On 10/05/2016 19:31, James Bottomley wrote: > > What about a SPACE ALLOCATION FAILED error or a similar error that > > can be fixed by administrator actions (or just by a concurrent > > process doing an UNMAP)? Would a subsequent cache flush cause data > > loss? > > You're now asking about how these are handled? It's not a SCSI > problem. I believe if you look at the various layers, RAID would still > treat it as fatal and fail the drive and so would most filesystems. > The AEN warnings for TP are reported, but the admin has to sort it out > before they become a fatal error. Thanks, fatal errors are fine I guess. We were worried that the next SYNCHRONIZE CACHE would succeed and throw away the writes because it has already "performed a write medium operation". POSIX fsync is pretty underspecified in this respect too; gluster has been throwing away those writes for a long time! It stopped now because we explained the issue to them, but it's pointless if the next layer below does the same---hence Stefan's question. (In our case the next layer is not the page cache, because we generally use O_DIRECT. Evicting dirty pages from the page cache would be okay if the process(es) that wrote them are SIGKILLed, but in general it would be a problem too). Thanks, Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
