Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [mdadm]

A linux utility used to manage software RAID devices.

1
vote
0answers
20 views

Disk utilization on mdadm raid 5 is 100% even though none of the member disks is at 100%

I am currently confused about the disk utilisation of one of my machines. The setup: I have a machine containing 4 2TB HDDs. For those HDDs I used mdadm to configure a RAID 5 (called md2) On MD2, I ...
0
votes
0answers
16 views

MDADM can't automount existing RAID1 array

I recently reformatted my system and cannot get my RAID 1 array to load on boot. Would appreciate some help figuring out why this is. Using ubuntu 14 with MDADM. Its a very simple RAID1 array ...
-1
votes
1answer
39 views

mdadm RAID 1 partitions on sda1 and sdb1

Quick background: I have a RAID 1 array, created using mdadm. Both drives are hard-drives. The RAID array is called md127. There are 3 partitions in this RAID array: 20G for /var, 20G for /opt and 891....
2
votes
0answers
47 views

Reducing disks from a RAID5 mdadm with LVM

Checking a system, I found a server with 12 4TB drives in Raid5, with LVM on top. Single VG, single PV, and a few LGs that wouldn't need more than 6TB of space (currently only 4TB). Read speed is no ...
1
vote
1answer
43 views

Why isn't a disconnected and then reconnected mdadm RAID1 disk automatically re-attached and re-sync?

I'm doing the following test with Debian 9 under Hyper-V: I have two (virtual) disks, each with one partition, and /dev/md0 defined as RAID1 of /dev/sda1 and /dev/sdb1. The root EXT4 file system ...
0
votes
0answers
14 views

ix2-dl soho software won't mount disks

TL;DR the web gui and event viewer as well as soho.log don't actually print when mounting disks. It mounted itself eventually after a few days of uptime. No log message, no warnings or errors. No idea ...
0
votes
1answer
111 views

Debian mdadm: No devices listed in conf file were found

My Debian sid machine had been booting kernel 4.13 from a raid array for several months without issue. 2 days ago I upgraded the platform and now booting fails like this: Additionally, the initramfs ...
0
votes
1answer
211 views

SW RAID-1 grub-install

I just changed /sda system disk in SW RAID using following steps, simply put: sfdisk -d /dev/sdb | sfdisk /dev/sda mdadm --manage /dev/md0 --add /dev/sda2 Now disk is initializing chcked by: cat /...
2
votes
0answers
43 views

mdadm - are there any downsides of mixing 512 B and 4 kB logical sector size disks in RAID 1 or RAID 5/6?

I have a mdadm RAID 1 and RAID 6 setup with 8 TB disks which are using 4 kB physical sector size but 512 B logical sector size. I want to add more 8 TB disks to these arrays and the way I usually do ...
3
votes
2answers
67 views

Persistence of home directory after deleting all partitions and reinstalling:

I was running Ubuntu Server on a mdadm RAID1 volume, and I ran into some problems so I decided to just do a clean install. I booted with Gparted, stopped the mdadm array, and ran --zero-superblock ...
1
vote
2answers
99 views

USB hard drive I/O slow speeds

I have several Mediasonic ProBox HF2-SU3S2 with 4 drives - all with the same symptoms - extremely slow I/O (at best, about 10MB/s write). Each unit is configured with a software RAID 5 using mdadm ...
0
votes
0answers
73 views

Coping with bad sectors on RAID disk

I have a RAID 1 of 2 hard drives managed with mdadm. Today, one of them failed. I figured out that this is because of bad sectors in /dev/sdb. According to badblocks, these sectors are affected: 1028, ...
0
votes
0answers
25 views

Cannot add partition back to RAID 1

I run an mdadm RAID 1 on my Raspberry Pi. The USB cables to the two hard disks (especially to /dev/sda) seem to provide somewhat loose connections or someone touches them. They are right next to the ...
1
vote
0answers
34 views

HDD works with onboard SATA connectors but not behind LSI 9201-16e. Why is that? [closed]

I'm trying to build a NAS from scrap hardware I had laying around. It's current specs are: Motherboard: P5N32-E SLI Plus (latest bios as of writing) RAM: 3 GB generic DDR2 OS Storage: 80 GB Maxtor ...
2
votes
3answers
681 views

BTRFS Raid 1 vs. MDADM Raid 1

I'm currently in the process of setting up a NAS system mainly for backing up my computer and probably also for streaming media files to my devices. For these purposes, I decided to use ...
1
vote
1answer
28 views

