On Wed, Sep 22, 2010 at 10:07 AM, Jon LaBadie <j...@jgcomp.com> wrote: > Any thoughts on how desireable you feel be a separate > copy of amanda data would be and other approaches?
This comes up often, and I've never found a solution I'm happy enough with to make the "official" solution. Gene's approach is the obvious one, but has a few limitations: - What do you do if you run out of space on that tape? Start a new tape? How do you reflect the use of that new tape in the catalog? - How does recovery from that metadata backup work? There's a chicken-and-egg problem here, too - you'll need an Amanda config to run any Amanda tools other than amrestore. Let's break down "metadata" into its component parts, too: 1. configuration 2. catalog (logdir, tapelist) 3. indexes 4. performance data (curinfo) 5. debug logs Configuration (1) can be backed up like a normal DLE. The catalog (2) should technically be recoverable from a scan of the tapes themselves, although the tool to do this is still awaiting a happy hacker to bring it to life. Indexes (3) are only required for amrecover, and if your Amanda server is down, you likely want whole DLEs restored, so you only need amfetchdump. Performance data (4) will automatically regenerate itself over subsequent runs, so there's no need to back it up. Similarly, debug logs (5) can get quite large, and generally need not be backed up. So, to my mind, the only component that needs special handling is the catalog, and we have a menu of ways to handle that: - append a copy of the entire catalog to the last tape in each run (hey, what is the "last tape" now that we have multiple simultaneous tapers?) - append a copy of only the catalog for that run to the last tape in each run - finally get around to writing 'amrecatalog' - rsync the entire catalog to another machine nightly I just stuck that last one in because it was my technique back when I managed a fleet of Amanda servers. Each would simply rsync its config and catalog to the other servers. Since they were all backing up to shared storage (a SAN), I could do a restore / amfetchdump / recovery of any dump on any server without trouble. It's a very non-Amanda-centric solution, but it's *very* effective. Dustin -- Open Source Storage Engineer http://www.zmanda.com
