Re: fio test triggering bad data on ext4

Eric Sandeen
2010-06-18T14:59:25Z

Eric Sandeen wrote:
> Jens Axboe wrote:
>> Hi,
>>
>> I was writing a small fio job file to do writes and read verifies on a
>> device. It forks 32 processes, each writing randomly to 4 files with a
>> block size between 4k and 16k. When it has written 1024 of those blocks,
>> it'll verify the oldest 512 of them. Each block is checksummed for every
>> 512b. It uses libaio and O_DIRECT.
>>
>> It works on ext2 and btrfs. I haven't run it to completion yet, but they
>> survive 15-20 minutes just fine. ext4 doesn't even go a full minutes
>> before this triggers:
>
> Jens, can you try XFS too? Since ext3 can't do direct IO to a hole,
> (and I'm not sure about btrfs in that regard), ext4 may be most similar
> to xfs's behavior on the test ... wondering how it fares.
>
> Thanks,
> -Eric

Actually mingming had a patch for direct-io.c which may be related, I'll
test that out.

-Eric