Tagged Questions

A linux utility used to manage software RAID devices.

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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
4k 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
53 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
7k 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
550 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
7k 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
239 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
945 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
682 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
312 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
70 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
38k 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 ...
5
votes
3answers
5k views

Using mdam --examine to write mdadm.conf

I'm trying to script the RAID setup for a (growing) number of identical servers. The advice I've seen for using mdadm suggests that once the RAID array has been created you can run mdadm --examine ...
3
votes
3answers
7k views

Grub2 RAID /boot

I'm using Gentoo on my HomeServer. My HDDs are raid1 mirrored with mdadm. My problem is how to boot the /boot partition correct? /dev/md1 consists of /dev/sdc2 & /dev/sdd2 mounted on /boot In ...
6
votes
6answers
3k views

Pros and cons of software Parity-RAID (e.g. RAID5)

I was recently told about some problems concerning Parity-RAIDs without a non-volatile cache. More exspensive HW-controllers do have battery-powered caches to finish write-operations in case of power ...
6
votes
1answer
11k views

mdadm raid1 and what chunksize (or blocksize) on 4k drives?

I want to use two 3 TB drives in a mdadm raid1 setup (using Debian Sequeeze). The drives use 4k hardware sectors instead of the traditional 512 byte ones. I am a bit confused because on the one hand ...
7
votes
1answer
2k views

mdadm Raid5 gives spares missing events

I succesfully builded up a raid5 array on debian testing (Wheezy). As the manpages and further tell, the array would be created as an out of sync array with just a new spare injected to be repaired. ...
9
votes
1answer
5k views

grub error “superfluous RAID member” on update-grub

My system (wheezy/sid: 2.6.32-5-amd64 #1 SMP x86_64 GNU/Linux) is running fine - I'm just wondering what some messages mean. I have two mdraid arrays running up on my system. Here's cat /proc/mdstat: ...
6
votes
2answers
2k views

Will the system make sure that mdadm is sync-ed before completing a reboot?

This is a follow up to my crazy mdadm problem. I'm trying to figure out what might have caused sda to get out of sync in the first place. The only thing I can think of is that I had just run a bunch ...
3
votes
1answer
1k views

installing grub 2 on mdadm, which device?

when installing grub(2) to mdadm devices are you supposed to install it to /dev/sdX or /dev/mdX?
2
votes
1answer
370 views

Drive was unable to assemble into the array

I ran mdadm -A /dev/md0 /dev/sda1 /dev/sdb1 Only /dev/sdb1 was loaded into the array though. I have a few more arrays on the same two drives too. Each time the partition on sda failed. dmesg told ...
4
votes
2answers
2k views

what is commit=0 for ext4? does mdadm not support it?

I see this in my dmesg log EXT4-fs (md1): re-mounted. Opts: commit=0 EXT4-fs (md2): re-mounted. Opts: commit=0 EXT4-fs (md3): re-mounted. Opts: commit=0 I think that means that dealloc is disabled? ...