[pbs-devel] [PATCH proxmox-backup 0/5] GC: avoid multiple atime updates

[Roland]

 > 34742 proxmox-backup-(1428): R
 > /backup/pve-t620_backup/.chunks/bb9f/
bb9f8df61474d25e71fa00722318cd387396ca1736605e1248821cc0de3d3af8
 > any clue what's this one,  which is being touched an order of magnitude
 > more often then the zeroes chunk ?
 > I do not have that particular chunk digest in my datastores, but if
the chunk is not encrypted, you could just decompress it and inspect the
contents via a hex editor.

apparently, this is also an "all zero" chunk, but from a different
backup datastore where encryption is active.
after thinking twice, this looks logical to me....

Am 21.02.25 um 16:49 schrieb Christian Ebner:
> On 2/21/25 16:35, Roland wrote:
>> hello,
>>
>> this looks like this relates to or adresses what's being mentioned
>> here ?
>>
>> https://forum.proxmox.com/threads/better-understand-proxmox-garbage-
>> collection-lots-of-avoidable-utimensat-calls.101417/
>> ?
>>
>> it came to my mind when reading this.  not sure if i did an RFE for
>> this, guess i forgot...
>
> Yes, this has been requested also by others, see the discussion in
> https://bugzilla.proxmox.com/show_bug.cgi?id=5331
>
> The (still initial) title of the issue is a bit misleading, as the
> implementation in the patch series works for all chunks, not just the
> zero chunks. ;)
>
>>
>>  >for my curiosity, i see there is one chunk in both of my homeserver
>> repos which is accessed orders of magnitudes more often then all
>>  >the other chunks (for one repo roundabout 1000x more often) during gc
>> run. anyhow, many chunks are being acessed repeatedly, but at a much
>> lower rate.
>>
>> ah, now i understand why that file is touched 34742 times - it's that
>> "all zeroes" chunk, which does occur in the vm image much more often.
>
> Haven't check that yet, but most likely yes, I do have the same chunk
> in my datastore.
>
>>
>> 34742 proxmox-backup-(1428): R
>> /backup/pve-t620_backup/.chunks/bb9f/
>> bb9f8df61474d25e71fa00722318cd387396ca1736605e1248821cc0de3d3af8
>>
>> any clue what's this one,  which is being touched an order of magnitude
>> more often then the zeroes chunk ?
>
> I do not have that particular chunk digest in my datastores, but if
> the chunk is not encrypted, you could just decompress it and inspect
> the contents via a hex editor.
>
>>
>> 940079 proxmox-backup-(1428): R
>> /backup/pve-maker-
>> bonn_backup/.chunks/7b27/7b27b1eb4febae3273321255d8304e9b3e7938d9e254564bef859a4307a88638
>>
>> regards
>> roland
>
> Cheers,
> Chris
>
>