A linux utility used to manage software RAID devices.

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mdadm one disk sometimes is missing after reboot

On a debian system my home directory is on a raid1 md array. After creation it worked fine for some time, but once the second drive disappeared from the array. # cat /proc/mdstat Personalities : ...
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New mdadm RAID vanish after reboot

I have problems with mdadm after reboot, I can't reassemble /dev/md0 . I work on debian wheezy. I have done the following steps:: sudo mdadm --create --verbose /dev/md0 --level=6 --raid-devices=4 ...
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Recover data from RAID 0 disk images

I have four (4) disks which are in RAID 0, but the (Lacie) hardware enclosure failed and I'm trying to recover the data stored. I'm now trying to rebuild the RAID to access the data stored, but can't ...
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Simple mdadm RAID 1 not activating spare

I had created two 2TB HDD partitions (/dev/sdb1 and /dev/sdc1) in a RAID 1 array called /dev/md0 using mdadm on Ubuntu 12.04 LTS Precise Pangolin. The command sudo mdadm --detail /dev/md0 used to ...
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Can I use an entire drive for as a software raid member?

Can I use /dev/sda and /dev/sdb for my RADI1 configuration? Or do I first have to partition both with a single Linux raid partition?
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Linux MD software raid stripe cache size

From what I can piece together the /sys/block/md0/md/stripe_cache_size is for raid5 and 6 set at a very low default value to avoid starving machines for memory. By increasing this value you can get a ...
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Ubuntu Server 14.04 - RAID5 created with mdadm disappears after reboot

This is my first question on superuser, so if I forgot to mention something, please ask. I'm trying to set up a home server which will be used as file server and media server. I installed Ubuntu ...
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27 views

Is there a way to show RAID details in a similar way to MDADM?

I find mdadm --detail <device> very useful when I need to know what is going on with the device (/proc/mdadm too). Example: /dev/md0: Version : 1.2 Creation Time : Mon Mar 4 ...
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Can I pass disks through Hyper-V to a Linux VM for md RAID on any hardware?

I toyed with the idea in the past few months of virtualizing a workstation machine (with ESXi/Xen/etc), basically having it run some very basic server stuff behind the scenes; this was more of an ...
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655 views

Linux drive permissions for disk used by two systems

I've got a large mdadm-based RAID5 array that I've been using with an Ubuntu 8.04 system. I'm setting up a new 9.10 (alpha 6) system on the same hardware. mdadm does a great job automagically ...
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mdraid 512/4096 sector confusion

I created a new mdraid array on 3TB disks, connected via USB (because the internal SATA ports were used for the old array). $ fdisk -l /dev/sdb Note: sector size is 4096 (not 512) Disk /dev/sdb: ...
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Failed Software RAID0 on Linux - Attempting to recover data

I have a two disk RAID0 software raid (not hardware raid) that is reported to have failed during boot and my OS won't start. Using a Live CD, I get the following output : sudo mdadm -E /dev/sdc1 ...
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Build one logical drive from hdd and ssd drives (with a tweak!)

How is it possible to build one logical drive in linux from two physical drives, hdd + sdd with the below rules: All writes are replicated to both drives (Kind of RAID 1). All reads are only ...
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39 views

mdadm raid 6 stuck on rebuilding

I have a raid 6 running consisting of 9 1TB drives. Some time in the last couple of days, one of them became faulty and the raid startet rebuilding. But apparently it is stuck ... This is the raid: ...
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47 views

How to set boot disk after disabling mdadm raid 1?

I had two disks in raid 1. The device contained the whole system. Disabled it from a rescue disk with: (there were three partitions) mdadm --stop /dev/md1 mdadm --stop /dev/md2 mdadm --stop /dev/md3 ...
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mdadm: Win7-install created a boot partition on one of my RAID6 drives. How to rebuild?

My problem happened when I attempted to install Windows 7 on it's own SSD. The Linux OS I used which has knowledge of the software RAID system is on a SSD that I disconnected prior to the install. ...
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Does RAID1 increase performance with Linux mdadm?

I have a cheap 2-bay NAS with a 2TB HDD. To be robust against disk failure, I'm thinking of buying a second 2TB HDD and putting it in RAID1 with Linux mdadm. The file system is ext4. Will this ...
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Is it safe to put harddisks of a md-software-raid to standby?

I have a home-fileserver with 6 desktop harddisks in a md-raid. The server isn't accessed a lot, so I think it would be good for the harddrives to go in standby-mode after some idle time (e.g. with ...
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Redundancy: LVM+mdadm or LVM internal RAID

The task is to create LVM storage for virtual machine images. So LVM will be used in any case. There are two ways LVM providing redundancy: block mirroring lvcreate -m 1 --mirrorlog mirrored -n ...
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mdadm partiton not large enough to join array

I've used Linux on and off for the last many years, mainly as dual boot or as Virtual Machines, but when I decided to build a Dev Laptop I though I'd bite the bullet and put Linux on as the base OS. ...
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Hybrid Raid-1 HDD + SSD — Write Intent Bitmap

I am currently running a laptop with 1 HDD and 1SSD. I currently am using mdadm to put some partitions in a raid 1 configuration with --perfer-write set on the HDD. I have this working correctly ...
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950 views

How do I recover data from only a single drive in RAID 1 setup on Synology DS214+ NAS?

