Re: Theoretical question
Aaron J. Grier wrote: > On Fri, Aug 08, 2008 at 03:38:25PM -0700, Steffan Vigano wrote: >> "the LTO tapes only hold 100GB natively, and you can't backup a file >> system with dump that's larger then the actual capacity of the tape." > [...] >> A) Was there any truth to his original statement? > > only if compression is not used, and the partitions are full. (or if > compression is used, and the partitions are full of non-compressible > data.) > In my younger days I did manual backups using dump, and when it hit EOT it would ask for a new tape and wait for you to change tapes and hit y to continue. Made full backups of large filesystems a pain, as you couldn't just start it in cron at let it run (well actually I did, I had it kick off on Saturday morning at a time that would let it be finishing the first tape about the time I planned to stop by to change the tape. Fortunately it fit on two tapes so I wasn't stuck there for hours). Originally, Amanda was not able to backup any filesystem/directory larger than the capacity of a single tape. The ability to span a dump image across multiple tapes was added to Amanda awhile back. Amanda has always had the ability to use tar instead of dump, enabling you to back up subdirectories that would fit on a single tape. Personally, I feel that having a multiple tape dump image just increases the odds of a failed restore, as well as making bare metal recovery without Amanda more difficult. YMMV. Frank -- Frank Smith [EMAIL PROTECTED] Sr. Systems Administrator Voice: 512-374-4673 Hoover's Online Fax: 512-374-4501
Re: Backups to disk and tape
On Sat, Aug 9, 2008 at 9:22 AM, Peter Spikings <[EMAIL PROTECTED]> wrote: > Is that possible? (because I can't see how from reading the man pages). What you're asking about is called D2D2T, and Amanda doesn't support it directly just yet, although preliminary support is a goal for the next release or so. RAIT is the current best option. As long as you're mirroring, there's no problem with deleting a vtape after 7 days. If you need to recover that data, you'll just retrieve the tape and use it directly. So a little bit of shell wrapper can get you up and running with this scheme in no time. I'd be interested to hear folks' high-level thoughts on how D2D2T (or, more generally, data migration) configuration should work in Amanda. Should migration be a separate step from dumping (a la amflush)? Should migration be scheduled somehow (and if so, with what sort of parameters), or should Amanda require explicit instructions on which dumps to migrate and when? We're still laying the low-level groundwork for migration, so there's lots of time to pontificate. Dustin -- Storage Software Engineer http://www.zmanda.com
Re: Theoretical question
On Fri, Aug 08, 2008 at 03:38:25PM -0700, Steffan Vigano wrote: > "the LTO tapes only hold 100GB natively, and you can't backup a file > system with dump that's larger then the actual capacity of the tape." [...] > A) Was there any truth to his original statement? only if compression is not used, and the partitions are full. (or if compression is used, and the partitions are full of non-compressible data.) -- Aaron J. Grier | "Not your ordinary poofy goof." | [EMAIL PROTECTED]
Backups to disk and tape
Hi all, I'm going to be setting up a new Amanda config with tapes going offsite. We're going to be using 30 tapes or so. As the tapes leave straight away after being written we want to keep copies of the data written to them on disk for (say) 7 days. I've looked into using RAIT to do this but wouldn't I then need enough diskspace to hold all the data on all the tapes? It strikes me that a good way to do this would be to allocate 7 tapes worth of space to the holding disk and have Amanda delete the older data when it needs to as Amanda can already restore from the holding disk. Is that possible? (because I can't see how from reading the man pages). Thanks, Peter. PS. Probably won't be able to respond until Monday! -- Peter Spikings Research & Development Software Developer Powergroup Two Four Nine, 249 Midsummer Boulevard, Central Milton Keynes, MK9 1EA t: 01908 605188 f: 01908 242099 e: [EMAIL PROTECTED] www.powergroup.co.uk www.powernet.co.uk www.powercorporate.co.uk Power Internet Limited Registered in England No: 3053650 Registered Address: Norfolk House Centre, 82 Saxon Gate West, Central Milton Keynes, Bucks, MK9 2DL Trading as "Powergroup", "Powernet", "Powercorporate" and "Powertelecom"
