From mboxrd@z Thu Jan 1 00:00:00 1970 From: Beolach Subject: Re: reshape raid5 to raid6 Date: Wed, 24 Jun 2009 06:17:20 -0600 Message-ID: References: <20090624102729.GY2828@rlogin.dk> <972c997a386db1106868b3dc6b29ee21.squirrel@neil.brown.name> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Wed, Jun 24, 2009 at 05:20, NeilBrown wrote: > > On Wed, June 24, 2009 8:27 pm, Michael Ole Olsen wrote: > > Is it possible to reshape my /dev/md0 raid5 into raid6? > > If you are are using Linux 2.6.30, then you can > > =C2=A0echo raid6 > /sys/block/md0/md/level > > and it will instantly be sort-of-raid6. > It is exactly like raid6 except that the Q blocks are all one > the one drive, and drive that previously didn't exist. > If you have a spare, it will start building the Q blocks > on that drive and when it finishes you will have true raid6 > redundancy, though possibly a little less than raid6 performance, > as a real raid6 has the Q block distributed. > > When mdadm-3.1 is released, you will be able to tell the raid6 > to re-stripe with a more traditional layout. =C2=A0This will take qui= te > a while, but you can continue to use the array (though a bit more > slowly) will it progresses. > Of course you don't need to do that step if you don't want to. If a raid5 is changed to raid6, and then the raid6 is grown w/ additional disks, will that switch it to a more traditional layout, since it has to be re-striped anyway? TIA, Conway S. Smith -- 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