Questions tagged [mdadm]
a utility to administrate Linux Software RAID devices
500
questions
48
votes
1
answer
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I don't have a RAID but get the warning mdadm.conf defines no arrays
I installed 16.04 Server and I have had a similar message in my logs and this message when I upgrade initramfs packages through normal package upgrade.
...
Setting up initramfs-tools (0.122ubuntu8.3) ...
- 4,551
30
votes
6
answers
112k
views
How do I rename an mdadm raid array?
For some reason, when I try to rename an mdadm raid array to a textual name, the change doesn't take.
I tried the advice from this serverfault question, but to no avail.
~$ mdadm --version
mdadm - ...
- 1,089
29
votes
4
answers
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Why is my RAID /dev/md1 showing up as /dev/md126? Is mdadm.conf being ignored?
I created a RAID with:
sudo mdadm --create --verbose /dev/md1 --level=mirror --raid-devices=2 /dev/sdb1 /dev/sdc1
sudo mdadm --create --verbose /dev/md2 --level=mirror --raid-devices=2 /dev/sdb2 /dev/...
- 1,012
24
votes
5
answers
42k
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Can the EFI system partition be RAIDed?
I'm setting up a HTPC with Ubuntu 64-bit, using UEFI and RAID with GPT disks.
Is it possible for the EFI system partition (partition type 0xEF00) to be part of a RAID1 array using mdadm? I'm hoping ...
- 497
22
votes
4
answers
106k
views
How can I create one logical volume over two disks using LVM?
Hi. I've got a working Ubuntu 12.04 server, which is going to serve as media server. I've added two disks of size 3TB to put my data on, and I wish to combine these as one 6TB logical volume which I ...
- 323
21
votes
4
answers
67k
views
How do I align my partition table properly?
I am in the process of building my first RAID5 array. I've used mdadm to create the following set up:
root@bondigas:~# mdadm --detail /dev/md1
/dev/md1:
Version : 00.90
Creation Time : Wed ...
- 72.2k
19
votes
3
answers
57k
views
How to Install Ubuntu 14.04 with RAID 1 using desktop installer?
Many people claim that it is impossible to install Ubuntu onto RAID 1 with the Desktop CD. Is this really true? If not, how can it be done?
- 793
17
votes
2
answers
35k
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RAID (mdadm) - What happens if drives are mismatched in size?
Question 1 - Before you answer with "it just takes the smaller disk", hear me out quick. My 3TB WD Reds come out to be 3001 GB in size. Let's say I set up a mirror via mdadm for sdb1 and sdc1 which ...
- 557
17
votes
8
answers
15k
views
Making stripe_cache_size permanent
I did
echo 8192 > /sys/block/md0/md/stripe_cache_size
to improve my RAID performance, and it did helped alot.
But I still can't figure out how to make it permanent.
I was trying to set it in /...
- 519
16
votes
1
answer
50k
views
How to access MD RAID via Live CD?
We are currently trying to run access the data on a server running a HP Ml110 G5 SATA raid controller, using the latest Ubuntu Live CD. We need to delete a few files to let the server boot into ...
Neil
16
votes
1
answer
34k
views
Setting up RAID 1 on 14.04 with an existing drive
I have a currently installed Seagate ST3000DM001 (about 90% full) and a new Seagate ST3000DM001 (blank). I would like to setup RAID 1 without losing the data on my currently installed drive.
If I ...
- 165
16
votes
4
answers
13k
views
How to enable degraded RAID1 boot in 16.04LTS?
In previous ubuntu versions, adding BOOT_DEGRADED=true to /etc/initramfs-tools/conf.d/mdadm allowed the system to automatically boot when the root filesystem is on a degraded array. This no longer ...
- 161
15
votes
2
answers
49k
views
How to re-add accidentally removed hard drive in RAID5
I have a NAS on Ubuntu Server with 4 2TB hard drives in RAID 5. A couple of weeks ago, one of the hard drives died, but my RAID was working, although degraded. Luckily it was still under warranty and ...
- 171
14
votes
3
answers
38k
views
Put HDDs in standby after X minutes using hdparm doesn't work
I use Ubuntu 12.04 on a home server. There are 5 hard drives: one SSD with the OS and 4 HDDs (Samsung HD204UI) configured as a RAID5 using mdadm.
I don't need the RAID very often (say, about once per ...
- 951
14
votes
1
answer
120k
views
Software raid - mdadm - re-find my array
Description
Today I plugged in another hard drive and unplugged my raid drives to ensure when I wiped the drive, I would not accidentally pick the wrong drives.
Now that I have re-plugged in my ...
12
votes
4
answers
52k
views
Install Ubuntu 20.04 Focal Fossa with RAID 1 on two devices
I would like to install Ubuntu 20.04 Focal Fossa on a machine with two hard disks using RAID 1.
Unfortunately it seems this doesn't work. If I use the "Create Software RAID (md)" option and select ...
