From: Stefan Priebe <s.priebe@profihost.ag>
To: "ceph-devel@vger.kernel.org" <ceph-devel@vger.kernel.org>
Subject: extreme ceph-osd cpu load for rand. 4k write
Date: Wed, 07 Nov 2012 21:41:22 +0100 [thread overview]
Message-ID: <509AC772.5010606@profihost.ag> (raw)
Hello list,
whiling benchmarking i was wondering, why the ceph-osd load is so
extreme high while having random 4k write i/o.
Here an example while benchmarking:
random 4k write: 16.000 iop/s 180% CPU Load in top from EACH ceph-osd
process
random 4k read: 16.000 iop/s 19% CPU Load in top from EACH ceph-osd process
seq 4M write: 800MB/s 14% CPU Load in top from EACH ceph-osd process
seq 4M read: 1600MB/s 9% CPU Load in top from EACH ceph-osd process
I can't understand why in this single case the load is so EXTREMELY high.
Greets
Stefan
next reply other threads:[~2012-11-07 20:41 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-07 20:41 Stefan Priebe [this message]
2012-11-08 14:58 ` extreme ceph-osd cpu load for rand. 4k write Stefan Priebe - Profihost AG
2012-11-08 15:01 ` Sage Weil
2012-11-08 15:45 ` Stefan Priebe - Profihost AG
2012-11-08 16:06 ` Mark Nelson
2012-11-08 21:27 ` Stefan Priebe
2012-11-08 21:50 ` Josh Durgin
2012-11-08 21:58 ` Mark Nelson
2012-11-08 22:06 ` Stefan Priebe
2012-11-08 22:31 ` Stefan Priebe
2012-11-09 10:09 ` Stefan Priebe - Profihost AG
2012-11-09 10:21 ` Stefan Priebe - Profihost AG
2012-11-09 21:21 ` Samuel Just
2012-11-09 21:34 ` Stefan Priebe - Profihost AG
2012-11-10 20:36 ` Samuel Just
2012-11-10 20:37 ` Samuel Just
2012-11-10 20:43 ` Stefan Priebe
2012-11-10 20:42 ` Stefan Priebe
2012-11-08 15:01 ` Mark Nelson
2012-11-08 15:45 ` Stefan Priebe - Profihost AG
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=509AC772.5010606@profihost.ag \
--to=s.priebe@profihost.ag \
--cc=ceph-devel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox