A linux utility used to manage software RAID devices.

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6
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1answer
4k views

New md array is auto-read-only and has resync=PENDING

I've created a new md array with the following command: mdadm --create /dev/md1 -l 1 -n 2 /dev/sd[ed]1 But now /proc/mdstat shows the array as "auto-read-only" with resync=PENDING: ~ # cat ...
2
votes
1answer
573 views

Gentoo/mdadm: Remove 1 disk from RAID 0 array

The server has a 7-disk RAID 0 array, and sdf is starting to die. Is there a way to remove sdf while keeping the array intact? # df -h Filesystem Size Used Avail Use% Mounted on /dev/md1 14T ...
1
vote
1answer
257 views

mdadm + lvm2: destroyed all superblocks accidentally

I accidentally overwrote all my RAID1 superblocks with garbage. I think this happened because I ALT-CTRL-DEL booted when the Ubuntu had put me in some kind of hard disk recovery mode. My display ...
3
votes
1answer
292 views

mdadm; previously working; after “failure”, cannot join array due to disk size

Abstract I had a functional Raid 5 array, I rebooted the box, and then mdadm couldn't re-assamble one part. Seeing that it was only one part, I thought it would be easy to just re-sync. But that ...
3
votes
1answer
2k views

recovery data from RAID and disk failure (Linux)

Some background A friend of mine was using in his office a NAS Buffalo-LS-WVL with two disks of 1TB each. It seems that the two disks were mounted as raid 1, but, as you will read, probably they have ...
5
votes
2answers
412 views

RAID 5 with 4 disks fails to operate with one failed disk?

I found a question about mdadm spare disks which almost answers my question, but it isn't clear to me what is happening. We have a RAID5 set up with 4 disks - and all are labeled in normal operation ...
4
votes
4answers
2k views

Monitor disk health using smartd (in smartmontools) on a high availability software RAID 1 server

I have a server with three identical SATA/600 3TB drives: /dev/sda, /dev/sdb, /dev/sdc. The drives are partitioned, using GPT with three partitions each: 1 MB: Reserved partition for boot loader 1 ...
4
votes
3answers
762 views

mdadm with overlaying lvm - remove a hard drive

This is a hypothetical question, I'm just evaluating in which way I should configure my hard drives for my home-server and for that I need to know this: Let's say I have a Raid5 configured with mdadm ...
4
votes
2answers
2k views

What does mdadm's “spare” number mean?

I created a mdadm-based RAID 5 from six hard drives using the following command: # mdadm --create /dev/md0 --level=5 --raid-devices=5 \ /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1 \ ...
2
votes
2answers
299 views

Can I create a 2 TB RAID-1 array out of one 2 TB disk and two 1 TB disks while preserving 1 TB of data?

I currently have 1 TB of data on a RAID-1 mdadm array. This array consists of one 1 TB disk and a 1 TB partition on a 2 TB disk. I have now bought a second 1 TB disk, and I would like to use this to ...
4
votes
1answer
120 views

Reusing older raid discs

I have a software RAID5 array (Linux md) on 4 disks; the OS is OpenSUSE 12.3. Recently I replaced a disc with a larger one (fail disc, remove it, add new disc). The capacity of the array has not yet ...
1
vote
0answers
133 views

How to blacklist bad blocks from a MD-raid + dm-crypt + ext4?

I have a ext4 partition, on top of a dm-crypt, on top of a MD-RAID 10. One partition (/dev/sdc1) dropped out of the array with a ton of read errors. I ran the manufacturer provided diagnostic tool ...
1
vote
2answers
217 views

Can one use a md-type raid-0 as a drive for zfs pool

I want to play with ZFS at my CentOS. At the moment I have two 750Gb drives and two 400Gb spare drives that I could use. Of course the simplest solution would be to take all of them and use only 400Gb ...
1
vote
2answers
662 views

erased md0, md1 and can't recreate them

I previously had a working RAID 1 array. I think as a result of running grub-install /dev/sdb and grub-install /dev/sdc I somehow wiped my computer of md0 and md1. I need to set them up again. When ...
4
votes
1answer
568 views

How to boot after RAID failure (software RAID)?

