Re: LVM and raid
A couple of things i have set up for. The initital install is on LVM already so most of that was in place (including /) and i have no data on this. so if it wrecked its only an install away to start over. But this is a good start for some reading, thank you! On Thu, Jul 23, 2015 at 9:12 AM, Matt Graham wrote: > On 2015-07-21 13:28, Stephen Partington wrote: > >> Ubuntu 15.04 installed and am looking to find out if there is a way >> to migrate to raid on a running system. >> >> In theory i should be able to do this by creating a degraded portion >> of the raid volume on the empty disk, extend/move my LVM to that disk >> then rebuild the original disk as part of that raid volume. >> > > This is a softRAID-1, right? That makes the most sense for what you've > said. > > I was wondering if anyone had some documentation of information i >> could read about this scenario. >> > > I did something like this when I moved my stuff from just 1 disk on > regular partitions to softRAID-1. First, back up all your junk, because > there are multiple points in this where you could scribble all over your > disks. Second, make sure you have a LiveCD or LiveUSB disk to boot from if > the bootloader goes wonky. > https://wiki.gentoo.org/wiki/Complete_Handbook/Software_RAID should be > pretty applicable to working with softRAID and applicable to distros that > are not Gentoo. > > You'd first take the new disk and partition it. I would think you'd need > at least 2 partitions since having /boot on LVM is not going to work, and > possibly 3 because having / on LVM has more fiddly bits than having it on a > regular partition. > > So, fdisk /dev/sdb , set it up with 2 or 3 partitions (whichever), and > then set up the RAID. This'll assume that your largest partition (the one > that'll be your PV) is /dev/sdb2 . You'd then do > > mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb2 missing > > This'll set up an array in degraded mode on /dev/md0. You'd then pvcreate > /dev/md0 , then vgextend $VG_NAME /dev/md0 , then pvmove > /dev/$OLD_PV_LOCATION . Then vgreduce $VG_NAME /dev/$OLD_PV_LOCATION and > pvremove /dev/$OLD_PV_LOCATION to remove the old PV from lvm's config. > Then you'd add the old PV back to the md0 with mdadm /dev/md0 --add > /dev/$OLD_PV_LOCATION . The disk sync will probably take a while. > > You'll have to set things up so that the bootloader can figure everything > out. Are you going to put / on LVM? That requires that the initrd have > all the LVM tools on it. I don't know if Ubuntu can handle that > automatically or not--I would guess so, but ICBW. > > -- > Crow202 Blog: http://crow202.org/wordpress > There is no Darkness in Eternity > But only Light too dim for us to see. > --- > PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org > To subscribe, unsubscribe, or to change your mail settings: > http://lists.phxlinux.org/mailman/listinfo/plug-discuss > -- A mouse trap, placed on top of your alarm clock, will prevent you from rolling over and going back to sleep after you hit the snooze button. Stephen --- PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org To subscribe, unsubscribe, or to change your mail settings: http://lists.phxlinux.org/mailman/listinfo/plug-discuss
Re: LVM and raid
On 2015-07-21 13:28, Stephen Partington wrote: Ubuntu 15.04 installed and am looking to find out if there is a way to migrate to raid on a running system. In theory i should be able to do this by creating a degraded portion of the raid volume on the empty disk, extend/move my LVM to that disk then rebuild the original disk as part of that raid volume. This is a softRAID-1, right? That makes the most sense for what you've said. I was wondering if anyone had some documentation of information i could read about this scenario. I did something like this when I moved my stuff from just 1 disk on regular partitions to softRAID-1. First, back up all your junk, because there are multiple points in this where you could scribble all over your disks. Second, make sure you have a LiveCD or LiveUSB disk to boot from if the bootloader goes wonky. https://wiki.gentoo.org/wiki/Complete_Handbook/Software_RAID should be pretty applicable to working with softRAID and applicable to distros that are not Gentoo. You'd first take the new disk and partition it. I would think you'd need at least 2 partitions since having /boot on LVM is not going to work, and possibly 3 because having / on LVM has more fiddly bits than having it on a regular partition. So, fdisk /dev/sdb , set it up with 2 or 3 partitions (whichever), and then set up the RAID. This'll assume that your largest partition (the one that'll be your PV) is /dev/sdb2 . You'd then do mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb2 missing This'll set up an array in degraded mode on /dev/md0. You'd then pvcreate /dev/md0 , then vgextend $VG_NAME /dev/md0 , then pvmove /dev/$OLD_PV_LOCATION . Then vgreduce $VG_NAME /dev/$OLD_PV_LOCATION and pvremove /dev/$OLD_PV_LOCATION to remove the old PV from lvm's config. Then you'd add the old PV back to the md0 with mdadm /dev/md0 --add /dev/$OLD_PV_LOCATION . The disk sync will probably take a while. You'll have to set things up so that the bootloader can figure everything out. Are you going to put / on LVM? That requires that the initrd have all the LVM tools on it. I don't know if Ubuntu can handle that automatically or not--I would guess so, but ICBW. -- Crow202 Blog: http://crow202.org/wordpress There is no Darkness in Eternity But only Light too dim for us to see. --- PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org To subscribe, unsubscribe, or to change your mail settings: http://lists.phxlinux.org/mailman/listinfo/plug-discuss
LVM and raid
I am working on a home server running EFI. i have Ubuntu 15.04 installed and am looking to find out if there is a way to migrate to raid on a running system. In theory i should be able to do this by creating a degraded portion of the raid volume on the empty disk, extend/move my LVM to that disk then rebuild the original disk as part of that raid volume. I was wondering if anyone had some documentation of information i could read about this scenario. Added complication so far seems to be that this is a 2013 mac mini. Thanks in advance. -- A mouse trap, placed on top of your alarm clock, will prevent you from rolling over and going back to sleep after you hit the snooze button. Stephen --- PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org To subscribe, unsubscribe, or to change your mail settings: http://lists.phxlinux.org/mailman/listinfo/plug-discuss