Raid with faulty spare reference but with all physical devices good

I'm seeing sdt[6](F) but I cant remove or set it as failed device # mdadm /dev/md126 --fail /dev/sdt --remove /dev/sdt mdadm: cannot find /dev/sdt: No such file or directory /dev/sdt does not exist ...
1
vote
0answers
58 views

recover data from former RAID 1 drive

I had a RAID1 setup (md0), mirroring two 2TB drives (sdb, sdc). When trying to remove the RAID to use the disks individually with the data on them, I ran mdadm --stop /dev/md0 mdadm --zero-superblock ...
0
votes
1answer
83 views

How to set timeout for the systemd start job “dev-md125.device” (mdadm)

I've setup a RAID1 device with mdadm on CentOS 7. The system boots fine when both disks are inserted but hangs when there is only one. The error occurs at boot with the following message from systemd:...
1
vote
1answer
331 views

Add linux md raid write journal to and existing array

I have a raid5 array with quite large disks, so reconstruction is really slow in case of a power outage. Thankfully, there is the --write-journal option for linux md raid. The man page lists the --...
0
votes
1answer
40 views

Raid1 using Mdadm setup post-install Fedora

I have never messed with Raid before in Linux but while installing Fedora Desktop I tried to setup Raid1. All seemed well at first but alas I look to have failed. So here is how my disks came out. (...
0
votes
1answer
76 views

mdadm RAID comes up inactive each reboot

I have a mdadm software RAID6 that comes up inactive upon each reboot. All its disk are present but shown as spares. How do I make it start operational (active)? This is it's state after reboot: cat ...
0
votes
1answer
43 views

Build RAID 5 with mdadm and 1 disk with data

Since i couldn't find a similar situation with a solution that is understandable for a beginner i thought let's try submitting a question. My goal: I have 3 exactly the same drives (4tb ironwolf) ...
1
vote
1answer
181 views

linux “mdadm --write-journal” and lvmcache - how do they relate?

In linux mdadm man page I saw the option "--write-journal". How does this relate to lvmcache as lvmcache is built on top of dm-cache? Are they different things or does lvmcache do something like "--...
9
votes
2answers
713 views

How does write cache work with a filesystem spanning disks with different speeds?

On a modern Linux system with multiple disks and a software RAID spanning both slow (HDD) and fast (SSD) drives, how are writes to the filesystem cached? For md-raid RAID1 the array can be configured ...
2
votes
2answers
113 views

How many arrays can be created with mdadm?

For an experiment purposes, I need as many disks in a single system as possible. Since I have only six spare disks, I decided to partition them to 128 GPT partitions and create RAID0 array of one ...
1
vote
1answer
80 views

mdadm raid10 recovery - is this filesystem corrupted? Is it fixable?

Background: I had an Ubuntu Bionic system set up and running using 3x1tb disks. The disks were all partitioned with one circa 15gb partition and the remaining circa 983gb. 15gb partitions from two ...
2
votes
0answers
27 views

Can I enlarge a RAID partition?

I have an OpenSUSE 42.3 system with a RAID5 (mdadm) made out of four discs (2 2TB and 2 3TB). I'm growing the RAID by replacing the 2TB discs with larger ones. The 3TB discs have only 2TB partitions ...
0
votes
2answers
123 views

Rebuilding mdadm RAID 5 array with multiple failed drives

I had a 5 drive Raid5 array and I've had two drives fail. I have fresh drives to swap out, but when I'm trying to start it it complains '/dev/md/0 assembled from 3 drives - not enough to start the ...
4
votes
1answer
318 views

RAIDs disappearing on reboot (Centos 7.5)

I'm trying to create 4 RAID 0 disk arrays on my system running Centos 7.5 and have the RAIDs automount after a reboot. For some reason, only one of the RAIDs /dev/md0 is persistent between boots. The ...
2
votes
1answer
228 views

Extending RAID0 with `mdadm --create --assume-clean`?

I had a 1-disk RAID0 array that I created with a view of adding more disks to it eventually, that was working normally. I created it with (approximately): $ mdadm --create /dev/md0 --raid-devices=1 --...
2
votes
1answer
554 views

Backup existing mdadm array setup

I recently installed mdadm an set up a raid1 configuration involving 2 500GIO drives. Is there a way to backup a RAID configuration somewhere so I could re-load it using a single mdadm command in ...
1
vote
0answers
631 views

Unable to assemble existing RAID array with mdadm

I originally set up a RAID1 array on Windows with RST (not as a bootable disk). I recently started moving everything to xubuntu, so I tried mdadm on my xubuntu partition (dual boot). Installing and ...
1
vote
1answer
257 views

mdadm raid 1 how to remove raid and remove data offset to mount normally?