Previously I had a software raid set up using (mdadm) of drives sda and sdb. sdb failed and the only way to reboot the system was by unplugging the second hard drive. Now I've added fresh sdb and sdc ...
1
vote
2answers
157 views

Raid5 Device Has Less Space Than Expected

I have 3 3TB drives, and have raid5ed them together. I would expect to get a resulting device around 6TB. The command I used: mdadm --create md0 --level=5 --raid-devices=3 /dev/sda1 /dev/sdb1 ...
0
votes
1answer
251 views

Using Grub2 to boot linux mdraid whole device RAID6

Linux mdraid supports device RAID (as opposed to partition RAID). The new superblock versions are also smart enough to not put the meta data right at the start of a disk. Does that mean it's possible ...
3
votes
1answer
3k views

No /etc/mdadm.conf in centos 6

I have installed centos 6 and setup a new RAID array with two disks. every thing is ok and I have partitioned the array but I don't see any /etc/mdadm.conf or /etc/mdadm/mdadm.conf files. I have ...
1
vote
1answer
198 views

missing files after reassemble of RAID-5

I had to open my file-server's housing today to replace a faulty fan. What I didn't see was that one of the sata-cables was not properly connected. The 1st thing I did after a reboot was a check of ...
3
votes
1answer
921 views

mdadm - Accidentally ran “mdadm --create” on an existing raid-1. The superblock is now corrupt and I am unable to recover data. Did I bork my data?

I have /dev/sdb1 and /dev/sdc2 that were previously setup into a RAID-1 with mdadm, but then I reinstalled and lost the old configuration. Out of idiocy, I ran sudo mdadm --create /dev/md0 --level=1 ...
4
votes
3answers
1k views

How to safely replace a not-yet-failed disk in a Linux RAID5 array?

I have a software RAID5 array (Linux md) on 4 disks. I would like to replace one of the disks with a new one, without putting the array in a degraded state, and if possible, online. How would that ...
1
vote
1answer
63 views

Can I put 2 disks into a raid-0 array without reformating the FS?

We have an existing /dev/sda disk, we are adding an identical /dev/sdb I want to place these two disks in a raid-0 array. Can I do that without reformating /dev/sda?
4
votes
3answers
2k views

lost superblock in md raid

Issue on Red Hat Linux 5. Due to some miscommunication two LUNs in our environment were enlarged from 1.2 TB to 1.7 TB. Now, after a reboot, mdadm does not find the superblocks to build the array ...
4
votes
2answers
5k views

How do I recover files from a single degraded mdadm raid1 drive? “not enough to start the array”

Given a single raid1 drive in degraded/rebuilding state, can it be force mounted? I'd like to recover all the files before undertaking the dangerous operation of pairing it and rebuilding. As far as ...
3
votes
2answers
4k views

Ubuntu: How do the md devices get assembled at bootup?

How do the md devices get assembled at bootup in Ubuntu? Is /etc/mdadm/mdadm.conf truly the relevant factor here? My mdadm.conf is sound and I checked that while I was in the rescue CD environment. ...
2
votes
0answers
359 views

Disable RAID auto detect at runtime

In Linux, I'm partitioning two disks for RAID1 with fdisk. The first disk partitioning succedes, but the second fail because the raid starts automatically and occupy also the second disk (why? it ...
2
votes
2answers
419 views

How does mdraid resync work?

I have two drives in a mirror (linux sw raid/mdadm); one drive somehow left the mirror in the past and its content is now several days old. At this moment, I'm using degraded mirror (with one drive ...
2
votes
2answers
1k views

Unable to rename a RAID device: stuck with /dev/md126

I had a fully working server. I booted with SystemRescueCD, without writing anything. I didn't even mounted a partition. Then rebooted the server. The server no longer boot correctly because some ...
2
votes
3answers
4k views

Can I create a software RAID 1 with one device

I have a single disk that I want to create a Mirror of, Lets call this disk sda I have just bought another identicle size disk, which we can call sdb. sda and sdb have one partition called sda1 and ...
9
votes
1answer
442 views

How do I recover a broken software RAID5 array?

Ack, I think I screwed up bad. I had a power failure on a RAID5 array which caused the metadata to be inconsistent between drives. I followed the advice here except a case of fat fingers caused me to ...
2
votes
1answer
193 views

Can MD cope with a badblock list?

I have a MD drive set in RAID6 configuration with LVM2 on top. One of my drives was faulted last night due to bad blocks. Now apart from the fact that I am aware I should physically replace the drive, ...
2
votes
1answer
743 views

convert /dev/md0 to /dev/sda1

I used a Software-RAID I and want to access the data without RAID now. After mdadm --fail /dev/md0 /dev/sda1 mdadm --remove /dev/md0 /dev/sda1 I tried mount -t ext4 /dev/sda1 /mnt but dmesg ...
4
votes
1answer
812 views

Unable to mount raid on my NAS, trying to rescue the data, how should I proceed?

