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Questions tagged [mdadm]

A linux utility used to manage software RAID devices.

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How can I fix wrong mdadm.conf in a working raid 1?

I have a server linux with CentOS Linux release 7.9.2009. Server has 2 disks with a raid1 software. Raid1 seems ok, and if i run cat /proc/mdstat this is the output: Personalities : [raid1] md124 : ...
Castellino Roberto's user avatar
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Raid 5 replace with read errors

I have a software RAID 5 with 3 disks. For a few days, sda has been giving errors, and today the new disk arrived. I launched mdadm --replace and the process started correctly, but due to read errors ...
Gabriel Rolland's user avatar
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Trying to recover mdadm RAID1

I have a RAID1 array that I wanted to split into two individual drives. /dev/sdb and /dev/sdc were the two drives and there were three individual partitions. /dev/sd[bc]1 /dev/md0 /dev/sd[bc]2 /dev/...
Jpirok's user avatar
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Raid 1 (+0) reports as failed when one drive missing on the underlying raid 1

I have a somehow odd situation, we are trying to solve, but can't figure out. For one server we have a configuration like this: md0 : active raid0 md101[1] md100[0] 642050048 blocks super 1.2 ...
luison's user avatar
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Is it possible to setup mdadm raid1 on drive with running system?

Current system configuration is: nvme1n1 259:0 0 1.8T 0 disk nvme0n1 259:1 0 1.8T 0 disk ├─nvme0n1p1 259:2 0 1.1G 0 part /boot/efi ...
Michał's user avatar
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Troubleshooting slow write performance on hard drive

Issue I have 4 SSDs in a RAID0 array. I notice recently that when I am doing anything while on the array mountpoint I will run into these short glitches/pauses. For example, assume I am editing a file ...
Franz Kafka's user avatar
3 votes
2 answers
130 views

What is the risk of putting a RAID superblock at the end of a device?

I want to set up a RAID 1 array using mdadm to store backups (I'll be using rsnapshot to do the actual backups). I've read that using metadata 0.9 or 1.0 format with RAID 1 is advantageous because ...
jhaiduce's user avatar
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Raid10 Shows 5 Active Drives!

I built two raid 10 arrays during an Ubuntu 22.04 Server install, and the system works fine, but one of the two RAID 10 arrays shows all five drives (1 that should be a spare) in "Working" ...
bkeahl's user avatar
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mdadm raid drive missing after restart; parititions no longer show in fdisk/gparted

I'm in the process of creating a RAID 1 array with two 2TB disks. I was following the instructions for mdadm on the kernel wiki and successfully started the RAID process. sudo mdadm --create /dev/md/...
scuba_mike's user avatar
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Do SSD still need supercapacitor today ? (NAS : Linux + MDADM + EXT4)

I'm planning to build a SSD based NAS, with Linux / mdadm / EXT4 (so, no ZFS or Btrfs). What happens in case of a sudden power loss ? There are a lot of posts out there stating that we should buy SSDs ...
ChennyStar's user avatar
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Proper usage of linux mdraid spare-group

I'm going to create two raid1 arrays, lets say: 2x1tb - /dev/md1: /dev/sdb, /dev/sdc 2x2tb - /dev/md2: /dev/sdd, /dev/sde My idea is to use one additional 2tb hdd /dev/sdf as hot spare which will be ...
domino_pl's user avatar
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Recovery of failed RAID (RAID10)

I have a hosted server that was configured for RAID10. I didn't perform the original configuration, so I'm trying to handle the scenario delicately. Based on my inspection, they setup x3 RAID10 arrays ...
Malaxes's user avatar
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IMSM (Intel Matrix Storage Manager) device is not detected by Linux kernels 6.6.x/6.7.x but works in 5.19.17

In kernels 6.x.x /dev/md/imsm0 does not appear at boot. The only difference I see in dmesg which seems to be relevant: block device autoloading is deprecated and will be removed. Printed in 5.x.x, ...
midenok's user avatar
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Unable to format external SSD drive which was member of a raid

I try to reuse this drive as a single storage but if I zero it's super blocks then it restarts the md127 component. Tried everything like format from windows 7 with no avail...
user3018234's user avatar
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1 answer
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Reassembling MDADM on Live Ubuntu

Background: I have a 6x 4tb MDADM array on Box 1. Box 1 developed MB/CPU issues that cause a power-down halt about 15-25 minutes into operation, but during the uptime the array is accessible just fine....
Russell Anthony's user avatar
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162 views

Write speed to NVME disk degrade after some time of active work

I have a fairly general question, but maybe someone already had similar behavior. I have few servers with 20 nvme micron 7450 pro 15 TB disks on each. On all servers I created raid 0 using mdadm ...
igor_shk's user avatar
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Mdadm only able to assemble some of the drives from hardware array

