Questions tagged [mdadm]
A linux utility used to manage software RAID devices.
67
questions
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4
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explain md's raid10,f2
I know how most of the various RAID's work. But I stumbled on the recommended raid10,f2
mode while researching linux software raid. I don't really understand how it works on 2 or 3 disks. could ...
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votes
5
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Recover RAID 5 data after created new array instead of re-using
Folks please help - I am a newb with a major headache at hand (perfect storm situation).
I have a 3 1tb hdd on my ubuntu 11.04 configured as software raid 5. The data had been copied weekly onto ...
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26
votes
5
answers
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Best way to grow Linux software RAID 1 to RAID 10
mdadm does not seem to support growing an array from level 1 to level 10.
I have two disks in RAID 1. I want to add two new disks and convert the array to a four disk RAID 10 array.
My current ...
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55
votes
9
answers
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How to interrupt software raid resync?
I want to interrupt a running resync operation on a debian squeeze software raid. (This is the regular scheduled compare resync. The raid array is still clean in such a case. Do not confuse this with ...
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31
votes
5
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How do I move a Linux software RAID to a new machine?
I have a newly built machine with a fresh Gentoo Linux install and a software RAID 5 array from another machine (4 IDE disks connected to off-board PCI controllers). I've successfully moved the ...
- 3,362
15
votes
2
answers
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Unable to mount an XFS filesystem from Linux RAID6 array ("Log inconsistent")
First time poster - my apologies if I don't get the etiquette correct.
I have a ~200TB RAID6 array with 30 disks and I'm unable to mount it - I just get the message:
mount /dev/md125 /export/models
...
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18
votes
4
answers
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How to resize RAID1 array with mdadm?
I've running Ubuntu 11.04 (kernel 2.6.38-11). I replaced 2x160GB with 2x500GB drives. They are configured as RAID1.
The partition tables show the right sizes. Here's sfdisk:
# sfdisk -d /dev/sdb
# ...
- 213
14
votes
2
answers
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How to recover an mdadm array on Synology NAS with drive in "E" state?
Synology has a customized version the md driver and mdadm toolsets that adds a 'DriveError' flag to the rdev->flags structure in the kernel.
Net effect - if you are unfortunate enough to get a array ...
- 607
8
votes
1
answer
4k
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How do I troubleshoot my RAID array?
I just checked into my RAID array this morning and what I got is:
$ cat /proc/mdstat
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md1 : active raid1 sdc7[0]
...
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8
votes
4
answers
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apt-get update mdadm scary warnings
Just ran an apt-get update on one of my dedicated servers to be left with a relatively scary warning:
Processing triggers for initramfs-tools ...
update-initramfs: Generating /boot/initrd.img-2.6.26-...
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4
votes
1
answer
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Removing a device in "removed" state from Linux software RAID array
My workstation has two disks(/dev/sd[ab]), both with similar partitioning. /dev/sdb failed, and cat /proc/mdstat stopped showing the second sdb partition.
I ran mdadm --fail and mdadm --remove for ...
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4
votes
1
answer
9k
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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 ...
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3
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2
answers
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mdadm rebooted, array missing? can't assemble?
Not sure what is going on with my Array. I rebooted ubuntu 12.04.1 and got a error on startup that fstab couldn't mount the filesystem UUID I have for my mdadm array. After running a few commands a I ...
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5
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RAID-1 to RAID-5 using mdadm
As per subject.
When converting from RAID-1 to RAID-5 using mdadm, why must a RAID 1 array contain 2 devices and not more than 2 devices? I don't understand RAID strong enough to pinpoint a reason.
...
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10
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4
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write hole: which RAID levels are affected?
In my journey to understanding the advantages of RAIDZ, i came across the concept of write hole.
As this page explains, a write hole is the inconsistency you get among the disks of the array, when ...
- 336
10
votes
1
answer
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mdadm and 4k sectors (advanced format)
There are numerous questions on Serverfault about aligning 4k sectors disks, but one thing is not really clear to me yet.
I successfully aligned my RAID1+LVM. One of the things I did was use mdadm ...
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9
votes
1
answer
4k
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How to obtain read speeds of two disks using mdadm/btrfs raid1 or zfs mirror?
Given that RAID1 writes two copies of the data, my understanding is that reads should be close to twice that of a single disk.
I have tested read performance of different technologies (mdadm, zfs, ...
- 1,677
9
votes
2
answers
7k
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Rebuild mdadm RAID5 array with fewer disks
I have a 4 disk RAID5 array, one of which is starting to fail according to smartd. However, since I'm using less than half the space on /dev/md0, I'd like to rebuild the array without the failing disk....
