QonoS Posted July 9, 2003 Report Share Posted July 9, 2003 Retrospect takes what seems to be an inordinately long time to create a snapshot every time I back up. The time seems independent of the size of the (incremental) backup. As a recent example/experiment, I ran an incremental backup and then almost immediately ran the same script over again. Only 20 files totaling 10 MB got backed up the second time (no surprise there). Retrospect nonetheless spent about 28 minutes creating a snapshot for this backup, and it appeared that the program went through every single file on the volume to do so. Is this normal? Is there a way it can be speeded up? Usually this is the *longest* portion of any backup I do. (When I had previously backed up 756 MB worth of files, the copy only took 19 minutes.) FWIW I also use Retrospect Express for Mac OS X, and it does *not* exhibit this behavior. My system is a 300 MHz PII laptop, running Win 2K SP3. I back up to an external USB hard drive. I use Retrospect Express v 5.15. Thanks for the help. Link to comment Share on other sites More sharing options...
AmyJ Posted July 21, 2003 Report Share Posted July 21, 2003 A snapshot is a picture of the entire source and is independent of the files actually backed up in a given session. A snapshot allows for a drive to restored back to the given state at the time of backup. In order to do this, the snapshot must include all files. Link to comment Share on other sites More sharing options...
QonoS Posted July 22, 2003 Author Report Share Posted July 22, 2003 This long delay does not happen when I back up under Mac OS X. Is the snapshot creation a Windows-only thing, or is it dramatically slower under Windows? Link to comment Share on other sites More sharing options...
AmyJ Posted July 22, 2003 Report Share Posted July 22, 2003 Retrospect for Windows must take a snapshot of the files, the NTFS permissions and the System State information. On larger volumes, this can be a lengthy process. Link to comment Share on other sites More sharing options...
QonoS Posted July 23, 2003 Author Report Share Posted July 23, 2003 Quote: AmyJ said: Retrospect for Windows must take a snapshot of the files, the NTFS permissions and the System State information. On larger volumes, this can be a lengthy process. Okay, here's a comparison of volumes and file counts. My Win 2K drive is a single partition with a total capacity of 18.6 GB. Of that, 4.23 GB is used, for about 24,500 files. My Mac OS X boot partition has a total capacity of 6 GB, with 3.8 GB used, for about 124,000 files. So my Mac OS X boot partition contains 5 times as many files as my Win 2K drive, occupying about 90% of the space (3.8 GB vs. 4.23 GB). Yet snapshot creation on an incremental backup under OS X -- if it occurs at all -- takes negligible time. Scanning the source volume does take somewhat more time, because of the large file count, but even that process -- scanning and updating of Unix permissions (which I assume have some of the same characteristics as NTFS permissions) -- takes only a little over 10 minutes. There are of course other variables, not the least of which is system speed. Nonetheless, I'm curious what's going on. 1) Does Retrospect for Mac OS X *not* create snapshots with every incremental backup? Are they unnecessary under Mac OS X but necessary under Windows? 2) If Retrospect for Mac OS X *does* create snapshots with every incremental backup, what is the source of the discrepancy in speed? I would assume that approximately the same type of information would need to be stored under either OS in order to restore a volume to the state it was in when last backed up. I realize this could be an artifact of OS differences, but I'm not clear from the discussion so far what the source of the discrepancy is. Sign me, Curious Link to comment Share on other sites More sharing options...
gerken Posted October 1, 2003 Report Share Posted October 1, 2003 I am thinking of upgrading to Retrospect 6.5. From Retrospect Express 5.6. Will I still be faced with the long snapshot process on an incremental backup? Link to comment Share on other sites More sharing options...
AmyJ Posted October 2, 2003 Report Share Posted October 2, 2003 We've made some improvements to the time it takes to create a snapshot in 6.5. 30 day trial editions are available from: http://www.dantz.com/en/products/personal.dtml Link to comment Share on other sites More sharing options...
gerken Posted October 2, 2003 Report Share Posted October 2, 2003 Thanks. One question: will 5.6 and 6.5 run side by side or will I have to uninstall 5.6 during the test? Link to comment Share on other sites More sharing options...
rtestardi Posted October 30, 2003 Report Share Posted October 30, 2003 The snapshot seems to take long if any files in the filesystem are changing... Like if they are continually changing, the snapshot might actually never complete... I now quiesce my system for the snapshot (close VPN, NAV, etc.) and it goes faster... Link to comment Share on other sites More sharing options...
jeg Posted December 7, 2003 Report Share Posted December 7, 2003 It could be the "System Restore" problem. Have a look at: http://www.dantz.com/index.php3?SCREEN=kbase&ACTION=KBASE&id=27294 Link to comment Share on other sites More sharing options...