After using ddrescue to back up the disks of a failing hardware RAID5 array (from a perc h700 controller) to images, and following Nikita's answer to my previous question to create overlays, I ...
arden opal's user avatar
1 vote
1 answer
159 views

LSI MegaRaid configuring for MDADM RAID disk set

I have an 8 bay SATA/SAS LSI MegaRAID controller and have to mount a set of drives that were assembled RAID 6 by mdadm on a non RAID controlled other device (both supermicro). Is it possible to ...
ChrisMinto's user avatar
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How to replace failed disk on Linux Raid (mdadm)

I get an input/output error when I list drives with: fdisk -l Failed to read extended partition table (offset=3886721022): Input/output error Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 ...
Leonardo Ramé's user avatar
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RAID 6, SSD Cache, Journaling, mdadm, LVM, Filesystem Strategies for Data Resiliance

I'm replacing a NAS server thats been in loyal service for almost a decade now. It will be repurposed as my offsite backup, but now I'm setting up a new NAS from scratch for homelab and need some ...
brianclements's user avatar
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2 answers
88 views

Raid 6 mdadm and 20 disk

Is it possible to add more than 2 disks for parity in mdadm raid 6? I need to build a storage of 20 disks. How to build a raid that would be reliable?
PetroIvanov's user avatar
1 vote
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282 views

mdadm RAID5 inactive and drive missing

I have a raid5 set up with mdadm and had to replace one broken hard drive. It worked for a while, but for some reason, became inactive after a couple of weeks. I'm pretty sure that the missing drive /...
lupus83's user avatar
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Trying to set up RAID 1 array on existing AlmaLinux OS disk running LVM, get 'partition exists' warning

I am following instructions from here for setting up a RAID1 on an existing Linux installation. The instructions are for a Debian/Ubuntu installation, but I can't find any specifically for AlmaLinux, ...
jamminjames's user avatar
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Mount raid1 drive failed, drive is busy or partition not found

I have the same issue as this question a few years ago mount: unknown filesystem type 'linux_raid_member'. I want to mount a drive coming from a raid 1 array. I followed the steps but mdadm --...
Yann's user avatar
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RAID1 drive vanished, but could be re-added after reboot. Should I be worried?

I am running Debian 12 with an MD RAID1 array (2 drives) for my personal data (no system files on array). Today I got a mail from mdadm about a DegradedArray event, during a time where my drives are ...
HighDraw's user avatar
2 votes
1 answer
584 views

Really slow FIO random 128 MB read values for a RAID 10 XFS

I've just installed two Samsung 970 EVO Plus drives, and configured the biggest partition as RAID 10 (far 2 layout). The problem is FIO only reports a read speed of 72 MB/s. I used the following ...
James's user avatar
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MDADM Chunk values

I've a RAID 10 array made up of two SSDs using mdadm on linux, I created it with mdadm --create --verbose --level=10 --metadata=1.2 --chunk=512 --raid-devices=2 --layout=f2 /dev/md/MyRAID10Array /dev/...
James's user avatar
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mdadm raid1 showing removed disk

I have a dedicated server which consists of two hard drives with 5 partitions each. NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS sda 8:0 0 1.8T 0 disk ├─sda1 8:1 0 1M 0 part ...
ProfGhost's user avatar
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How do I get my raid array back and mounted after reboot

I had created a raid-1 array for two drives (sde and sdf) using the normal mdadm process and had created it under md1 and mounted it to /mnt/storage. After a reboot md1 no longer exists. My /mnt/plex ...
Adam's user avatar
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3 answers
295 views

mdadm --zero-superblock for all devices of a mdraid?

I found no way to remove a mdraid from a server with one command. I can stop it via mdadm --stop /dev/md0 But the superblock is still in the devices. mdadm --zero-superblock DEVICE needs every device (...
guettli's user avatar
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Ubuntu 22.04.3 LTS running mdadm 16 x 8TB Raid 6 - Is it possible to upgrade individual disks and use the space immediately without using LVM?

Some more background... I have 4 realtime arrays (always running for me to use) - the 2 big important arrays (40TB [20TB used] and 112TB [105TB used] are being backed up onto a 16 x 8TB Raid6 array (...
PerryCS's user avatar
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Mdadm Raid5 kicking non-fresh drive from array

I set up a mdadm raid5 with 3 drives initially: sdc1, sdd1, sde1. They array creation was successful without issues. Later I decided to extend the array using one more drive. After proper partitioning,...
ricardo3889's user avatar
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mdadm copy superblock from drive to drive

i have an RAID5 consisting of 7 HDDS. One Drive is only partially accessable anymore. Unfortunatly i used the create command which resetted the superblocks of the 6 healthy drives. is there a way to ...
JJSCH's user avatar
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1 vote
1 answer
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Replacing a single SSD in 4 disk mixed software RAID 1 & RAID10 system