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8
votes
3
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How to delete removed devices from a mdadm RAID1?
I had to replace two hard drives in my RAID1. After adding the two new partitions the old ones are still showing up as removed while the new ones are only added as spare. I've had no luck removing the ...
- 81
8
votes
1
answer
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How do I replace a disk marked as removed from a linux md raid-5 array?
I had some recent computer issues and somehow one of my disks ended up not being recognized in my array anymore. It identifies fine, and both smart and some other disk checking utils all say its fine, ...
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8
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4
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Using 4k drives with md/LVM/dm-crypt
I know that I have to align my 4k drives by a multiple of 8 sectors, but what about md-RAID / LVM / dm-crypt? How do I tell these layers that my drive is 4k? If they don't respect the 4k sector size, ...
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8
votes
1
answer
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Can I create a "soft" RAID1 array without nuking data?
I've just bought two 1.5TB disks with the aim of creating a 1.5TB RAID1 array.
In my infinite lack of wisdom (and a lack of space inside the computer - it already had 6 disks), I stuck one in, ...
- 1,819
7
votes
4
answers
8k
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Linux Software RAID1: How to boot after (physically) removing /dev/sda? (LVM, mdadm, Grub2)
A server set up with Debian 6.0/squeeze. During the squeeze installation, I configured the two 500GB SATA disks (/dev/sda and /dev/sdb) as a RAID1 (managed with mdadm). The RAID keeps a 500 GB LVM ...
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6
votes
4
answers
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How to recover raid? mount: can't read superblock
I had a raid5 array on /dev/md0 created with mdadm and it was working fine for about a year. It consisted of three HDDs of 1TB each. A few days ago there was a power failure and UPS failure. It was ...
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6
votes
4
answers
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How to create a software raid5 array without a spare
I am trying to create a software raid5 array using mdadm:
$ linux # mdadm --create --verbose /dev/md0 --level=5 --raid-devices=4 --spare-devices=0 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1
mdadm: ...
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6
votes
1
answer
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mdadm: drive replacement shows up as spare and refuses to sync
Prelude
I had the following devices in my /dev/md0 RAID 6: /dev/sd[abcdef]
The following drives were also present, unrelated to the RAID: /dev/sd[gh]
The following drives were part of a card reader ...
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6
votes
1
answer
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Cannot install grub, segmentation fault, unable to identify filesystem, superfluous RAID member, found two disks with same index — Debian 7
A server was recently transported from location A to B, a long journey that took six months. Things have gone wrong due to nothing being labeled prior to shipment. Yes, I know --- it was done by ...
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6
votes
2
answers
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Grub rescue, will not boot from mdadm RAID, no such disk or device -- mduuid wrong?
I am running a 14 disk RAID 6 on mdadm behind 2 LSI SAS2008's in JBOD mode (no HW raid) on Debian 7 in BIOS legacy mode.
Grub2 is dropping to a rescue shell complaining that "no such device" exists ...
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5
votes
1
answer
495
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3 drives fell out of Raid6 mdadm - rebuilding?
i had an mdadm raid6 array with 13x1TB drives. Within 10 minutes 3 of these drives fell out of the array... we assume bad cable to the controller card and replaced, however now we need to get the ...
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5
votes
2
answers
14k
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Linux RAID 1: How to make a secondary HD boot?
I have the following RAID 1 on a Centos 6.5 server:
# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdb1[3]
974713720 blocks super 1.0 [2/1] [_U]
bitmap: 7/8 pages [28KB], ...
- 1,229
5
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2
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How do I get mdadm to auto assemble my raid array?
After upgrading to Ubuntu 9.04, my raid 5 array is no longer being assembled correctly. Right now, from boot, it will start a raid array using ata-MAXTOR_STM3500630AS_9QG03T0L-part1, at /dev/md0, but ...
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1
answer
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mdadm: Growing a RAID0 Array Weirdness
I have created 3 RAID0 arrays using mdadm on 3 Rackspace CloudServers using Rackspace's CloudBlockStorage as their devices. Each array has their own set of CBS volumes. RS-CBS has an upper limit of ...
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4
votes
1
answer
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Growing a RAID5 using mdadm with multiple drives?
I have a RAID5 array that consists of 3, 2TB drives. I want to add 2 more drives. The tutorials involve adding a single drive to an array, such as this:
https://raid.wiki.kernel.org/index.php/Growing
...
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4
votes
3
answers
5k
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Can I convert a raid10 array to raid0?
I have created a raid10 array using mdadm. Metadata version is 1.2. I want to convert this to a raid0 array, is it possible?
P.S. I am having terabytes of data, I want to avoid copying the data over.
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5
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Can you disable automatic mdadm startup?
