Il giorno mar 23 apr 2019 alle ore 03:09 Peter Grandi <pg@xxxxxxxxxxxxxxxxxxxxxx> ha scritto: > 2TB is nowadays a pretty minuscule server (a number of people I > know have in their laptop one or two 2TB NVME drive...), but > then 100Mb/s is small in relation to that. Sure, but as wrote, this is a very old server, with very old hardware on a very old network that I can't change easily. Yes, a huge upgrade is planned, but that's impraticable in next few days. > Except that your situation is that you have 2x RAID1 sets each > with 2x 1TB disks, the first 2 disks have 4 partitions and each > partition is mirrored on the other disk. > > Since the two pairs of disks are independent, the obvious way to > proceed is to remove completely one of the two disk pairs, and > use the two slots thus freed to upgrade the RAID sets on the > first disk pair; then do the other. > > So for example, assuming that disk A1 is 'sda', disk 'B1' is > 'sdb', disk 'C1' is 'sdc', disk 'D1' is 'sdd', and you have > new disks A2, B2, C2, D2: > > * Remove C1 and D1. > * Put in their place A2 and B2. > * Expand A1 and B1 into A2 and B2. > * Remove A1 and B1, A2 and B2. > > * Put in their place C1 and D1, C2 and D2. > * Expand C1 and D1 into C2 and D2. > * Remove C1 and D1. > * Put in their place A2 and B2. > > To expand A1 and B1 into A2 and B2 (and similarly for the other > pair), the simplest and safest way is: > > * Make the RAID set on A1 and B1 read-only. > > * Configure A2 and B2 with the partitions you want. > > * Configure those partition pairs each as a RAID1, and format > each RAID1 set with the filesystems of choice, and mount them. > > * Copy using 'rsync -axAXHO' the data from the existing RAID > sets to the new RAID sets, e.g. from '/mnt/md-old[0-3]/' to > '/mnt/md-new[0-3]/'. The total size of all arrays is less than 2TB. So, you are probably right (if I understood properly) that I can use a single 2TB disk to hold all arrays (that would be a much better solution) So: - power off the server - remove 1 disks from each mirror - put one huge brand new disk - add some partitions to this disk - use these new partitions as replacement for the older ones stored on removed disks. - let the raid rebuild itself [1] - when rebuild is finished, start from scratch by replacing the other old disk [1] As wrote multiple times, i have to be 100% that nobody is changing the underlaying array during the whole operation, or the removed disk would be out-of-sync and useless in case of disaster Booting from a live image (which image do you suggest), without mounting the filesystem stored on the RAID, would be enough, right ? Is a brand-new mdadm able to handle properly a raid created on 2007? The newly synced array, would be usable by the 2007 mdadm when server boot up again?