A short backstory: something happened on my Synology NAS, apparently a buggy mailserver program that came with an update stopped the device from seeing the 2x3TB drives I have. After a lot of ...
2
votes
1answer
471 views

Ubuntu Software Raid5 - /dev devices changed, will mdadm raid break

I had a major server failure. The OS is fine and back up and running. Before I plug my raid drives back in and try and mount it I need to ask this simple question. The drives that originally mapped ...
2
votes
1answer
377 views

Recover MDADM Raid 5 in LVM with badblocks

I'm pretty sure I'm dealing with at stuffed RAID 5 array. Two of the drives were listed as failed in /proc/mdstat and mdadmdetails: 0 0 8 33 0 active sync /dev/sdc1 ...
3
votes
3answers
3k views

RAID5 recovery trying with “mdadm --create … missing”

First how I got in this situation: I had an RAID5 array with disks each 2TB (external USB-disks), I then wanted to create a larger encrypted array. Therefore I got 2 additional disks (also 2 TB each) ...
5
votes
2answers
3k views

/dev/md127 refuses to stop. No open files

So I'm trying to stop /dev/md127 on my Ubuntu 12.10 box. It was set up as RAID1, but I'm trying to move everything (well, rename) to md0. I read that renaming isn't possible, so I'm trying to remove ...
0
votes
0answers
52 views

Change numbers in the Number column to be consecutive from 0 for an mdadm RAID array

I have a RAID 1 array: # mdadm --detail /dev/md0 /dev/md0: Version : 1.2 Creation Time : Thu Oct 18 21:52:43 2012 Raid Level : raid1 Array Size : 1048564 (1024.16 MiB 1073.73 MB) ...
4
votes
1answer
6k views

Using UUID's with mdadm

I'm using GPT as my partitioning scheme. I check the UUID's of my partitions: # ls -l /dev/disk/by-partuuid/ total 0 lrwxrwxrwx 1 root root 10 Oct 18 22:39 0793009a-d460-4f3d-83f6-8103f8ba24e2 -> ...
3
votes
1answer
533 views

TrueCrypt is destoying mdadm volume

I'm setting up a new file server using the same storage configuration as my existing server, but the procedure is failing and i cannot figure out why. my goal is to create a TrueCrypt volume on top ...
13
votes
2answers
6k views

What's the difference between mdadm state “active” and state “clean”

I have two different computers with different RAID5 arrays. When I run the command mdadm --detail /dev/md0 one drive reports "active" while the other reports "clean" for the "state" field. What ...
1
vote
1answer
228 views

Issue with degraded raid5 after power outage

I have a raid5 that consists of 8 disks. After a power outage mdadm tells me that the raid is degraded. Here is the output: /dev/md0: Version : 0.90 Creation Time : Sat Jul 10 09:08:28 2010 ...
8
votes
2answers
889 views

What keeps one side of an rsync so busy?

I've got a Debian machine on my LAN serving as a backup server for the others. It has four HDDs combined into a software RAID 5 md device, on that an LVM, and on that btrfs. Backups are made using ...
4
votes
1answer
1k views

RAID 10 can not be started

I have a RAID 10 array managed with mdadm which has failed . The symptom was that X has crashed and I was unable to logon from the terminal. I have restarted the computer and /dev/md1 did not start. ...
9
votes
2answers
3k views

Grow/resize RAID when upgrading visible size of disks

I originally created a software RAID using a controller that could only address 2TB per disk. The disks are 3 TB disks. It worked fine, but only used the first 2TB of each disk. I have now changed ...
2
votes
3answers
653 views

Recovery of data on raid5+lvm reiserfs partition, after raid5 problems

I've got a server with 3 sata hard drives. Each has 2 partitions: one small is part of /dev/md0, a raid1 array (/boot), rest is part of a raid5 array (/dev/md1), which is an lvm physical volume. ...
2
votes
0answers
299 views

Software raid checksumming slow

On my new 24 disk array I get 900 MB/s of raw read or write using dd to all the disks. When I set the disks up as a 24 disk RAID6 I get 400 MB/s write and 600 MB/s read. It seems to be due to ...
1
vote
1answer
68 views

Is S25mdadm start script priority correct?

(On Ubuntu 11.10 - configuration inherited from 10.10) Occasionally the boot process seems to suffer a race condition where a starting process misses some of the Raid-1 FSes, build via mdadm. ...
15
votes
3answers
33k views

How to check mdadm raids while running?

I'm starting to get a collection of computers at home and to support them I have my "server" linux box running a raid array. Its currently mdadm raid1, going to raid5 once I have more drives (and ...
2
votes
2answers
9k views

MDADM - how to reassemble RAID-5 (reporting device or resource busy)

I rather new to the linux scene, and don't have nearly enough experience to actually consider myself somebody that can be trusted with using the system :P Anyhow long story short - I decided to use ...