Got it thanks ________________________________________ From: Sitsofe Wheeler <sitsofe@xxxxxxxxx> Sent: 12 December 2018 02:27:11 To: Mohan Mohan Cc: fio Subject: Re: err=84/file:io_u.c:2033, func=io_u_sync_complete, error=Invalid or incomplete multibyte or wide character Hi, On Tue, 11 Dec 2018 at 18:01, Mohan Mohan <mohan@xxxxxxxxxx<mailto:mohan@xxxxxxxxxx>> wrote: Hi, Is the error below is expected one for the read operation? I am not getting any error for the write operation. root@ertino-ThinkPad-T431s:/home/ertino--verify crc32c ^^^ It looks like you asked for verifying reads (although this line looks mangled - it's hard to tell without seeing the full job). xspp: (g=0): rw=randread, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=psync, iodepth=1 fio-3.12-17-g0fcbc0 Starting 1 process xspp: Laying out IO file (1 file / 10MiB) verify: bad magic header 1950, wanted acca at file xspp.0.0 offset 630784, length 4096 (requested block: offset=630784, length=4096) ^^^ This is saying that the block read lacked the expected fio header. fio: pid=32055, err=84/file:io_u.c:2033, func=io_u_sync_complete, error=Invalid or incomplete multibyte or wide character xspp: (groupid=0, jobs=1): err=84 (file:io_u.c:2033, func=io_u_sync_complete, error=Invalid or incomplete multibyte or wide character): pid=32055: Tue Dec 11 23:09:30 2018 I'm guessing you asked fio to do verifying reads (e.g. fio --name=verifread --rw=read --verify=crc32c --size=1M --filename=fio.tmp) *before* you wrote data with a verify header. Unless you have already written all of the file that is being read back file with appropriate verification headers (i.e. you ran a write job first) then it's expected fio will complain about not being able to read the expected headers. A write job won't have this problem because it writes data (sometimes before trying to read it back). See https://fio.readthedocs.io/en/latest/fio_doc.html#cmdoption-arg-verify for details. -- Sitsofe | http://sucs.org/~sits/