data has arrived, a new chunk of data is written to the tape, the tape has to be stopped... Quote Link to comment Share on other sites More sharing options...
ayup Posted January 7, 2008 Author Report Share Posted January 7, 2008 OK, but these disk backup sets (the ones that are going to the tape backup sets) are all stored on the local server - the one with the tape drive. I'm saying that it's too slow going from its own drives to its own tape. Arg! If you have any ideas on things I can check... Thx, c Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted January 7, 2008 Report Share Posted January 7, 2008 Quote: OK, but these disk backup sets (the ones that are going to the tape backup sets) are all stored on the local server - the one with the tape drive. You didn't say that before. Quote: If you have any ideas on things I can check... There are a few unanswered questions in the thread. For instance: How many files are you backing up and how much data? (Many small files are MUCH slower than a few large files to back up.) Quote Link to comment Share on other sites More sharing options...
rhwalker Posted January 7, 2008 Report Share Posted January 7, 2008 Are the disk drives on a different I/O channel / controller than the tape drive? Are the disk drives on a different I/O channel / controller than the OS volume and swap volume? Do you have oodles and oodles of RAM for I/O buffers? It's hard to get all that data pumping in parallel. Need independent channels and lots of buffers. And LTO3 can be VERY fast, hard to keep the pipeline filled. Quote Link to comment Share on other sites More sharing options...
ayup Posted January 8, 2008 Author Report Share Posted January 8, 2008 I answered that question in my mind - are you sure I didn't do it in bits and bytes? It looks like we're putting around 500,000 files to tape. It doesn't seem to me that this is a large number of files. And, wow, they should maybe work on speed, then, no? 'Cause there are more and more files all of the time, no? Quote Link to comment Share on other sites More sharing options...
Lennart_T Posted January 8, 2008 Report Share Posted January 8, 2008 Quote: It looks like we're putting around 500,000 files to tape. 1 byte each? 1kB each? 1MB each? 1GB each? Quote Link to comment Share on other sites More sharing options...
ayup Posted January 8, 2008 Author Report Share Posted January 8, 2008 All of the hard drives are on the PERC5i backplane. The tape drive is on a SCSI 160 card. The disk storage, programs and OS are all on the same set of disks. The machine has 4GB of RAM and never uses more than ~2.5 of that. Backing up the local machine to disk on the local machine is fast. Backing up on the local machine from disk backup to tape backup is slow. Quote Link to comment Share on other sites More sharing options...
ayup Posted January 8, 2008 Author Report Share Posted January 8, 2008 Random files of random sizes. Every file from every computer on site. So a lot of little files. A lot of medium files. A small number of really big files. The backup set with the most files says 300k files for 47GB. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.