DantzEvangelist Posted February 19, 2005 Report Share Posted February 19, 2005 We've been a Retrospect VAR (indeed have tested Retrospect from about 4.0 to 6.0 Multi-Server), and a former Evangelist of Retrospect (especially because of its cool true snapshots, and its Boolean-algebra of selectors), but because of SOME SERIOUS BASIC SCALABILITY PROBLEMS (including exhaustive snapshots mentioned in this thread) which don't seem to get fixed (_please correct me if I'm wrong_), we're thinking of scrapping Retrospect and finding & recommending something else (as possibly www.Connected.com or www.nasi.com/veritas-netbackup.php or (upcoming) www.acronis.com/enterprise/products/ATICW ). OUR LEADING PROBLEMS WITH RETROSPECT thru 6.0 MULTI-SERVER (ALL SERIOUS SCALABILITY LIMITATIONS) are: 1st, "Snapshot creation takes a [potentially extraordinary] long time" (naturally because it's NOT incremental: only changed files are backed up, yes, but ALL folders are backed up regardless) So, for just 1 notebook PC (only 33GB of data), *even if no or just a few files have changed* (the typical case each day), still takes about 4 hours if running in the background (and very disruptive), or, if idle, still takes an intense 1.5 hours; awkward for any computer (except a desktop left on & connected at night), and typically prohibitive if a common road-warrior where connectivity and bandwidth and perhaps batteries are a premium. And, even if no file was changed, each time (as each day), it also takes 124.0MB of backup storage, which, though wasteful, is okay if backing to DVDs and not CDs). 2nd, frequent errors wasting serious CD and DVD media storage (7 in 28 (1 in 4) DVDs fails to get filled (filled only about 1/2) because of premature unrecoverable aborts; plus no option to verify media as it's written, or at least before it's ejected if spanning (argued this "benefit" with the president Larry Zhulch) causing much data to not get verified (at least if you verified as you went you'd get some of it verified) and so have to be backed up again (a problem compounded by media errors and lengthy snapshots (and thus more exposure to interruption)). 3rd, since the server contacts the client, not the other way around, inability to backup clients behind common routers, NATs/connection-sharing, and firewalls (a simple problem solved by every Internet backup solution) 4th, the lack of file deltas (as entire my 700MB Outlook .pst (data file) was getting rebacked up *every day* just from each day's adding a few tiny items, or simply browsing it). Lacking file deltas (something which every leading Internet backup has), from just this one file, easily costs me 7x the time and media. So I've fortunately devised a worked around for this by creating multiple backup jobs: an every day job which backs up anything up to 10MB (roughly), an every 10 days which backs up everything up to 100MB, and every 100 days which backs up everything up to 1000MB, and an every year which backs up everything; but this fix means my (critical data) .pst file only gets backed up every 100 days! BUT AM I WRONG? HAVE ANY OF THESE GOTTEN FIXED REALLY? AND HOW? For instance, AmyJ says above "We've made some improvements to the time it takes to create a snapshot in 6.5" -- what improvements exactly (now in 7.0)? In particular, do you have incremental snapshots, only snapshotting the *folders* which have changed, the seemingly only scalable way to fix this problem? And what about the other serious issues? Thanks, -Mike Parker Small Busineess Networks and MIT CS Grad, www.Cytex.com/go/MBParker/Professional Link to comment Share on other sites More sharing options...
QonoS Posted February 20, 2005 Author Report Share Posted February 20, 2005 Quote: It could be the "System Restore" problem. Have a look at: http://www.dantz.com/index.php3?SCREEN=kbase&ACTION=KBASE&id=27294 That's an XP problem. As I mentioned in my OP, I'm running Win2K (SP4 now.) AmyJ: With all due respect, your posts have not answered the question why it's so much longer under Win than Mac OS X. Mac OS X also has file permissions, granted not the same as with NTFS, but they are there. So by itself, that does not explain the problem. Link to comment Share on other sites More sharing options...
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