lbertacco Posted May 11, 2004 Report Share Posted May 11, 2004 Hello, I'm using retrospect 6.5 to back part of my hard disk. That is I need to back up only some directories and exclude others. Now the real backup (file copying) takes about 30minutes, then retrospect takes more than two !@#&$#)&@#@ hours to create the snapshot and than another 30minutes to compares. I'm perfectly satisifed with the 30min copying and 30min compare, but can anyone explain WHY does this thing takes 2 hours to create a snapshot that is 80% useless!!!! It's 80% useless because it's saving "state" information of ALL files but only 20% of these have been backed up. In my opinion it's totally useless to store the "state" of files that are not backedup. This information will never be used since you cannot restore the state of a file that is not going to be restored since it has not been backed up. Anyway maybe you will convince me of the contrary. So does this make any sense? Is it possible to snapshot only files actually backedup and not the whole volume? Is this another retrospect shortcoming? Link to comment Share on other sites More sharing options...
natew Posted May 11, 2004 Report Share Posted May 11, 2004 Hi There are a couple of things we need to clarify here: Snapshots take an image of the entire disk even if you only actually backed up a single file. This snapshot image is what allows you to do a full restore of your system at any point in time. The snapshot gives you the ability to restore files regardless of when they were backed up. Basically the snapshot gives you the functional equivalent of a full backup even though you only did an incremental backup. What OS are you running Retrospect on? Do you need shapshots for all of your backups or just periodically? For example you could do a full backup on Mondays with snapshots on and then turn them off the rest of the week or something like that. Thanks Nate Link to comment Share on other sites More sharing options...
lbertacco Posted May 11, 2004 Author Report Share Posted May 11, 2004 (I'm on WinXP) Ok sounds a like a good hint. Anyway can you please elaborate more on the concept "The snapshot gives you the ability to restore files regardless of when they were backed up" ? Here I'm not talking about full vs. incremental backups. I agree that during incremental backups, the snapshot should be taken for all selected files (including those that are skipped because unmodified). But if a file is completely and always EXCLUDED (through selectors) from a backup (even full backups, e.g. I exclude temp and cache files), I don't see any point at all at taking its snapshot. It won't ever be of any use, the snapshot by itself won't let you recover the file because the file is not in the backup set (and you don't want to recover it anyway - that's why you excluded it in the first place, you just don't care about these files). So the snapshot of these file is just useles, timeconsuming and resource wasting, right? Link to comment Share on other sites More sharing options...
u235 Posted May 14, 2004 Report Share Posted May 14, 2004 I too would like to see answers to these questions as I'm having the exact same experience with Retrospect 6.5 server running on Server 2k3 and 6.5 clients running on WinXP Pro and Redhat 9. I found that a 4 minute backup of 30MB of files from a machine with the snapshot option turned off turns into a 1 hour minimum disk and CPU crunchfest where the end users are unable to get any work done (and subsequently upset). Another example is a larger script containing 12 desktops took 10 hours 15 minutes to complete with snapshots on and only 54 minutes with snapshots off (amount of data backed up was very similar). So, could somebody please point out all of the pro's and con's of having the snapshot feature turned off? The obvious benefit to me is the huge decrease in backup times. Thanks! Link to comment Share on other sites More sharing options...
