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Questions tagged [mdadm]

A linux utility used to manage software RAID devices.

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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 ...
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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 /...
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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 ...
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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 ...
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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 ...
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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, ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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:...
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157 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 --...
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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. (...
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ZFS on mdadm: Implications?

I am considering setting up a RAID array with mdadm/Linux RAID, and using the ZFS filesystem on the resulting device (ie. /dev/md0). Many would suggest using ZFS to create the RAID array directly, ...
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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 ...
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How to boot from mdadm raid1 without marking drive as failed?

I've successfully installed a CentOS 7 with 2 HDDs in a raid1 array with mdadm and I can safely boot from either one of them being the BIOS boot drive and even from having either of them unplugged... ...
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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) ...
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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 "--...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 --...
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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 ...
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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 ...
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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 ...
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186 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?
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(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 ...
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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 ...
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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, ...
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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. ...
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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 ...
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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 ...
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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 ...
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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. ...
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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 ...
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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/...
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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=...
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466 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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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Can I use one physical disk in two mdadm arrays?

I have three disks that I'd like to use in a RAID setup; 2x4 TB 1x8 TB Can I create two partitions on the 8 TB disk and include in two RAID 1 arrays with the 4 TB disks? RAID 1 array 1: 4 TB ...
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How to partition a software RAID

I want to create a second partition on a software RAID 5 created on debian stretch. To create it I used mdadm --create /dev/md0 --auto md --level=5 --raid-devices=4 /dev/sda1 /dev/sdc1 /dev/sdd1 /dev/...
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MDADM - Stop Resync and Force Clean - Possible and/or Safe?

I have been having issues with my FileServer recently. See “rcu_sched detected stalls on CPUs/tasks” - jiffies - ESXi Ubuntu 16 FileServer Guest I just rebuilt it since I couldn't get any guidance ...
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“rcu_sched detected stalls on CPUs/tasks” - jiffies - ESXi Ubuntu 16 FileServer Guest

I have a VERY simple Ubuntu 16 x64 VM setup on my ESXi host which acts as a fileserver. It has NFS/SMB and MDADM installed. It is fully updated. Twice in the last week it has hung with an error ...