Questions tagged [md]
Multiple Device driver aka Linux Software RAID
80
questions
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1
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Cancel `md --grow` operation
I added drives to an md RAID5 array, and quickly realized that I forgot to create a partition as is best practice (something I’ve also learned from bitter experience). How can I cancel this operation ...
-1
votes
1
answer
58
views
How do I resize the filesystem on a RAID0 array?
My server consists of 2x512GB and 1x3.5TB disks.
root@bb2 ~ # lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
nvme0n1 259:0 0 476.9G 0 disk
├─nvme0n1p1 259:3 0 10.7G 0 part
│ └─...
- 99
2
votes
0
answers
55
views
Disk pair not usable after moving from hardware RAID (Windows) to software RAID (Linux)
A long time ago I created a RAID1 pair from the boot menu of a JMicron JMB363 card. All was working fine under Windows and the RAID1 array was recognized as a single disk. I don't remember exactly how ...
- 115
0
votes
0
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14
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System failure shortly after md raid growth and no md superblocks on added disks
tl;dr; I tried to grow my raid array by adding 2 10 tb disks to an exsistant 4x4TB raid 5 array, had a failure with the system disk (not part of the raid) shortly after the growth finished and after ...
- 101
14
votes
1
answer
2k
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When adding a new disk to RAID 1, why does it sync unused space?
I recently set up RAID 1 on Linux with mdadm. When adding a new HDD to RAID 1, data started to sync between my drives which is expected. I didn't expect that it started syncing the entire drive, ...
- 243
0
votes
1
answer
123
views
Why do md array rebuilds start?
I've recently made mdadm report about the events and yesterday I received a number of rebuild events. Why was the rebuild started? I don't see anything relevant in the journal. Also I'm concerned ...
- 2,065
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1
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35
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RAID is healthy but one device is unpartitioned - should I replace it?
I have a RAID5 array with 3 devices as follows:
~$ cat /proc/mdstat
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10]
md127 : active raid5 sdb[4] sdc1[2] sda1[3]
...
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0
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842
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sudo mdadm --assemble --run /dev/md0 /dev/sdc1 mdadm: /dev/sdc1 is busy - skipping
I am able to mount /dev/md0 device but not sdc1.
While mounting sdc1 getting below error.
sudo mount /dev/sdc1 /mnt/s1/
mount: /mnt/s1: unknown filesystem type 'linux_raid_member'.
janardha@saankhya-...
0
votes
0
answers
28
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recovering lost access to RAID5
I had perfectly working RAID5 and added another device.
I lost power during the RAID recovery. Now I have no access to it - it does not exist - lsblk does no longer recognize it as RAID5 - just ...
- 117
4
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1
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767
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Does Linux md-raid store backup metadata anywhere on the disk?
I know that with ext2/3/4 and other filesystems, copies of the superblock are stored throughout the disk in case the primary superblock is corrupted (https://ext4.wiki.kernel.org/index.php/...
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1
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2
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2k
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Recover BTRFS? bad magic on superblock on /dev/md2
so after a recent power outage my DS718+ RAID crashed.
After investigation with Syno Support we also identified that my RAM was broken (already removed) and as it was not a officially supported RAM ...
2
votes
1
answer
132
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How does Linux MD software RAID avoid assembling old and new devices into the same array?
On a Linux MD software RAID1 I removed a failed drive and added a new one. (All fine now.) The old drive and the new were never in the system at the same time.
Do I see that right, that adding the old ...
- 544
4
votes
1
answer
363
views
mdadm: power failure during raid1 rebuild
RAID1 array created with mdadm; array was rebuilding when there was a power failure. On coming back up, the array seems to be dead.
# cat /proc/mdstat
Personalities : [raid1]
md0 : inactive sdb1[2](S) ...
- 83
1
vote
0
answers
31
views
CentOS7 GPU cluster, expanding partition volume
I have a question. I'm trying to increase the disk partition to more than 50G, which I recall was the default given by CentOS7 during installation. I'm wondering how to go about doing so, since I have ...
- 11
2
votes
2
answers
598
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2 disk raid0, move all data to one disk, so the other can be removed
I have a raid0 md disk made up of 2 equalized disks. I would like to remove & replace one of the disks (with a disk of the same capacity), without losing any data. Since the md filesystem is only ...
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3
votes
1
answer
8k
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How do I make grub install on a software-raid disk?
I am running Debian 9 with mdadm RAID 1 on it. Previously both hard-drives could boot into the OS, now only one of them can.
I have recently had a faulty disk which needed to be replaced, so replace ...
