Re: Raid and Amanda
On Wed, Jun 06, 2001 at 08:44:27AM -0400, Karl Bellve wrote: I am learning to use Amanda but it seems it has a problem, as everyone knows, backing up a filesystem larger than the tape. I have a 300GB Raid 5 system and a 35GB AIT tape drive. I would like to do a backup of the raid system with a full backup done atleast once/month. It seems the only option is to make a Amanda config file for each subdirectory inside the raid drive (limited to 10GB each). There are about 15 10GB directories, so I guess I need to make 15 config files? If you use tar (as opposed to dump) as the low-level utility, you can use a single amanda config, with a line in the disklist for each 10G subdirectory. Will Amanda try and back up each 10GB directory each night? I can see that would be a problem since I don't have a tape changer. Also, my holder partition is only about 2GB. I fail to see how it could be practical to use a separate amanda configuration per subdirectory. You'd have to run, say, a different configuration per night on a fifteen-day rotation. Not very good coverage! -- - Dan Wilder [EMAIL PROTECTED] Technical Manager Editor SSC, Inc. P.O. Box 55549 Phone: 206-782-8808 Seattle, WA 98155-0549URL http://embedded.linuxjournal.com/ -
Re: Raid and Amanda
Olivier Nicole wrote: I am learning to use Amanda but it seems it has a problem, as everyone knows, backing up a filesystem larger than the tape. Am I wrong? I understood that Amanda is supposed to ask for as many tapes during a single run, that are needed to complete the back-up. So it would start and ask for a second, third, fourth... tape until it managed to back-up everything. A backup of an individual filesystem cannot span multiple tapes. For example, if you have a 40 GB tapedrive, and you want to back up a 75 GB disk drive that is pretty full of data that is not very compressible, it's probably not going to work. You will have to use gnutar to split up the disk into smaller subdirectories. Or, you might consider backing up the disk and then repartitioning it into 40 GB chunks. I think that spanning multiple tapes may be a feature in some development version of amanda, but I don't know the current status. Secondly, runtapes determines the total number of tapes that amanda will use during the run, period. You could set runtapes equal to the number of tapes in your changer and let amanda use all of the tapes until it is done, but that may not be the ideal strategy in the long term. You may want to try to get amanda to use about 2-3 tapes a day, for example, and balance the full and incremental dumps accordingly. You have to try to be realistic about how many tapes you will need to use, but things will also balance out some as the dump cycle progresses. What I do is during the week, I only let amanda use 2-3 tapes for each run. Sometimes, dumps end up left on the holding disk, and I have to flush them to tape, but at least it keeps the backup cycle from running into the middle of the work day if there are some large dumps that need to get done. For the weekend, I let amanda use all of the tapes in the rack if it wants to. I will also deliberately force a few full dumps to try to get them done on the weekend so they won't run during the week. One thing I haven't worked out yet is a good system for trying to guess what full dumps should be coming due soon so I can specifically force those dumps on the weekend. -- Jonathan F. Dill ([EMAIL PROTECTED]) CARB Systems and Network Administrator Home Page: http://www.umbi.umd.edu/~dill
Re: Raid and Amanda
Oh? If you use tar (as opposed to dump) as the low-level utility, you can use a single amanda config, with a line in the disklist for each 10G subdirectory. I didn't know one could do that. How? DSL -- ACCUSATION: David Newall, you have not read your Microsoft Manual REPLY: No I haven't (quoting David Newall with permission)
Re: Raid and Amanda
If you use tar (as opposed to dump) as the low-level utility, you can use a single amanda config, with a line in the disklist for each 10G subdirectory. I didn't know one could do that. How? OK lets suppose you mount /dev/da0s1g to /home for the users home directories. In /home, you will have one subdirectory per user, /home/paul, /home/peter... So in you amada disklist, you just declare /home/paul, then on an other line /home/peter... Assuming that each user is less than the 10GB of course. And the dumptype in amanda.conf must specify to use GNUTAR Olivier
Re: Raid and Amanda
On Wed, 6 Jun 2001 at 10:51pm, Olivier Nicole wrote I am learning to use Amanda but it seems it has a problem, as everyone knows, backing up a filesystem larger than the tape. Am I wrong? I understood that Amanda is supposed to ask for as many tapes during a single run, that are needed to complete the back-up. So it would start and ask for a second, third, fourth... tape until it managed to back-up everything. It will use as many tapes as it needs during a single amdump run *if* you set runtapes large enough and define a tape changer (including you, a.k.a chg-manual). -- Joshua Baker-LePain Department of Biomedical Engineering Duke University