I have a disk that was in a mdadm raid1 with a btrfs partition. Now I want to use this partition without the raid stuff and mount it normally. I already zeroed the mdadm superblock, but now the ...
0
votes
1answer
232 views

Moving drives currently in software raid to LVM? [duplicate]

I have 3 drives currently set up in RAID 5 via mdadm. I just realized that I goofed and forgot to format them with LVM- is it possible to do this after RAID array creation without losing data?
1
vote
0answers
61 views

(Complicated) RAID hard drive issue

I have a (complicated) RAID hard drive issue: I have a Synology DS413j with 4 hds, hd 3 failed so I decided to replace them. The official support article says to replace them one by one, and being ...
1
vote
2answers
101 views

MDADM - adding a disk to RAID5 with slightly less sectors

Basically I have raid 5 with three disks that are 2TB each. I bought 2 extra 2TB drives however they are few sectors smaller on a newer model - old drives are no longer sold. When I issue /dev/md0 ...
0
votes
0answers
44 views

How to prevent spinning up standby drives on system shutdown?

I have an file archive server with 20+ hard drives attached to it. Since I don't access them very often, most drives are kept in the "standby" mode. This way, even though the server itself runs 24x7, ...
0
votes
1answer
62 views

Mounting an EXT4 partition that is marked as RAID 0xFD

I have one hard drive, with a GPT partition table and three partitions. One partition is SWAP. The other two partitions are marked as LINUX RAID 0xFD, but one of them should be an EXT4 file system. ...
1
vote
1answer
41 views

rebuilding mdadm raid5

I've dusted of a machine of which I want to repair an mdadm raid5 that I messed up. First the raid5 was 3 disks. A spare was added, just before one of the three started to fail. Spare one got used and ...
2
votes
1answer
193 views

What is the best way to explain this LVM output?

I bumped into the issue two days ago about RAID issue on my TS-251+ QNAP. I do not really bother the box until the problem comes. I explored details to find out what type of RAID, how RAID/LVM ...
1
vote
0answers
282 views

Can't run 'update-grub'

I've got some trouble with my Ubuntu-System: update-grub Generating grub configuration file ... grub-probe: error: disk `mduuid/c7ac5a8fef833db7b45d6c2ebb2e20e6,1' not found. But I'm still able to ...
0
votes
1answer
100 views

How to fix mdadm: inactive RAID1 arrays, after unplugging one of the drives in both cases?

TL;DR I need to read and write from / to 2 of my mdadm RAID1 arrays after unplugging one of the drives in both cases and commenting them out of /etc/mdadm/mdadm.conf + updating initramfs, of course. ...
2
votes
2answers
405 views

Slow Write Speed(<2 MB/s) on Unencrypted and LUKS Encrypted ext4 filesystems using mdadm Software RAID1 Debian 8 Dell PowerEdge T330 Server

We have installed Debian 8 on a new Dell PowerEdge T330, there are two partitions, / and /var, in a RAID1 array using mdadm. During testing the primary applications: mysql and tomcat were stopped. We ...
1
vote
1answer
296 views

MDADM - Disaster recovery or move on from the state I put my RAID5 array into

Long story short, for my first thread here, I have a software RAID5 array set up as follow: 4 disk devices with a linux-RAID partition on each. Those disks are: /dev/sda1 /dev/sdb1 /dev/sdd1 /dev/...
0
votes
0answers
165 views

Backup mdadm configuration does not work

I backup my raid50 with mdadm --detail --scan --verbose >> /etc/mdadm.conf. Output of mdadm --detail --scan --verbose is: ARRAY /dev/md1 level=raid5 num-devices=3 metadata=1.2 name=1 UUID=...
1
vote
1answer
615 views

Create Software RAID 1 - unexpected failure opening /dev/md0

I want to create a Software RAID 1 on my Debian. Unfortunately when I execute sudo mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1 it returns me mdadm: unexpected ...
1
vote
0answers
223 views

Moving a debian system to another computer: problem with software raid

I have moved my hard discs (with a working debian stable system on it) from a computer which had hardware problems to a new, similar one. I would like to have the old system running on the new ...
1
vote
1answer
26 views

Is it possible to hide mdadm source devices?

If I set up mdadm and I get a /dev/md* device, is it possible to hide from plain sight the underlying source devices that make up the array? I wouldn't want to accidentally write to /dev/sd* that is ...
0
votes
1answer
123 views

CentOS trying to mount non existant RAID array -> recovery mode

My first try using RAID1 ended with CentOS not starting anymore - throwing me into Recovery mode. Luckily a test system At first i set-up the raid1 which worked rather good. Later i noticed that my ...
0
votes
0answers
25 views

Help with mdadm will not reassemble

mdadm --misc --examine /dev/sdb5 /dev/sdb5: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : 056db792:27540abc:cc95d3b1:862cd0d6 Name : DM061:1 ...