From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pim Zandbergen Subject: freshly grown array shrinks after first reboot - major data loss Date: Thu, 01 Sep 2011 17:28:53 +0200 Message-ID: <4E5FA4B5.6010407@macroscoop.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids I replaced every 2TB drive of my 7-drive RAID-5 array with 3TB drives. After the last replacement I could grow the array from 12 TB to 18 TB using mdadm --grow /dev/md0 --size max That worked: md0: detected capacity change from 12002386771968 to 18003551059968 It worked for quite a while, until the machine had to be rebooted. It shrunk: md0: detected capacity change from 0 to 4809411526656 The LVM volume group on this array would not be activated until I repeated the mdadm command. It grew back to the original size. md0: detected capacity change from 4809411526656 to 18003551059968 However, this caused major data loss, as everything beyond the perceived 4.8 TB size was wiped by the sync process. This happened on Fedora 15, using kernel-2.6.38.6-27.fc15.x86_64 and mdadm-3.2.2-6.fc15.x86_64. The drives are Hitachi Deskstar 7K3000 HDS723030ALA640. The adapter is an LSI Logic SAS2008 PCI-Express Fusion-MPT SAS-2 [Falcon] (rev 03) (LSI SAS 9211-8i). I had to buy this adapter as my old SAS1068 based card would not support 3TB drives. I can probably fix this by creating a fresh new array and then start restoring my backups, but now is the time to seek for the cause of this. I can reproduce this on demand. I can grow the array again, and it will shrink immediately after the next reboot. What should I do to find the cause? Thanks, Pim