Server Fault Stack Exchange
Server Fault Stack Exchange

Questions tagged [mdadm]

A linux utility used to manage software RAID devices.

844 questions
4
votes
0 answers

How to correctly prevent auto-assembly of RAID arrays on Ubuntu 16.04?

I'm trying to stop mdadm from automatically assembling RAID arrays when I attach disks. I had a solution that worked on Ubuntu 14.04, but it doesn't work on 16.04. I've found a thing that works for 16.04, but it's a bit of a hack, so I'm hoping…
Giles Thomas
  • 203
  • 3
  • 11
4
votes
2 answers

Linux mdraid RAID 6, disks drop out randomly every few days

I have some servers that run Debian 8 with 8x800GB SSD configured as RAID6. All disks are connected to a LSI-3008 flashed to IT mode. In each server I also have a 2-disk pair as RAID1 for the OS. current state # dpkg -l|grep mdad ii mdadm …
junior_h
  • 41
  • 3
4
votes
3 answers

Is using nested RAID 6+1+0 a good idea?

Currently I have 24 disks of 500 GB, and I would like to create a bigger nested RAID using a Dell Power Edge R730 server, having 4 times RAID 6 with six times 500GB each, over them I want to add RAID 1, and RAID 0 on top overall. My question is: is…
Alin Andrei
  • 127
  • 9
4
votes
0 answers

Can't stop and reformat /dev/md0

I want to reformat /dev/md0, which is a RAID0 array consisting of 4 disks (sd[bcde]). However, when I tried to run the command mke2fs, I received the following error message: /dev/md0 is apparently in use by the system; will not make a filesystem…
roymaztang
  • 51
  • 3
4
votes
1 answer

NVMe drives write performance in software RAID 1

We have just received two brand new Supermicro servers 1028U-TN10RT+ with 10 NVMe slots, two of them with Intel DC P3600 800gb hard drives. We were eager to test the performance of the drives as the specification is promising very good read (up to…
markz
  • 173
  • 1
  • 4
4
votes
1 answer

Debian server has degraded mdadm array on every boot

I have a Debian server with MD raid (2 actives, one spare): Personalities : [raid1] md1 : active raid1 sdc2[0] sdb2[1] sda2[2](S) 1068224 blocks [2/2] [UU] md0 : active raid1 sdc1[2](S) sdb1[1] sda1[0] 487315584 blocks [2/2] [UU] …
Halfgaar
  • 8,084
  • 6
  • 45
  • 86
4
votes
2 answers

Where do md array definitions come from?

I created a md array in an ARM computer with two USB/SATA disks in RAID 1. Then I moved both disks to my Ubuntu desktop and installed mdadm. Installation detected the RAID and added the definition to /etc/mdadm/mdadm.conf. So, where did it come…
Oriol del Rio
  • 171
  • 3
4
votes
5 answers

mdadm 3-way RAID 1 - good solution for guaranteed 2-drive failure tolerance?

Is a 3-way RAID1 using mdadm a good solution to be able to sustain any two drives failing without the RAID failing? I know this costs extra in the sense of only being able to use 1/3 of the disk space (1 out of the 3 drives), but what about aside…
sa289
  • 1,318
  • 2
  • 18
  • 44
4
votes
1 answer

Best way to RAID 4 x Intel SSD 910 for PostgreSQL

I have a Linux (debian/ubuntu) server with 4 x Intel SSD 910 800GB pcie that I need to RAID together. The biggest problem with these card is that they give you 4x200GB drives that you cant hardware-raid (more about that here:…
Linus
  • 41
  • 2
4
votes
1 answer

Why is my HDD partition a character special device?

I have a bunch of old 1T disks with an mdadm array on them. They had been out of commission for awhile, but yesterday I slotted them into a server running an up to date Debian Jessie. Eventually I got the array back together, but two drives refused…
ACK_stoverflow
  • 184
  • 13
4
votes
1 answer

Unable to mount '/dev/sda'

My server has two 2 TB hard disk drives in soft RAID 1. I can't mount /dev/sda. Output of parted -l root@rescue:~# parted -l Model: ATA HGST HUS724020AL (scsi) Disk /dev/sda: 2000GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk…
Ram
  • 179
  • 1
  • 2
  • 8
4
votes
1 answer

CentOS 6.5 mdadm Raid 1 - Kernel Panic during raid data check

I have a brand new CentOS 6.5 install with two (mounted to /mnt/data) 1tb Western Digital Black drives in raid 1 with mdadm, configured via the installer. Unfortunately every now and again the entire system kernel panics with a trace similar to…
md_5
  • 386
  • 3
  • 11
4
votes
1 answer

RAID1 disks "forked", now duplicate

I have got a server hosted by OVH, which is configured to have a soft RAID1 array, /dev/md0, that holds a LVM PV. There is another /dev/md1 array, which was supposed to be the /boot, but which is finally not in use. This morning, I received from my…
Xowap
  • 41
  • 1
4
votes
1 answer

Very poor disk performance on KVM node - mdadm raid10

For a long period of time, i'm experiencing performance issues on CentOS servers that are used for KVM virtualization. I'm running software RAID-10 with 4 disks (Seagate ST2000DM001, 2TB, 7200rpm SATA-600) These KVM VM's are running off their own…
user208595
  • 41
  • 1
  • 3
4
votes
0 answers

mdadm error: found two disks with the number 0

Im running a server deep in the forest , and after a hard disco failure i got this error. error: found two disks with the number 0. It a server with 2, 1 TB disc in raid 1 with mdadm 0.9 SDA failed and mdadm swap to SDB, i change the hard drive,…
PsySkeletor
  • 181
  • 1
  • 13
1 2 3
…
56 57