On Fri, 2005-12-02 at 08:52 -0700, Nicholas Leippe wrote: > On Friday 02 December 2005 07:54 am, Ross Werner wrote: > > I can understand databases, but any application that produces temporary > > files ... well, won't that just mean you won't copy all the temporary > > files with 100% accuracy? I mean, they're *temporary* ... in the event of > > a complete data loss and restore from backups, won't restarting the > > service or whatever application it is flush those temporary files, making > > losing temporary files of little concern? > > It depends on their lifespan. Temporary doesn't necessarily imply not > being used to store state between invocations.
Well if you need to switch to you backup disk, you are most likely going to have to experience some down time anyway, so the server processes will have to restart, thus the temporary files won't mean a whole lot. A catastrophic disk failure will also likely bring the whole machine down uncleanly anyway. Most server apps can deal with an unclean recovery. > > > I'm just wondering if there's anything in a typical Linux server > > installation that won't typically survive a 2 AM rsync. > > What about mail files and their corresponding index files? Not a problem. They are locked on write-access anyway (fairly coarse granularity too with mbox). Of course if the file changes while it is being backed up, you just get a snaphot of the file before the change happened. On any system that allows multiple sources to read and write same file (say the mail spool), access is always controlled by locking. Otherwise the imap daemon would clobber the file if the MTA tried to deliver a message at the same time someone was checking their e-mail. Even in a worse-case scenerio, a slightly corrupted mbox (which can be fixed with a text editor) can be dealt with. I recommend converting to Maildir, however, and you'll never have to deal with that type of corruption. The only things that can't be backed up live are databases, sql, bdb, etc. For example, I backup ldap by dumping an ldif file and backing that up. Mail spoools. home directories, the web server's config and webroot, the name server, etc, all can be backed up live just fine. I don't see any problems backing up a live system in the middle of the night. > -- Michael Torrie <[EMAIL PROTECTED]> /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
