Re: Memstore issue on v0.91

[Mark Nelson <mark.nelson@inktank.com>]

On 01/21/2015 01:48 AM, Blinick, Stephen L wrote:
> Moved to 0.91 yesterday and ran into some issues, with a Memstore OSD of default size.  After a few hundred K OPS client gets a FULL message and the avail space looks like:
>
> [root@cephtestnode0 bmpa]# rados df
> pool name                 KB      objects       clones     degraded     unfound           rd        rd KB           wr        wr KB
> rbd                        0            0            0            0          0            0            0            0            0
> testmemstore         1505052       376263            0            0          0            0            0       376263      1505052
>    total used         1494247       376263
>    total avail   18014398508987737
>    total space        1000000
>
> I was looking at pull request #2836 and found a case where there could be an unsigned int underflow in MemStore.cc:statfs:
>
>     st->f_bfree = st->f_bavail = MAX((st->f_blocks - used_bytes / st->f_bsize), 0);
>
> But that wasn't the final issue.. I put some asserts where used_bytes could underflow as well and didn't catch anything.  I will keep digging but wanted to find out if anyone else was seeing the issue as well.

FWIW, I hit this yesterday too.  I hadn't started debugging it yet 
though.  Looks like you are farther along than I am, thanks Stephen! :)

>
> Thanks,
>
> Stephen
>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>