thx a lot Sitofe I'm using only libaio and I'm parsing the output Json file I was looking to see if there is a unique msg for data corruption but it's look like every other IO error --Udi On Mon, Sep 11, 2017 at 10:43 PM, Sitsofe Wheeler <sitsofe@xxxxxxxxx> wrote: > Hi, > > On 11 September 2017 at 18:24, Udi-Yehuda Tamar <udi@xxxxxxxxxxxx> wrote: >> I guess this question answers it's self but I'll give it a try , >> Can Fio tell for sure the IO err is a data corruption ? say the drive >> is busy and the read failed >> but not necessarily on data corruption can Fio tell that? >> I guess not! because every IO failure can be a data corruption , but I >> prefer a pro answer - thx in adv. > > This depends on how the ioengine and the layers beneath handle it. For > example the psync ioengine talks to a filesystem or block device and > in Linux there's typically some sort of error handling that happens > below the block layer (see > http://events.linuxfoundation.org/sites/events/files/slides/SCSI-EH.pdf > for how this happens for SCSI) so if the kernel (or the disk itself!) > has handled the error by retrying then all userspace (and thus fio) > will see is success but the latency for I/Os that get caught up might > look abnormally high or the I/O will return with an error like EIO. > fio can be made to abort if an I/O returns with high latency (see the > max_latency option - > http://fio.readthedocs.io/en/latest/fio_doc.html#cmdoption-arg-max-latency). > > Different I/O engines may be able to return different types of error > depending on what they are talking to and what level they operate at. > For example the sg ioengine sets a timeout of 30 seconds but it looks > like this still makes error handling kick in (see > http://sg.danny.cz/sg/p/sg_v3_ho.html#id2495241 ). > > I don't know if this answer is "pro" enough for you though... > > -- > Sitsofe | http://sucs.org/~sits/ -- Thanks, Udi-Yehuda Tamar. -- 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
