From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roberto Nunnari Subject: Re: replacing drives Date: Mon, 06 May 2013 13:30:35 +0200 Message-ID: <5187945B.2090207@supsi.ch> References: <517A8EB5.8080100@supsi.ch> <20130426155347.GA9928@cthulhu.home.robinhill.me.uk> <5183E592.6020409@supsi.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5183E592.6020409@supsi.ch> Sender: linux-raid-owner@vger.kernel.org To: Roberto Nunnari , "linux-raid@vger.kernel.org" List-Id: linux-raid.ids Roberto Nunnari wrote: > Robin Hill wrote: >> The safest option would be: >> - add in the new disks >> - partition to at least the same size as your existing partitions (they >> can be larger) >> - add the new partitions into the arrays (they'll go in as spares) >> - grow the arrays to 4 members (this avoids any loss of redundancy) >> - wait for the resync to complete >> - install grub/lilo/syslinux to the new disks >> - fail and remove the old disk partitions from the arrays >> - shrink the arrays back down to 2 members >> - remove the old disks >> >> Then, if you're keeping the same number of partitions but increasing the >> size: > > Ok.. got here. > >> - grow the arrays to fill the partitions >> - grow the filesystems to fill the arrays > > Now the scary part.. so.. here I believe I should give the following > commands: > > mdadm --grow /dev/md0 --size=max > mdadm --grow /dev/md1 --size=max > mdadm --grow /dev/md2 --size=max > > and after that > > fsck /dev/md0 > fsck /dev/md1 > fsck /dev/md2 > > and > > resize2fs /dev/md0 > resize2fs /dev/md1 > resize2fs /dev/md2 > > Correct? > > > .. I still have a couple of questions: > > 1) how do I know if there's a bitmap? > > 2) at present /dev/md2 usage is 100%.. could that cause any problem? > > 3) the new drives are 2TG drives.. As around one year ago had trouble on > linux (it was a server dated 2006 with CentOS 5) that would not handle > drives larger than 2TB.. I wander what happens if one day one drive > fails and the drive I'll buy to replace will be sold as 2TB but in > reality slightly larger than 2TB.. what will happen? Will linux fail > again to use a drive larger than 2TB? > At present I'm on ubuntu 10.04, all software from standard distribution. > > Pitfalls I should know? > > Thank you very much > Robi Anybody on this, please? I'd really appreciate some guidance, especially for these last steps. Thank you and best regards. Robi