If the disk is 2TB, then your 100GB test is only using 5% of it-- thus your observed IOPS will be a lot better than expected due to short-stroking. Right? On Nov 10, 2010, at 11:58 AM, Sebastian Kayser <sebastian@xxxxxxxxxx> wrote: > * Sebastian Kayser <sebastian@xxxxxxxxxx> wrote: >> What I will do now is to export the whole 2TB of the disk (instead of >> just 10GB) and increase size= to see whether that makes any difference >> (hopefully). Other than that, further ideas? > > Interim update. Exported the whole 2TB disk as a LUN, mkfs.ext3'd it and > set size=100g in fio's configuration. Also set runtime=1800, re-started > the test and could observe ~80 IOPS ... my dear heart was jumping with > joy :) > > However, a few minutes into the test, IOPS started to increase steadily > and by now have again reached (non-bursty) regions that don't seem > plausible for a single 7.2K SATA disk. > > root@ubuntu-804-x64:~# ./fio --section=iscsi patterns.fio > iscsi: (g=0): rw=randwrite, bs=4K-4K/4K-4K, ioengine=sync, iodepth=1 > Starting 1 process > iscsi: Laying out IO file(s) (1 file(s) / 102400MB) > Jobs: 1 (f=1): [w] [48.4% done] [0K/986K /s] [0/240 iops] [eta 15m:28s] > > root@ubuntu-804-x64:~# cat patterns.fio > [global] > size=100g > runtime=1800 > direct=1 > sync=1 > overwrite=1 > > [iscsi] > directory=/mnt > rw=randwrite > > root@ubuntu-804-x64:~# df -h /mnt > Filesystem Size Used Avail Use% Mounted on > /dev/sdb1 1.9T 101G 1.7T 6% /mnt > > Well, I am so used to see less IOPS than hoped for ... but obviously not > this time and it's driving me crazy :) Any further thoughts greatly > appreciated. > > Sebastian > -- > To unsubscribe from this list: send the line "unsubscribe fio" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
