From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roberto Nunnari Subject: Re: replacing drives Date: Tue, 30 Apr 2013 15:17:30 +0200 Message-ID: <517FC46A.1080702@supsi.ch> References: <517A8EB5.8080100@supsi.ch> <20130426155347.GA9928@cthulhu.home.robinhill.me.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130426155347.GA9928@cthulhu.home.robinhill.me.uk> Sender: linux-raid-owner@vger.kernel.org To: Roberto Nunnari , "linux-raid@vger.kernel.org" List-Id: linux-raid.ids Robin Hill wrote: > On Fri Apr 26, 2013 at 04:27:01PM +0200, Roberto Nunnari wrote: > >> Hi all. >> >> I'd like to replace two hd in raid1 with larger ones. >> >> I could just add the new drives in raid1 and mount it on /opt after a >> dump/restore, but I'd prefer to just have to drives instead of four.. >> less noise and less power consumption and noise. >> >> The question is: what whould be the best way to go? >> Tricks and tips? Drawbacks? Common errors? >> >> Any hint/advice welcome. >> Thank you. :-) >> >> >> present HD: two WD caviar green 500GB >> new HD: two WD caviar green 2TB >> > I don't think these have SCTERC configuration options, so you'll need to > make sure you increase the timeout in the storage stack to prevent read > timeouts from causing drives to be prematurely kicked out of the array. How do I increase that timeout? Also, the old HD are up and running for over 4 years now, and never got any trouble.. just time to time a few warning on /dev/sdb from smartctl: Device: /dev/sdb, ATA error count increased from 27 to 28 But I don't believe that's something to worry about.. > >> root@host1:~# uname -rms >> Linux 2.6.32-46-server x86_64 >> > That'll be too old for the hot-replacement functionality, but that > doesn't make much difference for RAID1 anyway. ok. > >> root@host1:~# cat /proc/mdstat >> Personalities : [linear] [raid1] [multipath] [raid0] [raid6] [raid5] >> [raid4] [raid10] >> md1 : active raid1 sda2[0] sdb2[1] >> 7812032 blocks [2/2] [UU] >> >> md2 : active raid1 sda3[0] sdb3[1] >> 431744960 blocks [2/2] [UU] >> >> md0 : active raid1 sda1[0] sdb1[1] >> 48827328 blocks [2/2] [UU] >> >> unused devices: >> > 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) got till here.. > - grow the arrays to 4 members (this avoids any loss of redundancy) now the next step.. that's a raid1 array.. is it possible to grow the arrays to 4 members? Thank you! Robi