- 273
11
votes
1
answer
16k
views
How to Create Virtual Block Devices
I want to create multiple virtual block devices like /dev/sda and then use them to create an md device for test purpose.
I have mounted my root filesystem on /dev/sda1 and don't have extra space to ...
- 277
11
votes
1
answer
10k
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How do I repair my software RAID5 disks?
I accidentally unplugged my eSATA cable while rerouting some cables behind my desk and knocked my RAID array offline.
I believe the drives are fine, but they show up as state "removed" now, how can ...
- 72.2k
11
votes
1
answer
14k
views
How do you install Ubuntu on an Intel RST RAID-0?
I am attempting to install Ubuntu 16.04 to dual boot with Windows 10 on my new PC. I am using an MSI Z170A motherboard and two 512GB M.2 drives. My goal is to RAID-0 both drives, and split the single ...
- 111
10
votes
1
answer
29k
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How can I create a RAID array with >2TB disks?
I would like to know the correct way to set up a software RAID array on an existing server. I have two brand new 3TB disks to use for the array.
Specifically, I want to set up a 3TB RAID 1 array, ...
- 5,168
10
votes
1
answer
24k
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Switching mdadm to an external bitmap
I've just read this in another post about improving RAID5/6 write speeds:
After increasing stripe cache & switching to external bitmap, my speeds are 160 Mb/s writes, 260 Mb/s reads. :-D
I've ...
Oli♦
- 295k
9
votes
1
answer
30k
views
Unable to Mount RAID1 md0 - wrong fs type, bad option, bad superblock on /dev/md0, missing codepage or helper program, or other error
I've created a RAID 1 using mdadm as below however I am having problems mounting it...
sudo mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sdb /dev/sdc
mdadm: /dev/sdb appears to ...
- 191
9
votes
2
answers
5k
views
Do I have to worry about "error: superfluous RAID member"?
When running update-grub on the newly installed Ubuntu 12.04 with an older software RAID (md), I get:
error: superfluous RAID member (5 found).
error: superfluous RAID member (5 found).
Generating ...
- 5,722
8
votes
2
answers
30k
views
Improving mdadm RAID-6 write speed
I have a mdadm RAID-6 in my home server of 5x1Tb WD Green HDDs.
Read speed is more than enough - 268 Mb/s in dd.
But write speed is just 37.1 Mb/s.
(Both tested via dd on 48Gb file, RAM size is 1Gb, ...
- 519
8
votes
3
answers
100k
views
MDADM Superblock Recovery
After a power cycle I found my RAID 5 Array no longer working. I tried various methods to reassemble the array but nothing has worked so far. I believe I need to recreate the superblocks and UUIDs ...
- 299
8
votes
2
answers
8k
views
mdadm: breaks boot due to "is not ready yet or not present" error
This is so damn frustrating :-|
I've spent like 20 hours on this nice error, and seems like dozens of people over Internet too, and no clear solution yet.
I have non-system RAID-5 of 5 disks, and it'...
- 519
7
votes
3
answers
6k
views
How do I convert a RAID 4 array to RAID 0?
I had a three-disk RAID 0 array and ran the following to add a fourth disk:
mdadm --manage /dev/md127 --add /dev/xvdi
Each disk is a 1TB EC2 volume. The array took about 40 hours to reshape. About 1 ...
- 73
7
votes
2
answers
14k
views
Rebuild mdadm Raid5 after OS hard drive died
I have an ubuntu desktop 10.4 "server" with 5 hardrives. 1 of the hardrives had 3 OS's on it (Windows Vista, Windows XP, and Ubuntu 10.4). I primarily used the ubuntu OS so that I could use mdadm and ...
- 231
7
votes
2
answers
19k
views
update-grub install-grub - error: unknown filesystem
My root partition is /dev/md0, I changed the size of the partition and filesystem. Now when I run update-grub and install-grub it fails:
# grub-install /dev/sda
Installing for i386-pc platform.
grub-...
- 141
7
votes
1
answer
3k
views
mdadm raid 5 pairity check control / new behaviors in Ubuntu 20.04
It looks like there's been some changes in when mdadm does parity checks and how it is controlled. It used to start the first Sunday of the month at about 1AM and was started by a cron entry. Now it ...
- 491
7
votes
2
answers
29k
views
Can I cache an mdadm raid with an ssd?
I have a 1TB array set up in raid 1 using mdadm on Ubuntu 8, to store mission-critical files. I'd like to speed up read/write, especially for large files by caching to an SSD. Is this possible? Does ...
- 71
7
votes
1
answer
4k
views
MD + LUKS + LVM will not cleanly shutdown
My setup is currently raid1 + luks on each md partition and lvm on top to stripe between the arrays. There is only one volume group with one logical volume currently.
sdc ...
- 173
7
votes
2
answers
9k
views
Can I transfer my mdadm Software raid to a new system in case of hardware failure?
I have minimal experience with mdadm and software RAID, but I have a Dell Poweredge T110 II with two separate RAID 0 arrays, a total of two drives each array.
