Super User Stack Exchange
Super User Stack Exchange

Questions tagged [mdadm]

A linux utility used to manage software RAID devices.

309 questions
51
votes
8 answers

How can I make mdadm auto-assemble RAID after each boot?

I successfully created a RAID (mirroring) by utilizing mdadm. However, I must run the following commands after each boot: mdadm --stop --scan // to stop /dev/md127 - I don't know where the number 127 even comes from mdadm --assemble --scan // to…
BreakPhreak
  • 990
  • 4
  • 12
  • 19
34
votes
10 answers

How to get an inactive RAID device working again?

After booting, my RAID1 device (/dev/md_d0 *) sometimes goes in some funny state and I cannot mount it. * Originally I created /dev/md0 but it has somehow changed itself into /dev/md_d0. # mount /opt mount: wrong fs type, bad option, bad superblock…
Jonik
  • 5,700
  • 12
  • 46
  • 55
31
votes
3 answers

How do I reactivate my MDADM RAID5 array?

I've just moved house which involved dismantling my server and re-connecting it. Since doing so, one of my MDADM RAID5 arrays is appearing as inactive: root@mserver:/tmp# cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] [linear] [multipath]…
Jon Cage
  • 2,499
  • 11
  • 38
  • 47
30
votes
6 answers

Does RAID1 increase performance with Linux mdadm?

I have a cheap 2-bay NAS with a 2TB HDD. To be robust against disk failure, I'm thinking of buying a second 2TB HDD and putting it in RAID1 with Linux mdadm. The file system is ext4. Will this increase or decrease the performance of the NAS? What…
Jesse
  • 795
  • 2
  • 9
  • 16
29
votes
10 answers

Simple mdadm RAID 1 not activating spare

I had created two 2TB HDD partitions (/dev/sdb1 and /dev/sdc1) in a RAID 1 array called /dev/md0 using mdadm on Ubuntu 12.04 LTS Precise Pangolin. The command sudo mdadm --detail /dev/md0 used to indicate both drives as active sync. Then, for…
Deltik
  • 19,353
  • 17
  • 73
  • 114
28
votes
4 answers

How-to change the name of an MD device (mdadm)

Here is the output from mdadm -Esv: ARRAY /dev/md127 level=raid0 num-devices=2 UUID=d89d9d45:9a420812:c44c77eb:7ee19756 devices=/dev/sdb8,/dev/sda8 This is a v0.90 array. The question is as follows: how does mdadm assign the name for an…
XXL
  • 1,469
  • 4
  • 20
  • 34
15
votes
3 answers

How to force mdadm to stop RAID5 array?

I have /dev/md127 RAID5 array that consisted of four drives. I managed to hot remove them from the array and currently /dev/md127 does not have any drives: cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4]…
matt
  • 658
  • 1
  • 8
  • 16
13
votes
5 answers

Need to find which drives are mirrored within RAID-10 array

I have a home media server running on openSUSE 12.2. I'm using eight 2TB drives in a RAID-10 configuration. I deliberately bought two different types of drives: four Seagate Barracuda Green and four Western Digital Red. My goal is to configure…
CapnBFG
12
votes
7 answers

Adding drives to a RAID 10 Array

How would I grow a RAID10 array using mdadm? Obviously I would need to add 2 drives at a time, or would it have to be 4 drives? I have a feeling its just a bad idea. Or would be just wiser to just opt for RAID5?
stuartc
  • 545
  • 2
  • 5
  • 11
11
votes
2 answers

Resize underlying partitions in mdadm RAID1

I have a home built NAS, and I need to slightly reconfigure some of my drive usage. I have an mdadm RAID1 composed of two 3TB drives. Each drive has one ext3 partition that uses the entire drive. I need to shrink the ext3 partition on both…
kyork
  • 241
  • 1
  • 2
  • 5
11
votes
3 answers

mdadm RAID Fast Setup with Empty Drives?

I am recreating some RAID5 disks as RAID6 with mdadm. There is no data on the drives that I care about. Setting up RAID takes a while to setup the shape - I accept that when there there is data that needs to be striped and parity calculated,…
Paul
  • 59,223
  • 18
  • 147
  • 168
10
votes
2 answers

How does one enable --write-mostly with Linux RAID?

Unfortunately the mdadm and mdadm.conf man pages are not quite up to par. I would like to enable the --write-mostly flag for my RAID, but neither the man pages nor the internet will tell me how. I am not aware of any place to put default arguments…
user76871
  • 910
  • 9
  • 22
9
votes
3 answers

Can I use an entire drive for as a software raid member?

Can I use /dev/sda and /dev/sdb for my RADI1 configuration? Or do I first have to partition both with a single Linux raid partition?
Kaurin
  • 730
  • 5
  • 13
9
votes
2 answers

Btrfs on top of a mdadm raid10, or btrfs raid10 on bare devices?

I have a RAID10 managed by the mdadm and I have EXT4 filesystem on top of it. However, I like BTRFS and would like to convert the EXT4 filesystem to BTRFS, but I was thinking about performance and maintainability. For an example with BTRFS, I can't…
DejanLekic
  • 869
  • 3
  • 10
  • 24
9
votes
3 answers

Is it safe to put harddisks of a md-software-raid to standby?

I have a home-fileserver with 6 desktop harddisks in a md-raid. The server isn't accessed a lot, so I think it would be good for the harddrives to go in standby-mode after some idle time (e.g. with the hdparm -S or hd-idle command). Is this safe…
Dani31
  • 113
  • 1
  • 4
1
2 3
…
20 21