I'm curious to hear if anyone has looked into kernel scheduling tweaks
or changes in order to improve qd=1/bs=4k performance (while we
patiently wait for Seastar!)
Using this toy cluster:
3x OSD nodes: Atom C3758 (8 core, 2.2GHz) with 1x Intel S4500 SSD each
Debian Bullseye with Linux 5.15.14 and
Hi Dan,
On Fri, Jan 14, 2022 at 6:32 AM Dan van der Ster wrote:
> We had this long ago related to a user generating lots of hard links.
> Snapshots will have a similar effect.
> (in these cases, if a user deletes the original file, the file goes
> into stray until it is "reintegrated").
>
> If yo
> We have test the direct random write for the disk (without Ceph) and it is
> 200 MB/s. Wonder why we got 80MB/s from Ceph.
>
I don't think so, random writes to a hdd do no result in 200MB/s. This is what
I get out of 7k sas
randwrite-4k-seq: (groupid=1, jobs=1): err= 0: pid=10989: Sun Sep 13
Hi,
to have a fair test you need to replicate the power loss scenarios ceph
does cover and you are currently not:
No memory caches in the os or an the disk are allowed to be used, ceph
has to ensure that an object written is actually written, even if a node
of your cluster explodes right at
Hi Marc,
Thanks for your prompt response.
We have test the direct random write for the disk (without Ceph) and it is
200 MB/s. Wonder why we got 80MB/s from Ceph.
Your help is much appreciated.
Regards,
Behzad
On Sun, Jan 16, 2022 at 11:56 AM Marc wrote:
>
>
> > Detailed (somehow) problem de
> Detailed (somehow) problem description:
> Disk size: 1.2 TB
> Ceph version: Pacific
> Block size: 4 MB
> Operation: Sequential write
> Replication factor: 1
> Direct disk performance: 245 MB/s
> Ceph controlled disk performance: 80 MB/s
you are comparing sequential io against random. You shou
And here is the disk information that we base our testing:
HPE EG1200FDJYT 1.2TB 10kRPM 2.5in SAS-6G Enterprise
On Sun, Jan 16, 2022 at 11:23 AM Behzad Khoshbakhti
wrote:
> Hi all,
>
> We are curious about the single disk performance which we experience
> performance degradation when the disk is
Dashboard → Filesystems → (filesystem name) → Directories
fails on a particular file system with error "500 - Internal Server Error".
The log shows:
Jan 16 11:22:18 ceph00 bash[96786]: File
"/usr/share/ceph/mgr/dashboard/services/cephfs.py", line 57, in opendir
Jan 16 11:22:18 ceph00 bash[96
Hi all,
We are curious about the single disk performance which we experience
performance degradation when the disk is controlled via Ceph.
Problem description:
We are curious about the Ceph write performance and we have found that when
we request data to be written via Ceph, it is not using full
