FUJITA Tomonori schrieb: >>> Here is a lengthy log for 25 minutes - with several device >>> suspends/resumes. >>> I'll give it 2 more hours testing... >> Not 2 hours, but some observations - is it possible that tgtd serves >> wrong data to the initiator when the access to the media is slow? > > tgtd doesn't return wrong (bogus) data. > > The initiator has to give up I/O requests at some point if the target > doesn't send responses for long time. Then you see the I/O errors. I have the timeout set to several days, so it doesn't give up within single minutes. I can shut the target down for days, and the initiator will recover nicely when the target is back. node.session.timeo.replacement_timeout = 1000000 And here, we had no network disconnections/malfunctions. > Or on the target side, the kernel gives tgtd I/O errors if the backing > store doesn't return responses for long time. Then tgtd sends the > errors to the initiator. No, there were no I/O errors on the target machine. Any I/O error would be reported in dmesg; I didn't have any of such errors. (...) > And you see something like this in the kernel log: > > sd 1:0:0:0: Device offlined - not ready after error recovery > sd 1:0:0:0: [sdd] Unhandled error code<6>sd 1:0:0:0: [sdd] Result: > hostbyte=DID_OK driverbyte=DRIVER_TIMEOUT,SUGGEST_OK > end_request: I/O error, dev sdd, sector 0 > Buffer I/O error on device sdd, logical block 0 > Buffer I/O error on device sdd, logical block 1 > Buffer I/O error on device sdd, logical block 2 > Buffer I/O error on device sdd, logical block 3 > sd 1:0:0:0: rejecting I/O to offline device > Buffer I/O error on device sdd, logical block 0 > > > You can replace dd with tgtd in the above example. Exactly - you had errors in the kernel log. I didn't have anything like that on the machine running tgtd. The initiator machine did have these errors, though. -- Tomasz Chmielewski http://wpkg.org -- To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html |