I am creating a RAID 10 array over four iSCSI targets. I want to control everything manually though so I can run it through heartbeat. I've unlinked the open-iscsi and mdadm scripts from /etc/rc#.d/ ...
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4
votes
3
answers
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mdadm: Disk configuration by UUID
I want to create a soft RAID-5 and use UUIDs im the mdadm config file. So I have four disks with 1 partition each that spans the whole disk. But since the partitons don'5 have a filesystem, blkid does ...
- 3,157
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votes
4
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Slow disk I/O in KVM with LVM and md raid5
I have been battling with a kvm setup under debian for two weeks now, specifically with guest I/O disk performance.
The system:
-Supermicro 1018d-73mtf (X10SL7-F motherboard)
-16GB ECC/UB
-Intel ...
- 41
3
votes
1
answer
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mdadm software RAID doesn't load at boot
I'm using mdadm to create a raid1 mirror across two disks. I can create my /dev/md5 array perfectly using the tools, but it does not automatically reload my /dev/md5 when I restart, I need to manually ...
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3
votes
1
answer
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Is there any way to build a linux software raid system without all drives?
I'm building a raid1 (ok it will probably be a raid10,f2 but the difference with 2 drives... isn't much) system with 2 1TB drives. However, 1 of the drives I've ordered is bad so I'm RMA-ing it. I'm ...
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3
votes
1
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Ubuntu 16.04 - frozen mdadm array
I had a working RAID5 array consisting of 6 4TB disks.
Smartd reported that one of the disks started failing.
I decided to do several things in one operation:
1) remove the failing disk
2) add new one ...
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3
votes
1
answer
5k
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How do I check if smartd and mdadm are running correctly?
I have a raid system on debian:
Disk /dev/sda: 320.1 GB,...
Device Boot Start End Blocks Id System
/dev/sda1 * 1 2432 19535008+ fd Linux raid ...
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3
votes
2
answers
3k
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Odd mdadm output: --examine shows array state failed, --detail shows everything clean
The setup: 8 disks in a mdadm-managed RAID5 array (/dev/md0, made from /dev/sdc through /dev/sdj). One disk (/dev/sdh) is showing SMART errors (increasing pending sector count) so I'm looking to ...
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2
answers
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mdadm - RAIDs of partitions or partitions of RAID?
If using entire drives for an mdadm RAID which will be the boot device as well, is it more correct / standard to:
1) Configure the RAID out of partitions that encompass the whole drive (like /dev/...
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votes
2
answers
2k
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mdadm did not notice a failed disk in raid0
I have a server with mdadm raid0:
# mdadm --version
mdadm - v3.1.4 - 31st August 2010
# uname -a
Linux orkan 2.6.32-5-amd64 #1 SMP Sun Sep 23 10:07:46 UTC 2012 x86_64 GNU/Linux
One of the disk has ...
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votes
3
answers
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Hard disk / SSDs - detection and handling of errors - is silent data corruption reliably prevented?
When an error occurs on a drive, is it correct to assume that it will always be detected and reported to the OS (if software RAID such as mdadm) or RAID controller (if hardware RAID) as a failed read (...
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2
votes
3
answers
3k
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Creating a partitioned raid1 array for booting a debian squeeze system
I'd like to have the following raid1 (mirror) setup:
/dev/md0 consists of /dev/sda and /dev/sdb
I created this raid1 device using
mdadm --create --verbose /dev/md0 --auto=yes --level=1 --raid-...
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2
votes
2
answers
10k
views
Linux- Convert 2 disk raid1 to raid0
I have a linux server (3.19.0) which has raid setup with md (v3.2.5). / is a raid1 device with 2 disks. There was a mistake when installing this machine, instead we need those 2 disks to be in raid0 ...
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2
votes
4
answers
5k
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mdadm assembles with drives instead of partitions
I have a RAID 5 array built from partitions on 5 drives - /dev/sda1, /dev/sdb1, /dev/sdc1, /dev/sdd1, and /dev/sde1. When I assemble the array manually, it works fine.
Unfortunately, there seem to ...
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votes
2
answers
1k
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mdadm fail, disk won't show up
One of my disks failed in my raid array:
cat /proc/mdstat:
Personalities : [raid1]
md1 : active raid1 sda2[2](F) sdb2[1]
488086720 blocks [2/1] [_U]
md0 : active raid1 sda1[0] sdb1[1]
...
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2
votes
0
answers
998
views
mdadm: failed to set writable for /dev/md126: Device or resource busy
yesterday my one of SSDs on my server came into a faulty state. Well at least mdadm --detail /dev/md126 said that. Also mdstat showed [2/1] [_U] on one of raid partitions (md126 specifically). I ...
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