I'm about to replace a single SSD in a 4 SSD RAID 1 & RAID10 system. My webhoster will only do the drive replacement, but not help with adding it back to the array after. I've not done this before,...
Mr.Boon's user avatar
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setup Raid1 on running system

I have 2 disk sda and sdb with several partition. I have to make a raid1 of the running system. I managed to setup raid1 with md0 on root but there are 2 more partition which are mounted on /home and /...
codelearner1029's user avatar
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1 answer
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Reassign drive index number of mdadm software raid devices

My RAID 1 array has two disks as stated by # mdadm --detail /dev/md0 ... ... ... Number Major Minor RaidDevice State 5 8 32 0 active sync /dev/sdc 4 ...
razor7's user avatar
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1 answer
362 views

Convert MDADM RAID disk to non-raid disk

I have an existing RAID1 disk that is my boot & root drive locally. I want to convert this disk to a non-RAID disk and allow boot & root to be mounted without mdadm. What is the best way to ...
Derek Edwards's user avatar
1 vote
2 answers
367 views

Restore 4-Drive RAID5 array after accidentally reinitializing last 2-Drive as RAID0

I have an Asustor NAS with RAID 5 4-Drive running, after system update it reboot into the initialize page in web console, I think it's part of the upgrade process so I started the initialize progress, ...
Charles Chou's user avatar
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1 answer
127 views

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 ...
Aleksandr Dubinsky's user avatar
2 votes
1 answer
430 views

RAID arrays failed, now will not restart; mdadm --examine shows drive healthy but --assemble fails missing two disks

This is a Mint 21.1 x64 Linux system, which has over the years had disks added to RAID arrays until we now have one array of 10 3TB and one array of 5 6TB. Four HDs dropped out of the arrays, two from ...
tsc_chazz's user avatar
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/dev/md0 - wrong fs type, bad option, bad superblock on /dev/md0, missing codepage or helper program, or other error

I recently had issues with a raid filesystem I created and had some bad luck. I started creating a raid0 one one disk with the intent to expend it afterwards. I had data on two drives and had only one ...
noje89's user avatar
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1 answer
186 views

Temporary disconnect of HDD in RAID 0 array

I have a blade server on Rocky Linux 8 with 5 18TB WD Gold HDDs in a software RAID0 built with mdadm. I will accept all the lectures on this and change my ways if you all can help. I needed coffee ...
alchemist's user avatar
2 votes
0 answers
133 views

Transferring RAID1 to a new motherboard after HDD failure, and no "Superblock" found

First an OS SDD failure followed by a mobo failure, new mobo/cpu/ram later, and I have a RAID1 with a single working disk, and I am trying to get it remounted so that I can add in a new replacement ...
Aslan French's user avatar
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182 views

Raid6 mdadm reshape operation interrupted - now cannot mount or examine

Edit: Once the reshape finished the drive became fully accessible again. I had a power failure while a raid6 array was being reshaped, and now certain operations cannot be run against it, including ...
Jonathan Cremin's user avatar
1 vote
0 answers
122 views

Recreation of mdadm RAID backing store for drbd yields *The peer's disk size is too small!*

Some years ago, I've set up a storage cluster with stock Debian Linux using mdadm RAID as backing store by using the Debian provided drbd 0.8. Currently there are two RAID6 volumes, comprised of some ...
PoC's user avatar
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1 vote
1 answer
124 views

md Raid6 array disapeered on reboot

my raid6 array disappeared on reboot after I grew it. I believe the issue was growing 2x with the full disk not partition. It has been suggested a possible other reason the drives were not correctly ...
tjgrillz's user avatar
0 votes
1 answer
37 views

Removed failed disk from

I have a problem with a software raid running mirror. One disk is dead and the server cannot find it. Normally I would have removed it as well. mdadm --manage /dev/md0 --remove /dev/sda1 But after it ...
The Tech Guy's user avatar
1 vote
1 answer
1k views

Growing a RAID-10 on Synology NAS?

I was hoping to add two additional disks to my Synology NAS. Currently it is configured as a four disk RAID-10, no SHR, BTRFS, single volume system. Unfortunately extending a RAID-10 is not possible ...
TylerDurden's user avatar
-1 votes
1 answer
225 views

mdadm array state not fully active - faulty device

I use 4 drives as a raid 5 on my Raspberry Pi. I shutdown my Pi every night and start the next morning. Sometimes the array appears to be faulty. Maybe the Pi doesn't properly mounts the drives ...
RandomGuy's user avatar
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0 answers
151 views

Can I make hotremove/add on raid5 with mdadm?

I created and assembled software RAID5 array (mdadm), 15 SSD disks. If I physically remove several disks and add them back, RAID doesn't assembles back. Disks stays in "spare" mode. Even ...
sin4ez's user avatar
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