So mine I used to have raid1 for boot, I gave up on that and simply put the boot disk on a non-raided SSD. I figure I can reinstall the OS easily and get the raid6 to work, I do have something copying critical config files into a directory in the raid6 to facilitate a rebuilt. So far I have done a clean reinstall of the OS disk 2-3 times and brought the raid6 across. I also have ,nofail on the fstab options for the raid6, this makes sure if the raid has an issue that the OS still boots to full multiuser mode and on the network so I can more easily login and fix whatever issue it was. My boot SSD is also 500GB as the stuff I have that writes all of the time write to that disk (motion/security cam software, and Mythtv recordings/DB). so that the raid6 can spin down most of the time. There is a nightly copy job that moves the data to the raid6. I write say 150GB/day to the ssd has 59% life remaining and has been used like this for around 3 years. On Sun, Apr 19, 2020 at 2:06 AM Alexander Shenkin <al@xxxxxxxxxxx> wrote: > > Hi all, > > I recently recovered my raid6 that had a problem during a reshape. My > system no longer boots, so I'm taking the opportunity to install a new, > clean OS. I have 7 disks with /boot mounted on a ~1.5 GB raid1 spread > across partitions on all disks, and / mounted on a 15TB raid6 with > partitions across all disks (~3 TB / disk). 11TB of that 15TB raid6 is > filled with data I'd prefer not to lose. I was going to use the same > layout to install ubuntu server 18, but partman is not able to mount the > raid6 for some reason (it thinks it's ext2, when it's ext4). > > I've gotten some feedback saying that it's not wise to use a huge raid > to mount at /, and that it might be better to mount the principal OS on > a separate mount point so that it can be formatted. I don't know if I'm > able to use LVM at this point, given that I have data I don't want to > lose on the raid6. It would be convenient to create another device at > this point so that I could format it and presumably get around partman's > inability to mount my raid6 at /... > > So, the question is, do you agree that it's better to separate out the > OS in another raid array or mount point? If so, is LVM an option at > this point, or should I somehow shrink the raid6 to make room for > another partition across all disks for another raid for the OS? > Finally, if so, (and perhaps this is beyond the scope of this list), > which root directories would you put where? > > Many thanks, > > Allie >
