<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body >Have you tried to re-add the drive?<div><br></div><div>mdadm --add /dev/sdc1 /dev/md0</div><div><br></div><div>Please recheck the syntax I'm on my phone. </div><div><br></div><div>Thanks. </div><br><br>-------- Original message --------<br>From: Mark Mitchell <mark.russel.mitchell@gmail.com> <br>Date:06/01/2014 18:15 (GMT-06:00) <br>To: tclug-list <tclug-list@mn-linux.org> <br>Subject: [tclug-list] This Software RAID newbie's array is missing a drive. <br><br>I built my first RAID array about a week ago, kinda vaguely<br>understanding what I'm doing. 4 3 TB drives in a RAID 5. It's been<br>working fine, and I've been slowly filling it up.<br><br>Took the machine apart today to upgrade case cooling and power supply.<br> When I brought it back up, I got this in the boot messages;<br><br>md/raid:md0: raid level 5 active with 3 out of 4 devices, algorithm 2<br><br>My 1st thought was that I didn't get everything hooked up (I had to<br>disconnect most of the drives to get the power connections on the<br>board), several reboots later, I'd confirmed that the system was<br>seeing all the drives;<br><br>root@debian:/var/log# lsblk<br>NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT<br>sda 8:0 0 931.5G 0 disk<br>├─sda1 8:1 0 14G 0 part /<br>├─sda2 8:2 0 37.3G 0 part [SWAP]<br>└─sda3 8:3 0 880.3G 0 part /home<br>sdb 8:16 0 2.7T 0 disk<br>└─sdb1 8:17 0 2.7T 0 part<br> └─md0 9:0 0 8.2T 0 raid5<br> └─md0p1 259:0 0 8.2T 0 md /srv/media<br>sdc 8:32 0 2.7T 0 disk<br>└─sdc1 8:33 0 2.7T 0 part<br>sdd 8:48 0 2.7T 0 disk<br>└─sdd1 8:49 0 2.7T 0 part<br> └─md0 9:0 0 8.2T 0 raid5<br> └─md0p1 259:0 0 8.2T 0 md /srv/media<br>sde 8:64 0 2.7T 0 disk<br>└─sde1 8:65 0 2.7T 0 part<br> └─md0 9:0 0 8.2T 0 raid5<br> └─md0p1 259:0 0 8.2T 0 md /srv/media<br>sr0 11:0 1 7.3G 0 rom<br><br>So, it looks like the partition on sdc isn't being seen as a raid<br>partition anymore.<br><br>FWIW;<br>root@debian:/var/log# cat /proc/mdstat<br>Personalities : [raid6] [raid5] [raid4]<br>md0 : active raid5 sdb1[0] sde1[4] sdd1[2]<br> 8790405120 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/3] [U_UU]<br> bitmap: 4/22 pages [16KB], 65536KB chunk<br><br>unused devices: <none><br><br>So, what's my next step? Looks to me like I need to recreate sdc1 as<br>a raid partition, then regrow the array. Is this correct?<br><br>In the meantime, I'm reading what I can and copying data off the<br>array. Nothing critical, but it'd be annoying to lose.<br><br>Let me know if I left out required information.<br><br>Thanks.<br>Mark<br>_______________________________________________<br>TCLUG Mailing List - Minneapolis/St. Paul, Minnesota<br>tclug-list@mn-linux.org<br>http://mailman.mn-linux.org/mailman/listinfo/tclug-list<br></body>