From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brown Subject: Re: potentially lost largeish raid5 array.. Date: Fri, 23 Sep 2011 09:06:35 +0200 Message-ID: References: <201109221950.36910.tfjellstrom@shaw.ca> <201109222249.12892.tfjellstrom@shaw.ca> <20110923105834.71fc7c78@natsu> <201109222310.28684.tfjellstrom@shaw.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201109222310.28684.tfjellstrom@shaw.ca> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 23/09/2011 07:10, Thomas Fjellstrom wrote: > On September 22, 2011, Roman Mamedov wrote: >> On Thu, 22 Sep 2011 22:49:12 -0600 >> >> Thomas Fjellstrom wrote: >>> Now I guess the question is, how to get that last drive back in? would: >>> >>> mdadm --re-add /dev/md1 /dev/sdi >>> >>> work? >> >> It should, or at least it will not harm anything, but keep in mind that >> simply trying to continue using the array (raid5 with a largeish member >> count) on a flaky controller card is akin to playing with fire. > > Yeah, I think I won't be using the 3.0 kernel after tonight. At least the > older kernel's would just lock up the card and not cause md to boot the disks > one at a time. > > I /really really/ wish the driver for this card was more stable, but you deal > with what you've got (in my case a $100 2 port SAS/8 port SATA card). I've > been rather lucky so far it seems, I hope my luck keeps up long enough for > either the driver to stabilize, me to get a new card, or at the very least, to > get a third drive for my backup array, so if the main array does go down, I > have a recent daily sync. > My own (limited) experience with SAS is that you /don't/ get what you pay for. I had a SAS drive on a server (actually a firewall) as the server salesman had persuaded me that it was more reliable than SATA, and therefore a good choice for a critical machine. The SAS controller card died recently. I replaced it with two SATA drives connected directly to the motherboard, with md raid - much more reliable and much cheaper (and faster too).