- 363
1
vote
0
answers
177
views
Dismounting MD RAID1 LUKS-encrypted volume with partitions
Fedora 29. I created a 5TB RAID1 volume using mdadm. I then encrypted the volume with cryptsetup luksFormat. I then created ext4 partitions on the encrypted volume. (I did it this way so I can add ...
- 141
4
votes
1
answer
3k
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mdadm: Resume initial sync
I have a new md RAID10 that I created (on a Synology DS416slim, which is besides the point), which was in the process of initial sync:
root@ds416slim:~# cat /proc/mdstat
Personalities : [linear] [...
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6
votes
2
answers
3k
views
MD RAID - disable NCQ
Why is it recommended in a MD RAID (mdadm) to disable NCQ per-disk?
echo 1 > /sys/block/sdX/device/queue_depth
I read this tip in many articles regarding RAID tuning but nobody explains why.
- 101
1
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1
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212
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(Why) Does lvmraid6 need 5 drives?
I'm investigating using LVMRAID instead of MD+LVM. In my case, I'm looking at a RAID6.
As expected, the docs say you need N+1 devices for RAID5, and a minimum of 3 drives.
The docs say for RAID 6 ...
- 1,805
1
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1
answer
159
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How to pre-emptively repair/replace drive in linux md array without going degraded first?
I have (had, it's already been swapped out, asking this for future use) a drive that is indicating pending failure with internal SMART tests and bad block remaps.
It is straightforward to mdadm --...
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1
vote
1
answer
112
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Teaming a drive in multiple RAID groups [closed]
I've setup a home RAID for a friend in the past from a heap of old and new 2T and 3T drives. seems very much like what BeyondRAID does. I made a 7 member RAID5 group of the 2T volumes and the first ...
- 139
3
votes
1
answer
935
views
Data scrubbing and repairing a RAID1 mirror?
In Linux, if I have a software RAID1 mirror /dev/md1 with N ≥ 1 active devices, what are the semantics of the repair command?
echo "repair" >/sys/block/md1/md/sync_action
Am I correct to ...
- 159
1
vote
2
answers
2k
views
md raid fails to boot with missing drive
I got a server with Debian Jessie, 4 Drives sda to sdd all of which are partitioned likewise. The system is in a raid1 md raid over all drives. All drives do have grub and I can swap discs with each ...
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18
votes
3
answers
32k
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How to re-add a drive when RAID is in degraded mode?
I am running an unmanaged Ubuntu server and due to recent performance issue and sent a request to the provider only to receive the following response:
"Dear Client,
as requested we have checked ...
- 371
2
votes
1
answer
839
views
GPT, grub and mdadm. sda drive replaced, raid rebuilt in recovery mode, but now server won't boot
This is how partition table loooks like:
(parted) print
Model: ATA TOSHIBA DT01ACA2 (scsi)
Disk /dev/sda: 2000GB
Sector size (logical/...
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1
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1
answer
460
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How to keep md-raid from blocking IO?
I run a server with md-raid (software) level 1 (2 HDDs mirroring) and several different applications run on it.
The problem arises when file-intensive jobs (e.g. extracting large archives) run while ...
- 650
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votes
2
answers
1k
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Degraded md RAID5 won't boot
I'm running a Ubuntu server on a md RAID5. I started to have some issue with one disk, I received the following email from mdadm:
A DegradedArray event had been detected on md device /dev/md/0.
md0 : ...
- 55
0
votes
1
answer
796
views
raid0 (soft-RAID using Linux md drivers) hosting XFS: how to repair after replacing bad disk?
So the latest configuration of our Nova compute nodes are using raw /dev/sdX devices (no labels nor partitions) as components for an md0 (raid0) array on which they're hosting an XFS filesystem. When ...
- 807
2
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1
answer
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SSD fstrim on CentOS 6.x with software raid5
I have some CentOS 6.x servers. They have software raid1 and fstrim works well there.
On one of the servers, I decided to do software raid5 and ext4. I can mount it with discard and there is no error ...
- 804
2
votes
1
answer
767
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dracut-pre-trigger rd.md=0 removing md raid activation boot fails
The system is Fedora 22, recently upgraded from Fedora 21. The remaining kernel from Fedora 21 boots. The two kernels installed after the upgrade fail to boot.
The system is an Intel S-5000 PAL with 5 ...
- 141
0
votes
2
answers
84
views
Can I convert a single-disk system to software RAID1 without double-copying?
I have read this question: Can I create a "soft" RAID1 array without nuking data? as well as many other tutorials that layout this general process:
Create degraded RAID1 array on new drive
...
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0
votes
2
answers
439
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md raid10: how to make sure that replicated data is stored in right place?
