From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcus Subject: Raid 5 Array Date: Sat, 2 Apr 2011 11:51:58 -0700 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids I have a raid array this is the second time an upgrade seems to have corrupted the array. I get the following message from dmesg when trying to mount the array [ 372.822199] RAID5 conf printout: [ 372.822202] --- rd:3 wd:3 [ 372.822208] disk 0, o:1, dev:md0 [ 372.822212] disk 1, o:1, dev:sdb1 [ 372.822216] disk 2, o:1, dev:sdc1 [ 372.822305] md2: detected capacity change from 0 to 1000210300928 [ 372.823206] md2: p1 [ 410.783871] EXT4-fs (md2): Couldn't mount because of unsupported optional features (3d1fc20) [ 412.401534] EXT4-fs (md2): Couldn't mount because of unsupported optional features (3d1fc20) I originally had a raid0 md0 with two 160GB drives, a raid0 md1 with 250GB and md0, a raid 5 with a 1.0TB, 500GB, and md1 I swapped out md1 with a new 1TB drive which worked. then i dropped the 500GB and combined it with the 250GB drive to make a 750GB drive The error seems to come when you reintroduce drives that were previously in a raid array into a new raid array. This is the second time I have ended up with the same problem. Any suggestions on how to recover from this or is my only option to reformat everything and start again?