Hello, I've been too nervous to reboot, so I've left it in the rescue mode at the point where I assembled the raid arrays and went into boot at the \ partition. Tried to run: mdadm --stop /dev/md127 but got a mdadm: failed to stop array /dev/md127: Device or resource busy. Perhaps a running process, mounted filesustem or active volume group?
I tried unmounting /home which stretches onto this disk via LVM, but this made no difference. Any idea how I should proceed? Thanks, James On 5 July 2013 01:10, Bob Proulx <b...@proulx.com> wrote: > James Allsopp wrote: > > I'd like to hear about the optimisations, but I think I'll wait till I > get > > the system rebuilt! > > Basically I had expected you to use either rescue mode of the d-i or a > livecd or other to assemble the arrays. You did. But neither array > came up completely correct. One came up with one disk degraded. The > split brain clone came up on md127 instead of md0. The other one came > up on md126. So you should fix those using the discussed > instructions. I was thinking you would do that from the same system > boot that you had posted that information from. > > But your recent mail implies that you shut the system down and went > away for a while. So now it appears you need to "rescue" the system > again by the same method you used to get that information you posted. > > All of that is fine. Except now we already know the information you > posted. And so now we know how those arrays are supposed to go > together. But that is okay. You can go through rescue mode and > assemble the arrays exactly as you did before. And then --stop the > arrays and assemble them correctly. > > But since we know how they are supposed to be assembled now you could > skip the assembly of them in rescue mode or livecd mode or whatever > you used and simply assemble the arrays correctly the first time. > Basically I think you are going to do: > > * rescue > * assemble arrays > * stop arrays > * assemble arrays correctly > > Which is perfectly acceptable. The result will be fine. But now that > we know what we need to do you could simply do this: > > * rescue > * assemble arrays correctly > > But I don't want to distract you with complications like this! :-) > > And then after you get everything working you should visit the > partitioning on that second array. Your partitioning starts at the > sector 1. But that won't be aligned. It will cause all writes to be > a read-modify-write and performance will suffer. > > > Device Boot Start End Blocks Id System > > /dev/sdd1 1 243201 1953512001 fd Linux raid > autodetect > > Partition 1 does not start on physical sector boundary. > > Device Boot Start End Blocks Id System > > /dev/sde1 1 243201 1953512001 fd Linux raid > autodetect > > Partition 1 does not start on physical sector boundary. > > Instead of using the entire disk starting at 1 it would be much better > if you started at sector 2048 as is the new standard for Advanced > Format 4k sector drives. I would expect that to be a large > performance lever on your system. But fix that after you have your > data up and available. > > Bob >
