Hi,
On Thu, Feb 20, 2014 at 7:47 PM, Gregory Farnum <greg@xxxxxxxxxxx> wrote:
On Tue, Feb 18, 2014 at 8:21 AM, Dan van der SterI'm not sure if this reasoning is quite right. If you had hashpspool
<daniel.vanderster@xxxxxxx> wrote:
> Hi,
> Today I've noticed an interesting result of not have hashpspool
> enabled on a number of pools -- backfilling is delayed.
>
> Take for example the following case: a PG from each of 5 different
> pools (details below) are all mapped to the same three OSDs: 884,
> 1186, 122. This is of course bad for data distribution, but I realised
> today that it also delays backfilling. In our case we have osd max
> backfills = 1, so the first 4 PGs listed below all have to wait for
> 32.1a1 to finish before they can start. And in this case, pool 32 has
> many objects, with low importance, whereas pools 4 and 5 have high
> importance data that I'd like backfilled with priority.
enabled, you would still have sets of OSDs that share PGs across each
of the pools, and your max backfill params would still limit how many
of them could backfill at a time. They just wouldn't be sequentially
numbered.
OK I guess we'll get some experience with that once we have all hashpspool'd pools.
>Sadly no; I don't think we've ever talked about either of these. This
> Is there a way (implemented or planned) to prioritise the backfilling
> of certain pools over others?
> If not, is there a way to instruct a given PG to begin backfilling right away?
sounds like it would be a good feature request in the tracker, or
maybe a good blueprint for the upcoming summit if you can flesh out
the UI you'd like to see.
OK great!
We discussed it but didn't think there was much point -- if you need to
> And a related question: will
> ceph osd pool set <poolname> hashpspool true
> be available in a dumpling release, e.g. 0.67.7? It is not available
> in 0.67.5, AFAICT.
enable hashpspool you can do so by extracting, manually editing, and
injecting the crush map. :)
How does that work? Our decompiled crush maps don't mention pools:
ceph osd getcrushmap -o crush.map
crushtool -d crush.map -o crush.txt
no pools nor pool flags in crush.txt
Cheers, Dan
-Greg
> _______________________________________________
>
> Cheers, Dan
>
> 2.1bf active+degraded+remapped+wait_backfill [884,1186,122] [884,1186,1216]
>
> 6.1bb active+degraded+remapped+wait_backfill [884,1186,122] [884,1186,1216]
>
> 4.1bd active+degraded+remapped+wait_backfill [884,1186,122,841]
> [884,1186,182,1216]
>
> 5.1bc active+degraded+remapped+wait_backfill [884,1186,122,841]
> [884,1186,182,1216]
>
> 32.1a1 active+degraded+remapped+backfilling [884,1186,122] [884,1186,1216]
>
> full details at:
>
> http://pastebin.com/raw.php?i=LBpx5VsD
>
> -- Dan van der Ster || Data & Storage Services || CERN IT Department --
> ceph-users mailing list
> ceph-users@xxxxxxxxxxxxxx
> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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