On Fri, Mar 5, 2010 at 8:51 PM, Timothy D. Lenz <tlenz@xxxxxxxxxx> wrote: > > > On 3/5/2010 1:22 PM, Michael Evans wrote: >> >> On Fri, Mar 5, 2010 at 11:00 AM, Timothy D. Lenz<tlenz@xxxxxxxxxx> wrote: >>> >>> Current setup, 3 500gb sata drives, each with 3 partitions. >>> The first partition of each drive make up raid1 md0 boot and most >>> software >>> The next partition of each drive make up raid1 md1 swap >>> The 3rd partition of each drive make up raid5 md2 main data storage >>> >>> There is also a 40gb ide drive with 2 partitions, boot/software and swap. >>> It >>> was used for install and setup. But I never got boot changed over to md0. >>> So >>> currently md0 is not in use. md0 and md2 are mounted to folders on the >>> 40gb >>> so a precopy to md0 could be made before booting with a cd and copying >>> what >>> ever is left that needs coping. and to use md2. >>> >>> Current >>> # /etc/fstab: static file system information. >>> # >>> #<file system> <mount point> <type> <options> <dump> >>> <pass> >>> proc /proc proc defaults 0 0 >>> /dev/hda1 / ext3 defaults,errors=remount-ro 0 >>> 1 >>> /dev/hda5 none swap sw 0 0 >>> /dev/md0 /mnt/md0 ext3 defaults 0 0 >>> /dev/md2 /mnt/md2 ext3 defaults 0 0 >>> /dev/hdb /media/cdrom0 udf,iso9660 user,noauto 0 0 >>> /dev/fd0 /media/floppy0 auto rw,user,noauto 0 0 >>> >>> I want to change md0 and md1 from 3 drive mirriors to 2 drive mirrors. >>> >>> Finish changing over to booting from md0, move swap to md1 and move the >>> mount point for md2 to md0 >>> >>> Remove the the ide drive to free up space for the 4th 500gb drive. >>> >>> Copy md2 over to the new 500gb temparally. >>> >>> Get rid of the current md2 freeing up the 3rd drive since it was already >>> taken out of the mirrors above. >>> >>> Make a new md2 raid1 with the remaining space of the first 2 sata drives. >>> >>> Move the data from the 4th drive back to the new md2 >>> >>> Repartition the 3rd drive to 1 partition same as the 4th drive. >>> >>> Make raid1 md3 from the 3rd and 4th drives. >>> >>> It's the steps/commands to change md0 and md1 from 3 drive mirrors to 2 >>> drive mirrors that I'm not sure about. Though now looking at fstab I see >>> I >>> never even switched over the swap. So I guess, those to arrays would be >>> rebuilt. So it's more how to do that without messing with md2. >>> >>> The computer is still on grub1. I haven't updated it it. >>> >> >> So you have: >> >> [3-devices] >> Raid 1: Unused >> Raid 1: Unused >> Raid 5: Used - 3 disks >> >> [1-device] >> Boot + swap >> >> Just swapoff the raid-swap you want to re-create, then: >> mdadm -S /dev/md(swap) >> mdadm -S /dev/md(boot) >> mdadm --zero-superblock /dev/devices in those arrays >> >> Repartition those two areas of the disks as necessary. >> >> Create new boot and swap partitions. >> For boot make SURE you use either -e 0.90 OR -e 1.0 . Given the >> nature of /boot I'd say use -e 0.90 on it. >> For everything else, including swap use -e 1.1 and optionally >> write-intent bitmaps. >> >> At this point you should be able to move /boot and your swap off of >> the 40gb drive; just remember to re-install grub and that your BIOS >> likely sets the boot drive as bios-drive 0 regardless of which SDA/HDA >> linux sees it as. This is what the device.map file is used to tell >> grub. >> >> >> I lost exactly what you wanted the result to look like amid a long >> list of steps you /thought/ you needed to make to get there and >> references to md numbers that only have meaning to you. However it >> seems that you were mostly stuck getting to this point, so you might >> be able to determine a plan using the data you've yet to share with >> the rest of us with that 40gb drive out of the equation. >> >> Remember that you can't reshape raid10 yet, but you can start raid10 >> with 'missing' devices (and add in the spares later). >> > > can't make it much clearer, and I don't know where you got raid10 from. > > ARRAY /dev/md0 level=raid1 num-devices=3 > UUID=e4926be6:8d6f08e5:0ab6b006:621c4ec0 > ARRAY /dev/md1 level=raid1 num-devices=3 > UUID=eac96451:66efa3ab:0ab6b006:621c4ec0 > ARRAY /dev/md2 level=raid5 num-devices=3 > UUID=a7ed721e:04b10ab6:0ab6b006:621c4ec0 > > md 0 and 1 I want to change to 2 deivces. > Then get it booting from md0 which I think I know how to do as I got another > computer working that way. Then I can dump the ide drive making room for > another 500gb sata. It will be used to store the data from md2 while md2 is > remade from a 3 device raid5 to a 2 device raid1. This frees up a drive > giving me 2 500gb drives to make another 2 device raid1. Its the seperating > out 1 device from each of the current raid1's, md0 and md1 that I was asking > about. > That was concise enough to be worth reading through to get your desired result. I already told you how to do the safe portion of your last operation. Actually, I can see one benefit from two raid 1s over raid10; you could stripe them using LVM and for very little extra cost have a lot more flexibility. After you've followed my last email to get the system booting off your raid devices, you can replace the 40 with a 500, and then use the /new/ 500 to start a raid 1 with one device set as 'missing'. StartSlower but totally safe way: However what I'd do if I were you is get everything I could off of the 40gb drive; it would only take 10 DVDs at worse case; presuming it won't fit within ~500gb. 1) Duplicate all your data from the raid5 on to the single disk in a raid 1 + missing configuration. * you now have 1 copy with parity, and 1 copy waiting for mirroring. (two copies and some parity) 2) Fail one of the partitions from the raid5, --zero superblock it. * you now have 1 copy without parity, and 1 copy waiting for mirroring, and one free drive. (two copies) 3) --add the previous parity partition as part of the mirror set; IT MUST BE >= the size of the other partition in that mirror. * You have 1 copy without parity, 1 full copy being mirrored in to two copies. 4) WAIT for the mirroring operation to finish. 5) Optionally 'check' the mirror copy. * You now have 1 copy without parity, 1 fully mirrored copy (3 copies of your data) 6) With a fully safe copy of your data, and two partitions you can start a wider range of procedures. You could create two more raid 1 + missing arrays setup LVM with striping across them copy your data over in to one logical volume ++THEN AGAIN in to a second logical volume (Manually creating two copies of your data; this won't protect against drive failure but it will protect against individual failed sectors, which may be good enough.) Finally one at a time fail out members of the intact raid1 set and add them to the new raid 1s. Or probably proceed through other ideas; though none seems as appealing to me as what I just wrote; 4 drives isn't enough to seriously consider raid 5 or 6, and with the size of the drives you'd really be better off with going for raid 6, which is much slower and only slightly less risky than raid 1 + striping via LVM. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
