| Pat Regan on 1 Nov 2005 13:51:24 -0000 |
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Edmund Goppelt wrote: > As I recall you used to work for Penn which has lots of > resources--both money and people. I'm in a different situation: it's > just me and I have to watch every penny. > You'll have to forgive me, as well. My background involves data storage and backup for relatively large companies with deep pockets, as well. However, everything I learned from working with the high end stuff translates quite well even to what I do at home. The value of the data is different, however. That changes the frequency of my backups to external media :). > I realize you may not be used to working under such constraints, but > I'd love to hear your thoughts. How do you think I should go about > backing up my 8 or so systems? > I'll reply to this part below :). >> The primary issue is -- how long is it going to take you to return >> things to the way they were "before" you lost the system? A 1-TB >> data store takes A LONG TIME to restore! > > This has not been my experience. It took me about 4 hours to do a > bare metal restore of my main web/database server recently. > I think he is referring to how long it takes to restore 1 TB. Extrapolating from what you've mentioned so far... You have 8 machines, 80 GB each. And I will assume your web/database server was equal to the other 7. Restoring all 8 machines (.64 TB) might take a full 24 hours. It might take more, it might take less. It depends whether the bottleneck at that point becomes you or the network :). I don't think the odds are high that all your machines will suffer a failure at the same time unless there is a natural disaster. I will bet that in your case, the last thing you will be worrying about is those 8 machines :). > The 1 TB refers to the storage capacity avaialable for backups. Most > of my systems use less than 80GB. > OK. I will tell you what I would do with the minimum possible budget. I would start by deciding how often you really need to back up all 80 GB. All data is not created equal. The easiest way to have a manageable backup size is to archive old data. That doesn't mean you have to move it somewhere you don't have access to it. Just make an "Archive" directory, move all your old stuff into it, back it up to tape/dvd/cd once or twice and then send it off site. This way you can easily ignore that data on daily/weekly/monthly backups. It saves both space, and usually more importantly time. My home desktop and laptop backups fit on 3 DVDs because of the data I can ignore. Once you do that, you will know how much data you have to backup. At this point I would build a backup server. Since speed is not likely an issue, I would likely buy enough drive for RAID 5 plus a hot spare (and probably a cold spare). Remember, the bigger the drives the longer it takes to rebuild after a failed drive. Since a hot spare will be there right at the moment of failure, rebuilding begins immediately. If you have a cold spare you can swap it in ASAP, then you don't have to wait for an RMA. As far as on line backup software, I am a huge fan of rdiff-backup. On my personal machines here at home I run 2 backups each day, and I keep 1-2 months of these incremental backups available. On average, 2 months takes up a total of about twice as much space as just a full backup. Your mileage may vary quite a bit, though. I setup a similar strategy for a friend of mine over a year ago. She currently has every backup right up to the first one available, and she isn't even using double the space yet. Out of your 8 machines, I would guess that some generate more new data each day than others. Once the data is on the backup server, I would highly recommend getting that data onto some removable media. On a budget, I would try to use DVDs. If you really have 640 GB of data that you actually need to backup every cycle, you are outside the range of a "cheap" backup solution. I don't know what kind of data you have, but assuming 2:1 compression (I am assuming this isn't video or images :p)... 320 gig would require almost 80 DVDs, which doesn't sound feasible to me. ebay seems to have 200/400 LTO drives selling for 500-700 dollars. At 2:1 compression your backup would fit on 2 of those tapes. If you really end up with 300+ compressed gig to back up, this would be the route to go. If you can pare the backup down to an average of under 10 GB per machine, DVDs are probably the way to go. Burners are 60 bucks, so you can buy a few of those. Media is as low as 15 cents per disc (but don't buy the cheapest :p). The biggest advantage the DVD backup gives you is restores. If you had to restore all 8 machine, you could put the backups right into the drives. I think the discussion of what kind of schedule you should use for off line backups would be better left to another message, as this one is getting quite long :). Pat Attachment:
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