09-26-2001
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Join Date: Sep 2001
Last Activity: 16 December 2002, 4:51 PM EST
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Hmmm....
Well-
you tried my favorite already, "dd" is great, but how about a "dd" once a month, for a "Full image" mirror, and then using a *fsdump command to dump over the slices of the fs for the rest of the month? this is faster, but not as strenuous or inclusive as "dd". Is this a heavily used server 24/7? If not, the "dd" on a nightly or weekly basis should be fine. If the data is pretty static, like some static web pages with a separate database for info storage, then I'd say that a weekly "dd", and another whenever any major revisions are made would be good, but it really comes down to the state of your data. Since you are only looking at the mirror to maintain uptime, I am assuming this is some sort of webserver. If not, I'd look at getting something off to tape as well asap, you can never have too many backups to a removable media source. I'll also go with the hardline approach on this one, buy a good tape drive if you are using one, a good way to determine the value of your data is to see how much you put into your backup system. If you backup to a $10 DDS1 DAT drive, that must be all your data is worth to you.
My old place of work used to backup our webserver like this:
-weekly "dd" to an IDENTICAL drive as that in the server itself
-nightly ufsdump of the critical filesystems over to the mirror drive
-daily tape backup to a DLT, incremental and a monthly full image
This worked on a Solaris box, it was a Sparc, they flip IDs 0 and 1 (if I remember right) on boot, so we just set the mirror at ID2. This was a great setup, and it worked quite well until one of the drives died and someone (not me, I swear) tried to "dd" to the replacement from the production drive. They crossed-up the "if" and "of" args, so we copied a nice, formatted disk with a spanking new drive label on it over to our produciton webserver drive, that was a bad day. Luckily, the tape was there, and so I say again, get your data on a removable media, keep at least two copies and one HAS to be off-site. I may sound paranoid, but these are reasonable measures for a business that places value on it's data. If your computer makes you any sort of income (tangible or not), the data on that computer is worth, at minimum, what you make off of it, sometimes much more....
Later,
loadc