fio single job randrw md5 verify failure

[changchengx]

For data integrity md5 verification, is it normal to use this option when doing randrw test?
For example: sudo fio --bs=1M --iodepth=256 --numjobs=1 --runtime=60 --filename=/dev/vda --rw=randrw --name=test-rw --ioengine=libaio --direct=1 --time_based --verify=md5

[changchengx]

@sitsofe could you help check this question?

[vincentkfu]

Run this with --debug=io,verify to gain some insight into what fio is doing. It looks like fio is writing IOs with verification headers but just doing regular reads.

You could try something like:

fio --bs=1M --iodepth=256 --numjobs=1 --filename=/dev/vda--rw=randwrite --name=test-rw --ioengine=libaio --direct=1 --verify=md5 --debug=io,verify

Fio will randomly write the device and then verify/read all of the blocks written.

[changchengx]

@vincentkfu I'll try to run the test with --debug=io,verify. Is it right to do md5 verification under randrw test instead of randwrite test?

[vincentkfu]

I would use the command I suggested which includes rw=randwrite for your test. Drop time_based and runtime and just let fio write the entire device. After the write phase is complete fio will then verify the data just written.