Re: garbage collect: free orphaned chunks from disks?
On Wed, Mar 08, 2023 at 12:20:00PM +0100, Heiko Schlittermann wrote: Hi, Jens Berg (Mi 08 Mär 2023 10:06:34 CET): She does in the moment a tape (= slot) is re-used. … Remember that amanda was initially designed to work with tapes and that Olivier (Mi 08 Mär 2023 11:46:37 CET): While the tape/slot could free the level 1 dumps for a-disk, there could be some DLE for other disks/hosts that are still valid on that tape/slot. Yes, I know that amanda was designed for tapes initially (and I'm still using it happily with tapes.). The "disk garbage collection" was just a minor issue I found when checking what space is available on one of our disk based backup servers. Thanks for the input. Thinking outside of amanda provided tools: 1. Assuming tar is your backup program, the "garbage" files do still contain recoverable data. I did make use of this "once" to recover a file deleted just before that oldest full dump. 2. The files on vtapes are named such that a find(1) command could be constructed to scan the backup disks looking for the "garbage" files (they would be "older" than the oldest full dump) and either list them or delete them. jl -- Jon H. LaBadie j...@labadie.us 154 Milkweed Dr (540) 868-8052 (H) Lake Frederick, VA 22630(703) 935-6720 (M)
Re: garbage collect: free orphaned chunks from disks?
I would also like to add that it is good to have backups from varying dates around in case the most recent backup is ex after a file was accidentally deleted and you need to restore it from an older backup. Anton "exuvo" Olsson ex...@exuvo.se On 2023-03-08 12:20, Heiko Schlittermann wrote: Hi, Jens Berg (Mi 08 Mär 2023 10:06:34 CET): She does in the moment a tape (= slot) is re-used. … Remember that amanda was initially designed to work with tapes and that Olivier (Mi 08 Mär 2023 11:46:37 CET): While the tape/slot could free the level 1 dumps for a-disk, there could be some DLE for other disks/hosts that are still valid on that tape/slot. Yes, I know that amanda was designed for tapes initially (and I'm still using it happily with tapes.). The "disk garbage collection" was just a minor issue I found when checking what space is available on one of our disk based backup servers. Thanks for the input.
Re: garbage collect: free orphaned chunks from disks?
Hi, Jens Berg (Mi 08 Mär 2023 10:06:34 CET): > She does in the moment a tape (= slot) is re-used. … > Remember that amanda was initially designed to work with tapes and that Olivier (Mi 08 Mär 2023 11:46:37 CET): > While the tape/slot could free the level 1 dumps for a-disk, there could be > some DLE for other disks/hosts that are still valid on that tape/slot. Yes, I know that amanda was designed for tapes initially (and I'm still using it happily with tapes.). The "disk garbage collection" was just a minor issue I found when checking what space is available on one of our disk based backup servers. Thanks for the input. -- Heiko signature.asc Description: PGP signature
Re: garbage collect: free orphaned chunks from disks?
Hi, > Given a series of dumps like > > a-host a-disk 1 1 1 0 1 1 > > the left most level 1 dumps are worthless, because we already dropped > the "base" level 0. While the tape/slot could free the level 1 dumps for a-disk, there could be some DLE for other disks/hosts that are still valid on that tape/slot. I don't think Amanda has any way to free some specific DLE from a tape/slot. It is only at the tape/slot level that a tape/slot can be erased and reused. Best regards, Olivier
Re: garbage collect: free orphaned chunks from disks?
On 08.03.2023 08:14, Heiko Schlittermann wrote: - Does amanda delete these files? From the output of `amadmin find` it does not look as if it does. She does in the moment a tape (= slot) is re-used. Remember that amanda was initially designed to work with tapes and that using disks as backup media has been implemented by emulating a classical tape library. With real tapes it would be an extremely costly operation to fetch and (partially) overwrite all older backups of a DLE once a level 0 has been written. Sure, if amanda knew she was operating on disks rather than on tapes she could do so easily. But what would be the benefit?
garbage collect: free orphaned chunks from disks?
Hi,
if I understand and observed well, then for a disk based backup we have the
chunks as
single files in the slot* directories.
Given a series of dumps like
a-host a-disk 1 1 1 0 1 1
the left most level 1 dumps are worthless, because we already dropped
the "base" level 0.
- Does amanda delete these files? From the output of `amadmin find` it
does not look as if it does.
- Is there any pre-existing tool / procedure to do so?
- If not:
- Would this be useful?
- Where would you look for it?
- Where would it fit best (amtape? amadmin? amcleanup?)
Best regards from Dresden/Germany
Viele Grüße aus Dresden
Heiko Schlittermann
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