At Thu, 2 Jul 2009 13:26:11 -0400 CentOS mailing list <centos at centos.org> wrote: > > Hi Bob, > > On Thu, Jul 2, 2009 at 13:18, Bob Hoffman<bob at bobhoffman.com> wrote: > >>If /dev/md1 is made out of /dev/sda2 and /dev/sdb2, it will not work, > >>as those partitions will still be the same size as they were before... > > > > The grow command is supposed to expand the size of that md1 from its current > > 200+GB to fill the rest of the 500gb drive. > > > > I thought you could then expand the lvm partions inside of that. > > I'm not talking about the logical volumes (that you called lvm > partitions), but the physical partitions that make /dev/md1, which are > /dev/sda2, /dev/sdb2 and /dev/sdc2. You're not really supposed to > change the sizes of those, so although you will have a 500GB disk, you > will still have a 250GB partition... > > Actually, it is indeed possible that you could fail a 250GB disk, add > a 500GB disk, create a larger partition on it and try to add it back > to /dev/md1, but I don't know if that will work or not, it might not > as the partitions are not exactly the same size, I never tried to do > something like that... If you want to try that, I suggest you have > good backups of your data before you start. According to the mdadm man page, a RAID1 set can be made from different sized disks/partitions. It will be sized the size of the smallest disk/partition in the set. Going through a series of fail/replace you could end up with a RAID1 set that is smaller than the smallest disk/partition, at which point the GROW option will grow the RAID1 set. And no, I have not done this. It also states that the kernel needs have the proper support to do this. > > The other situation (copying the partition table of the smaller disk > to the bigger disk and creating new partitions) is one that I already > used many times, and it always worked right for me. > > HTH, > Filipe > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > > -- Robert Heller -- 978-544-6933 Deepwoods Software -- Download the Model Railroad System http://www.deepsoft.com/ -- Binaries for Linux and MS-Windows heller at deepsoft.com -- http://www.deepsoft.com/ModelRailroadSystem/