AmyJ Posted May 14, 2004 Report Share Posted May 14, 2004 A snapshot allows you to restore a volume or files/folders to the exact state at the time of the backup. It creates a 'picture' of the source which Retrospect will reference to do a restore. For example, if you do backups on Monday, Tuesday, Wednesday and Thursday, but started noticing computer problems on Wednesday the snapshot will allow you to restore your system to the exact state it was in on Tuesday. If we don't have a snapshot - a 'picture' of the drive - the program wouldn't be able to do a complete restore. Other programs force users to do either: 1) Full backups nightly or 2) Multiple restores just to get the computer back to the state it was in on a given day. The Retrospect snapshot technoloy allows you to perform full restores from incremental backups - and only requires one restore to get you back to where you want to be. Let's use an example of how this works: Monday: Backup My Documents with 200 files Tuesday: Backup My Documents with 10 new/changed files Other programs would require you to either do two restores to get back to that point (one from the full on Monday and a second from the differential on Tuesday), or it would require you to do a full backup each night - all 200 files. Retrospect is able to look at the snapshot and see all the files that were there on Tuesday night (even though the majority were backed up on Monday) and do a complete restore of your My Documents folder to the state it was in on Tuesday. If you choose to turn off snapshots your only restore choices would be to 'search' for files and folders with criteria such as name, size, date, etc. Link to comment Share on other sites More sharing options...
lbertacco Posted May 17, 2004 Author Report Share Posted May 17, 2004 So , suppose that I turn snapshot off (because I don't want to waste the 2+ hours it takes to snapshot files excluded from backup), I do a full backup on sunday and incremental on monday to saturday. Then I want ro restore to the last say tuesday. Usign restrospect and snapshot disabled will I be able to do : - full restore of sunday - full resotre of the monday incremental - full resotre of the tuesday incremental and get the wednesday status in this way with 3 restore (as I can do with any other backup program)? I'm asking this because your claim: "If you choose to turn off snapshots your only restore choices would be to 'search' for files and folders with criteria such as name, size, date, etc. " sounds quite worrying to me and makes this look impossible. Link to comment Share on other sites More sharing options...
lbertacco Posted May 17, 2004 Author Report Share Posted May 17, 2004 sorry for the typos ;-). Wednesday was ofcourse tuesday again, and resotre means restore. Link to comment Share on other sites More sharing options...
natew Posted May 19, 2004 Report Share Posted May 19, 2004 Hi The shapshot includes the Windows Registry and the directory structure. If you backup with snapshots off your backup set becomes a bucket of files more or less with nothing to tie them to a particular day. During a restore you could pick files by name, modify date, size etc. but you won't be able to organize them into a backup day very well. One solution would be to take snapshots on say Sunday, Wednesday and Friday and turn off snapshots for the other days. You will need to use two scripts to do this but it may be a good compromise. Nate Link to comment Share on other sites More sharing options...
u235 Posted May 20, 2004 Report Share Posted May 20, 2004 I see, well this all makes sense. It's too bad retroclient can't just grab the master file table and send it off to the server rather than digging through the machines' hdd's rendering them useless for an hour. That may not even be possible, in any case this makes things tough... Actually, having a bucket of files doesn't seem so bad when you're only backing up <10 directories. I'm assuming most folks just live with the snapshot 'feature'? Thanks everyone for the clarification though, much appreciated. -Kurt Link to comment Share on other sites More sharing options...
natew Posted May 20, 2004 Report Share Posted May 20, 2004 Hi Retrospect has used snapshots for a long time and most people do consider it a great feature. The problem we have recently is that the number of files and folders on a disk is growing so rapidly it takes a lot longer to build the shapshot than it used to. Snapshot creation time is something we are taking a close look at now. Nate Link to comment Share on other sites More sharing options...
Katie Piecrust Posted July 22, 2004 Report Share Posted July 22, 2004 Why not just do incremental snapshots instead to save time? If your hard drives state has already been recorded in a previous snapshot, then why not just use it and log the changes, as well as continue to do a full snapshot of the important stuff, like the registry for example? Seems like a logical step to me since you're already doing it with file backups. Link to comment Share on other sites More sharing options...
natew Posted July 23, 2004 Report Share Posted July 23, 2004 Hi Retrospect uses some built in Windows commands to gather the file system information used for the snapshot. At present those commands do not allow incremental scans of NTFS folder and file permissions. Its all or nothing really. This is true for all backup set types including file backup sets Nate Link to comment Share on other sites More sharing options...
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