On Sun, Nov 27, 2022 at 3:57 PM John Jason Jordan <[email protected]> wrote:
> On Sun, 27 Nov 2022 12:49:54 -0800 (PST) > Rich Shepard <[email protected]> dijo: > > >On Sun, 27 Nov 2022, John Jason Jordan wrote: > > > >> I've searched documentation on mdadm and I can't figure out if there > >> is a way to just restart the array. Suggestions? > > >How do I reactivate my MDADM RAID5 array? - Super User You should try > >stopping and re-starting the array: mdadm --stop /dev/md0 mdadm > >--assemble --scan to re-assemble the array and if that doesn't work, > >you may need to update your mdadm.conf, see for example this question > >for details on how to do that. Share Improve this answer Follow edited > >Mar 20, 2017 at 10:17 Community Bot 1 > > > >mdadm RAID array stop and restart - Ask Ubuntu https://askubuntu.com › > >questions › 1398907 › mdadm-raid-array-stop-and-restart Mar 23, > >2022Now to stop the array and restart it , I'm following below steps: > >mdadm --stop device mdadm --create ..... (the same command which I > >used to create the array at first) --- > Is it correct process to stop > >and restart RAID arrays? --- > Should I run "mdadm --zero ..." to > >clear superblock after stopping array ? Is it mandatory step to stop > >array? > > Rich, I found that AskUbuntu web page, but I note that the question > received no answers. In any event, stopping the array was a problem: > > sudo mdadm --stop /dev/md0 > mdadm: Cannot get exclusive access to /dev/md0:Perhaps a running > process, mounted filesystem or active volume group? > > The error message is hardly a surprise, since /dev/md0 was mounted - > sudo mount gave me dozens of lines, including: > /dev/md0p1 on /media/jjj/Movies type ext4 > > And then sudo umount /dev/md0p1 worked. But when I tried to remount it > I got: > sudo mount -a (it's in fstab) > mount: /media/jjj/Movies: can't read superblock on /dev/md0p1 > > So then I did 'sudo mdadm --stop /dev/md0,' which returned: > mdadm: stopped /dev/md0 > > And then I found a page that gave me the final solution: > > sudo mdadm -A -s > mdadm: /dev/md/0 has been started with 4 drives. > > Where -A = --assemble and -s = --scan, which scans for all arrays > located in /etc/mdadm/mdadm.config - checked earlier so I knew /dev/md0 > was in there with its UUID. I note that the documentation for --assemble > is confusing. Nowhere did I find anything that said its purpose is to > *restart* an already created array. I was afraid it would create a new > array. > > I could have continued with mounting it on the command line, but my GUI > file manager auto-mounts everything in 'Places' just by clicking on it, > so I clicked on it, et voilà!! I'm back in business! > > This array has been a pain for the past year and a half, so I'm going > to copy this whole discussion into my 'Commands.txt' file for future > reference. I still need to figure out why the array keeps failing, but > at least now I can recover somewhat gracefully. > > Thanks for poking me in the right direction! > So reassembling is what was needed, but you don't need to force it. Now if you just had some way to automate that. Have you connected your external enclosure to the UPS so that it is protected from temporary power disruptions? Bill
