W dniu 2017-02-13 o 13:44 PM, Austin S. Hemmelgarn pisze: > On 2017-02-09 22:58, Andrei Borzenkov wrote: >> 07.02.2017 23:47, Austin S. Hemmelgarn пишет: >> ... >>> Sadly, freezefs (the generic interface based off of xfs_freeze) only >>> works for block device snapshots. Filesystem level snapshots need the >>> application software to sync all it's data and then stop writing until >>> the snapshot is complete. >>> >> >> I expect databases to be using directio, otherwise we have problems even >> without using snapshots. Is it still an issue with directio? > It is less of an issue, but it's still an issue because you can still > call for snapshot creation in the middle of an application I/O > request. In other words, the application wouldn't need to worry about > syncing data, but it would need to worry about making sure it's not > actually writing anything when the snapshot happens. > I think this should work the other way around. Snapshot should wait until all directio writes are done,
and new requests sent when creating snapshot, should wait until snapshot is done. -- Adrian Brzeziński -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
