I use fio.
#1. Be sure to have a job that writes random data to 100% of the RBD device
before starting. I use the size=100%.
#2. Benchmark something that makes sense for your use case, eg. benchmarking
1M sequential writes makes no sense if your workload is 64k random.
#3. A follow on to number 2. If the workload is latency sensitive, use
latency targets. The following settings ramp up to queue depth to find the
maximum setting that keeps 99.99999% of I/Os inside the 10ms latency target
over a 5 second window:
latency_target=10ms
latency_window=5s
latency_percentile=99.99999
#4. Use the ramp_time option to cut off data at the front of the test. This
will remove initial spikes from the data.
#5. Use long running tests with larger data sets. Short tests will exhibit
the results of caching, and that may be okay at times, but generally, it’s a
good idea to have a long running test (30+ minutes) that demonstrates the
cluster’s performance under steady load.
David Byte
Sr. Technology Strategist
SCE Enterprise Linux
SCE Enterprise Storage
Alliances and SUSE Embedded
db...@suse.com<mailto:db...@suse.com>
918.528.4422
From: ceph-users <ceph-users-boun...@lists.ceph.com> on behalf of Nino Bosteels
<n.boste...@proximedia.be>
Date: Tuesday, June 19, 2018 at 7:08 AM
To: "ceph-users@lists.ceph.com" <ceph-users@lists.ceph.com>
Subject: [ceph-users] Benchmarking
Hi,
Anyone got tips as to how to best benchmark a Ceph blockdevice (RBD)?
I’ve currently found the more traditional ways (dd, iostat, bonnie++, phoronix
test suite) and fio which actually supports the rbd-engine.
Though there’s not a lot of information about it to be found online (contrary
to e.g. benchmarking zfs).
Currently I’m using this, closest to the usage of BackupPC-software available
(small randreads) with fio:
[global]
ioengine=rbd
clientname=admin
pool=[poolname]
rbdname=[rbdname]
rw=randread
randrepeat=1
direct=1
ramp_time=4
bs=4k
[rbd_iodepth32]
iodepth=32
Any ideas (or questions) welcome !
Nino
_______________________________________________
ceph-users mailing list
ceph-users@lists.ceph.com
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