I'm anxious that the software setup won'...
- 337
7
votes
1
answer
9k
views
Is it safe to use UUIDs in fstab with a software RAID (mdadm)?
I'm running Ubuntu 14.04 on a system with three hard disks in a RAID 0 configuration. The setup of the RAID was essentially this:
mdadm --create --verbose /dev/md0 --level=0 --raid-devices=3 /dev/...
- 143
6
votes
2
answers
9k
views
Can I write data safely to a RAID-1 ARRAY while it is resyncing?
Will the files be in all drives on the array when the sync is complete?
What if a disk fails while sync is in progress?
- 63
6
votes
2
answers
16k
views
Is it possible to pause/abort mdadm reshape?
Saturday I added a new drive to my mdadm array, and the reshape process is taking a long time. Unfortunately there's a nasty storm coming, and I'm likely going to lose power, which will probably do ...
- 633
6
votes
1
answer
11k
views
mdadm warning (system unbootable) from update-initramfs, mkconf's suggested fix seems inconsistent with mdadm's description of problem
Summary: update-initramfs says system unbootable, message points to mkconf which suggests rewrite to mdadm.conf that would appear to break the RAID, system up (for now) but next reboot may kill it, ...
- 61
6
votes
1
answer
636
views
Ubuntu Core with Raid 1
I'm trying to set up my Nextcloud on a Raspberry Pi 3 on Ubuntu Core.
I want to have a Raid 1 setup, so a disk failure doesn't wipe out all the data (next to weekly backups I'll do with another disk ...
- 61
5
votes
3
answers
13k
views
System won't boot unless I type "exit" at initramfs prompt
I installed MDADM for my RAID, and ever since that when I boot up the system just sits at the purple screen forever. After pulling my hair out for a week, I finally discovered - purely by accident - ...
- 683
5
votes
1
answer
8k
views
Mdadm. Disk already part of an array
I am trying to delete my RAID array and start again because of some annoying error listing my gpt is corrupt. I used gparted to delete all the info off the disks, so they say "unallocated" on each ...
- 3,061
5
votes
2
answers
14k
views
Removing mdadm array and converting to regular disks while preserving data
I have a 6 disk (2TB each) mdadm RAID 5 volume created in Ubuntu 12.04 Server. However, I'm moving to a different solution and want to "unraid" my disks but keep the data. Only 50% is in use.
From ...
5
votes
2
answers
8k
views
“mdadm: Duplicate MD device names in conf file where found."
Problem:
When I boot my Ubuntu 16.04 (Server) box. I'm dropped to a Busybox V1.22.1 (initramfs) prompt I receive a message “mdadm: Duplicate MD device names in conf file where found.”
Good to know ...
- 91
5
votes
3
answers
23k
views
configure mdadm for existing intel rapid storage array
i have a raid 1 configured by intel rapid storage from the bios.
with windows i have an application which manage the raid.
i read about intel rapid storage for linux and found that the option is to ...
- 51
5
votes
1
answer
12k
views
How to determine device name for NMVe SSDs during install
I'm in the beginning of installing 16.04 Ubuntu flavor to rig. I'll use two NMVe SSDs in a RAID0 config. I have all of the commands lined up, I just miss one crucial bit: the actual device name of the ...
- 1,418
5
votes
2
answers
2k
views
How to migrate installed system to RAID1?
I have home server (Ubuntu Server 10.04) which boots from single 80Gb HDD drive, now I want to make it boot from 2x500Gb RAID-1. I've already successfully created it through MDADM.
But how can I move ...
- 519
5
votes
1
answer
4k
views
mdadm checking RAID 5 array after each restart
system info:
Ubuntu 20.04
Software raid 5 (added 3rd HDD and converted from raid 1).
FS is Ext4 over LUKS.
I saw a system slowdown after a restart, so I checked the array status via proc/mdstat, and ...
4
votes
1
answer
15k
views
remove mdadm raid1 without loosing data
I have 2 hdd's in raid1 using mdadm.
Now i want to completely disable raid but i want to keep data on disk 1, and use disk 2 separately
Is there a way to do this.
Ill be honest, i know what raid is,...
- 151
4
votes
2
answers
11k
views
Ubuntu Server 12.04, MDADM device number suddenly changes?
I'm facing a really annoying bug, I have set up a Software RAID1 with mdadm, and the setup went just ok with this results
/dev/md/lucas.mgscreativa.com.ar:0
I have also configured mdadm.conf like ...
- 1,569
4
votes
2
answers
5k
views
Reassemble Intel RST RAID on another mainboard
I Solved it
The solution is in my own answer (se my next post). This post only describes my original problem and what I've tried.
The may be some pointers in it for you though... or not.
I Solved ...
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4
votes
3
answers
7k
views
Raid array missing after reboot
While I see that there are multiple other questions that seem to be about the same (or similar) issue, none of them have a difinitive answer. Hence, I ask it again.
I am following the guide here (...
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