From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Busby Subject: Re: Raid5 to another raid level?? Date: Fri, 2 Sep 2011 10:12:32 +0100 Message-ID: References: <-7094796685559591664@unknownmsgid> <20110902121959.173a1aa9@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20110902121959.173a1aa9@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: john.robinson@anonymous.org.uk, linux-raid@vger.kernel.org List-Id: linux-raid.ids Thanks Neil Is there anyway back from raid0 to raid4 as i know once at raid0 i will no longer be able to add any disks, in theory i could change echo raid0 > /sys/block/md0/md/level,but this would require adding a missing disk to the raid4 at the same time, not sure how easy that would be todo On 2 September 2011 03:19, NeilBrown wrote: > On Fri, 2 Sep 2011 01:54:49 +0100 Michael Busby > wrote: > >> As could not sleep, have just tested and works fine...here is what i= have done >> >> sdd and sde are the 2 new disks >> >> mdadm -C /dev/md1 -l4 -n3 -e 1.0 /dev/sdd /dev/sde missing >> >> not sure if worth now using 1.2 as this seems the default setting if >> not specified?? >> >> sdb and sdc are the old raid 5 disks >> >> echo frozen > /sys/block/md0/md/sync_action >> mdadm /dev/md0 --add /dev/sdb >> mdadm --grow --force /dev/md0 --raid-disks=3D4 >> >> echo frozen > /sys/block/md0/md/sync_action >> mdadm /dev/md0 --add /dev/sdc >> mdadm --grow --force /dev/md0 --raid-disks=3D5 > > You can do all this in one step - 3 to 5. > >> echo frozen > /sys/block/md0/md/sync_action >> mdadm /dev/md0 --add /dev/sdb >> mdadm /dev/md0 --add /dev/sdc >> mdadm --grow --force /dev/md0 --raid-disks=3D5 > > NeilBrown > > > >> >> echo raid0 > /sys/block/md0/md/level >> >> then resize the fs...job done :) >> >> >> >> On 2 September 2011 00:50, Michael Busby = wrote: >> > Will test tomorrow once back in the office, hope the 4tb sync will= be >> > finished by then >> > >> > I will report back my findings >> > >> > >> > >> > -- Sent from my HP TouchPadOn 1 Sep 2011 11:34 PM, >> > wrote: >> > On 01/09/2011 22:50, Michael Busby wrote: >> >> I have found the following and see that you can convert from raid= 4 to >> >> raid0 fairly easy >> >> >> >> >> >> http://ubuntuforums.org/showpost.php?p=3D10412231&postcount=3D20 >> >> >> >> i have a 2 disk raid5 and want to be able to convert this to raid= 0, i >> >> was thinking of adding a extra 2 disk and setting them up as raid= 0, >> >> moving the data over then adding the original raid5 disks to the = raid0 >> >> setup, but i see that you are unable to add disk to a raid0 setup= , >> >> would it be possible to setup a raid4 with 2 disks and 1 missing,= move >> >> the data from the raid5 to raid4 then add both of the original di= sks >> >> to the raid4 the downgrade this to raid0??? >> > >> > Off the top of my head, feeling slightly sozzled (been for a few b= eers), >> > this might work, but as your linked post referring to a list reply= from >> > Neil Brown says, you should test first. You could use some USB sti= cks, >> > or alternatively loopback devices are ideal for this kind of test. >> > >> > Cheers, >> > >> > John. >> > >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-raid= " in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at =A0http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html