From mboxrd@z Thu Jan 1 00:00:00 1970 From: Piergiorgio Sartor Subject: Re: RAID-6 with 3 missing disks Date: Sun, 5 May 2013 10:43:34 +0200 Message-ID: <20130505084334.GA2304@lazy.lzy> References: <20130504160804.GA2242@lazy.lzy> <14872633-1367684555-cardhu_decombobulator_blackberry.rim.net-102434637-@b3.c7.bise7.blackberry> <20130504163006.GA3395@lazy.lzy> <20130505125827.1cb1e320@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20130505125827.1cb1e320@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: Piergiorgio Sartor , Rudy Zijlstra , linux-raid-owner@vger.kernel.org, linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi Neil, On Sun, May 05, 2013 at 12:58:27PM +1000, NeilBrown wrote: > On Sat, 4 May 2013 18:30:06 +0200 Piergiorgio Sartor > wrote: > > > Hi Rudy, > > > > thanks for the answer, but as mentioned at the end, > > "--force" assemby does not work. > > Reason is, 7 disks complains 3 are missing and the > > 3 missing are assembed, since their superblock does > > not report errors. > > Of course, 3 disks are not enough to assembly the > > array, forced or not. > > Details please. "--examine" output of every device would be a good start. > Output for "mdadm --assemble --force --verbose ....." > would help too. thanks for the answer. As mentioned in a sequent post, I fixed it by hex editing the superblock and restoring, in the 7 disks, the other 3 missing. Anyway, I did not considered the "--verbose" option, thanks for the hint. Thanks again, bye, pg > > NeilBrown > > > > > > bye, > > > > pg > > > > On Sat, May 04, 2013 at 04:22:39PM +0000, Rudy Zijlstra wrote: > > > Hi > > > > > > I would start with mdadm assemble --force > > > > > > Do not use create unless all else has failed > > > > > > Cheers > > > > > > Rudy > > > --- > > > Verstuurd met mijn BlackBerry van Vodafone > > > > > > -----Original Message----- > > > From: Piergiorgio Sartor > > > Sender: linux-raid-owner@vger.kernel.org > > > Date: Sat, 4 May 2013 18:08:04 > > > To: > > > Subject: RAID-6 with 3 missing disks > > > > > > Hi all, > > > > > > I know this was probably already discussed, but > > > maybe I need some refresh. > > > > > > I've a 10 HDDs RAID-6 which, due to mishap (disks > > > were disconnected accidentaly), has now 3 missing > > > devices and cannot be assembled. > > > The data should be OK, since no writes were occurring > > > during the accident, so putting them together again > > > should work. > > > > > > As far as I know, one option is to create, with > > > "mdadm -C" the array again, giving the disks in > > > the proper order. > > > > > > Since all HDDs are readable, I guess "mdadm -E" > > > should return the role of each device. > > > Is this correct for the creation order? > > > > > > Second question is about the "Data Offset", since > > > this array was created with an older version of > > > "mdadm" and the data offset is very close to the > > > superblock. > > > As far as I know, new mdadm creates the data a > > > bit far aways. > > > Is there any way to specifiy the proper offset? > > > > > > Finally, is there an alternative to "mdadm -C" > > > or it is the only option? > > > Forcing assembly does not work, but maybe there > > > is another way to tell mdadm to really assemby > > > the array, taking into account the superblock > > > information, which are all readable. > > > > > > Thanks a lot in advance, > > > > > > bye, > > > > > > -- > > > > > > piergiorgio > > > -- > > > 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 http://vger.kernel.org/majordomo-info.html > > > -- piergiorgio