Hello Hamish, > * The commit interval is set to 30 seconds instead of the default 5. > * The data mode is set to writeback > * barrier is set to 0, which, from what I understand, can also > compromise data consistency.
The NAS is going for maximum performance and never mind the integrity of the data. Could you remind us of the manufacturer. :-) > My understanding of these issues from what I read here > https://www.kernel.org/doc/html/latest/admin-guide/ext4.html#options > is that this effectively disables journaling, and seriously impacts > the reliability of the storage system (RAID 1). The journal will still be used, but in a way which makes recovery less robust. ext4(5) also describes the options and the defaults of ‘data=ordered,barrier=1,commit=5’ are much better. Certainly normal for a database's filesystem, or anything where data loss is to be minimised. And RAID 1 doesn't help because these options are all about the higher-level meaning of the data sent to the mirroring drives so assuming the RAID 1 does it's job then you've multiple reliable copies of incorrect data. :-) > Unfortunately, it is D-Link's scripts that mount the RAID array, so > I doubt that I can change the options. Look at ‘remount’ in mount(8). Not as part of binding, but standalone. With the right arguments you should be able to change the mount options to more sane ones soon after boot, with it ignoring /etc/fstab's settings. -- Cheers, Ralph. -- Next meeting: Online, Jitsi, Tuesday, 2020-09-01 20:00 Check to whom you are replying Meetings, mailing list, IRC, ... http://dorset.lug.org.uk New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