When creating classic mirrored raids, it's usual to locate copies of data on disks of different kinds. In this case you would use a mix of disks of different series and manufacturers. That reduces the ...
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4
votes
1
answer
851
views
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[...
- 8,074
3
votes
1
answer
465
views
recover highly degraded raid array
I have a Linux RAID6 array (mdadm) composed of 8 disks.
2 disks failed. I replaced them, now I have 2 new empty disks.
I would like to rebuild the raid
but
when I start a raid rebuild, the rebuild ...
- 1,749
0
votes
0
answers
346
views
MD RAID Array Often Starts Without All Drives
I find that, when I start/restart my system, my MD array often doesn't start with all of the drives even though the device-names haven't changed at all.
I'll have to stop the array and reassemble it, ...
- 560
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votes
3
answers
1k
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In a software RAID1, why does tune2fs -c 0 /dev/sda1 not throw an error but change is not seen in tune2fs -l /dev/sda1?
The Title pretty much says it all.
Turn off mount count fsck seems to succeed:
tune2fs -c 0 /dev/sda1
tune2fs -c 1 /dev/md0
But listing out via
tune2fs -l /dev/sda1 shows mount count is set back to 1 ...
- 578
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1
answer
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Can RAID 6 support 3 or more parities? [closed]
It doesn't seem right to me that people are using RAID 1+0, RAID 5+0, or RAID 6+0 instead of using a RAID with 3 or more parities (akin to RAID 6) because the latter has a better reliability given the ...
- 358
4
votes
1
answer
547
views
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-...
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votes
2
answers
2k
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MD RAID sector repair
This article states that RAID controllers are smart about unrecoverable read errors, and try to rewrite such sectors with the redundancy of the component drives. If the sector is bad, the disk's ...
- 8,074
1
vote
1
answer
385
views
Force server to use all resources for resync
I need to resync my RAID and noticed that it isn't a big consumer.
I have booted my system with the Rescue CD and started the resync.
Looking at top it seems that the processes doesn't take much ...
- 243
1
vote
1
answer
2k
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Software-RAID with ext4 but without 64bit support
last year I set up a Software-RAID5 with 5x3TB yielding 12TB of usable capacity. Just today, needing more storage, I have finished growing the RAID to two more 3TB disks:
Personalities : [linear] [...
0
votes
1
answer
119
views
Raid1+0: create stripe over two /dev/mdx on partition or not?
Given that I haven't found a way to define how a Raid10 is created with mdadm, i went the Raid1+0 solution.
How to display/define Mirror/Stripping pairs with mdadm
mdadm --create /dev/md0 --level=1 -...
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1
vote
1
answer
1k
views
How to display/define Mirror/Stripping pairs with mdadm
I want to make a standard linux software Raid10 over 4 HDD. The server has 4HDDs, 2 pairs from different vendors in order to avoid batch problems.
I want to have the mirror over two different Vendors,...
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3
votes
2
answers
2k
views
md raid1 reading from one disk only
I have two identical HDD in a linux software raid 1. I observed a mostly reading load on this raid device, with the process showing mostly iowait. iotop shows about 75% disk utilisation overall.
If I ...
- 31
0
votes
1
answer
529
views
System wont boot from degraded RAID6
I have a Debian Wheezy with 3 Partitions as RAID6. MD0 is for Root and OS, MD1 is for SWAP and MD2 for Files. While copy files to MD2 the system reports kernel panic and halts. I have had shutdown on ...
- 11
5
votes
1
answer
623
views
reusing existing RAIDs on preseeded installation
I'm trying to automate the reinstallation process of existing Ubuntu installations.
Partition layout:
md0( raid1, /dev/sda1#/dev/sdb1 ) - swap (2G)
md1( raid1, /dev/sda2#/dev/sdb2 ) - / (20G)
md2( ...
- 51
0
votes
1
answer
224
views
Linux MD Raid same device detection
Linux md raid driver delays recovery/verification of multiple devices if they share the same parent device.
We have setup where disks are pationed via device mapper, they use bcache, etc.. and ...
- 600
1
vote
0
answers
813
views
SSD+MDRAID+LVM+KVM results in lower performance than expected
We use kvm for virtualization, the disk images are stored as logical volumes. The logical volumes are stored on a bunch of software-RAID1 (mdadm) arrays composed of Intel DCS3500 SSDs (each array is a ...
- 443
5
votes
2
answers
2k
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Boot failure with root on MD (RAID1) + LVM: udev event timing
A fresh install of Ubuntu Server 13.10 (x64) is having problems booting from its root volume located in md+lvm. I've kludged a solution for now, but I'd like to understand more about what's going on ...
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