On 03/05/2012 10:11 AM, Stefan Hübner wrote: > -------- Original Message -------- > Subject: Re: Re-2: verify seems not to take place on iSCSI-Target writing (02-Mrz-2012 19:46) > From: Jens Axboe <axboe@xxxxxxxxx> > To: shu@xxxxxxxxxx > >> On 2012-03-02 18:06, Stefan Hübner wrote: >>> Dear Jens, >>> >>> this is the output. I added some supplementary details in the hope it's >>> useful ... >>> >>> UltraBitch ~ # ISCSI_DEVICE=/dev/sdb SECONDS=$((20*3600)) fio iscsi-stress. >>> fio >>> iSCSI: (g=0): rw=randwrite, bs=4K-4M/4K-4M, ioengine=libaio, iodepth=16 >>> fio 2.0.3 >>> Starting 1 process >>> Jobs: 1 (f=1): [w] [17.3% done] [0K/113.2M /s] [0 /71 iops] [eta 03d:23h: >>> 28m:21s] >>> iSCSI: (groupid=0, jobs=1): err= 0: pid=18184 >>> write: io=7740.2GB, bw=112723KB/s, iops=63 , runt=72000222msec >>> bw (KB/s) : min= 3669, max=593424, per=100.00%, avg=113561.25, stdev= >>> 26868.27 >>> cpu : usr=4.18%, sys=1.28%, ctx=4760480, majf=0, minf=106912 >>> IO depths : 1=0.1%, 2=0.1%, 4=0.1%, 8=0.1%, 16=100.0%, 32=0.0%, >=64=0. >>> 0% >>> submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64= >>> 0.0% >>> complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.1%, 32=0.0%, 64=0.0%, >=64= >>> 0.0% >>> issued : total=r=0/w=4560578/d=0, short=r=0/w=0/d=0 >>> >>> Run status group 0 (all jobs): >>> WRITE: io=7740.2GB, aggrb=112723KB/s, minb=115428KB/s, maxb=115428KB/s, >>> mint=72000222msec, maxt=72000222msec >> >> No reads happened - quick guess, you had the timeout hit before the >> write phase has finished. Hence it'll exit, and don't do verifies. >> >> The reads you saw in the stats must be from other processes. Fio didn't >> do any. >> >> -- >> Jens Axboe >> > Hi Jens, > > then I don't quite understand what sense "verify_async" makes. I > thought it'd do the verifies "in parallel". > > Any hint's how to get a timebased torture-test with verify working? You didn't add a specific backlog for the verify threads. Granted that's a bit confusing... But you want to tell fio how far behind the verify threads are running. So if you set verify_backlog=32 for instance, it will be 32 ios behind the writer. That will give you a job that continually randomly writes and verifies as it goes, the kind of torture I think you are looking for. verify_async=2 just tells fio to allocate 2 threads for doing verifies. -- Jens Axboe -- 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