I'm doing this so I know how to recover my data in case the NAS itself dies out and I'm only left with just a single drive from the 2nd bay (or from the 1st bay). Setup Synology DS214+ NAS 2x 4TB ...
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mdadm: safest way to grow RAID 5 (4x2TB) with 2x4TB

My situation:I am currently running a RAID 5 with 4x2 TB disks and would like to grow the array with 2 x 4 TB disks. The goal would be that there is a RAID 5 with 4 x 4 TB (the two 4 TB disks and two ...
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491 views

Convert RAID 1 to RAID 10 in mdadm

In my current Ubuntu server, I have 2x 2TB Western Digital RED hard drives in a RAID 1, using mdadm. I would like to add 2 more 2TB RED drives, and convert it to a RAID 10. I realize I would have to ...
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355 views

Understanding /proc/mdstat [U_] VS [_U]

My server is set up with raid1. A few nights ago sda fell out completely and data was corrupted. I replaced the drive, cloned the partition table and added the respective arrays. While adding sda3 ...
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3k views

How do I tell mdadm to start using a missing disk in my RAID5 array again?

I have a 3-disk RAID array running in my Ubuntu server. This has been running flawlessly for over a year but I was recently forced to strip, move and rebuild the machine. When I had it all back ...
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Is there a safe way to move a partition beneath a linux software RAID5 using mdadm?

Suppose, for example, that you have a RAID5 across multiple disks and you would like to retire the oldest of the disks and replace it with something from this decade. I know I can fail the partition ...
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Adding drives to a RAID 10 Array

How would I grow a RAID10 array using mdadm? Obviously I would need to add 2 drives at a time, or would it have to be 4 drives? I have a feeling its just a bad idea. Or would be just wiser to just ...
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78 views

Recover software RAID

I built a RAID-1 with two hard drives using mdadm. Command used was: mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb /dev/sdc it went fine, I create partition table and partitions in ...
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install mdadm with out user input in debian

I am switching to debian from ubuntu and setting up RAID0 on my AWS boxes using user-data. Things were working fine on ubuntu but on wheezy apt-get -y install mdadm --no-install-recommends throws ...
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How-to change the name of an MD device (mdadm)

Here is the output from mdadm -Esv: ARRAY /dev/md127 level=raid0 num-devices=2 UUID=d89d9d45:9a420812:c44c77eb:7ee19756 devices=/dev/sdb8,/dev/sda8 This is a v0.90 array. The question is as ...
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mdadm large memory consumption

Hi i'm build mdadm RAID 6 (8 WD Red 3 Tb) on ubuntu 13.10x64 server with ext4 fs When i download torrent on the array, server RAM is filled for maximum cap (8 Gb) memory is free when i manualy enter ...
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mdadm always degraded on reboot - how to solve?

Whenever I reboot, my RAID6 array is always degraded, and I have to force add two drives (seen here after re-adding): Personalities : [raid6] [raid5] [raid4] [raid1] [raid10] [raid0] [linear] ...
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mdadm --assemble fails when /dev/sd[abcde]1 reordered

I am having trouble assembling a small RAID5 due to a recurring reordering of /dev/sd[a-f] on boot (Debian7). md0 was initially using sd[abc]1, it contains a LUKS device, which in turn contains a ...
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648 views

Converting LVM/EXT4 to ZFS without losing data

I have a home media server with 2 x 3TB drives in it. Its currently set up using mdraid (1), LVM and EXT4. The setup was done using the ncurses Ubuntu Server installer. Goal Convert the setup to use ...
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Checking if Luks header is damaged

Is there any way to check if the Luks container header is damaged? My luks container is refusing to be opened with its keyfile, saying No key available with this pass-phrase. History of what ...
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mdadm disk partition type : Linux RAID Autodetect mandatory or 83 Linux ok?

Main question : Q1: i would like to know when using mdadm, the "Linux RAID Autodetect" type is mandatory for my disk, or a "83 linux" type is ok ? Sub question : Q1_1 : What are the differences ? ...
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XFS: Mount overrides sunit and swidth options

I have a 9TB XFS partition consisting of four 3TB disks in a RAID-5 array with a chunk size of 256KB, using MDADM. When I created the partition, the optimal stripe unit and width values (64 and 192 ...
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Linux software RAID robustness for RAID1 vs other RAID levels

I have a RAID5 array running and now also a raid1 that I set up yesterday. Since RAID5 calculates parity it should be able to catch silent data corruption on one disk. However for RAID1 the disks are ...
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mdadm: faulty Array, how to get recover as much as possible?

I have a RAID5 with 4 Disks in my PC. All of them were healthy (and the RAID itself) until before. I tried to install windows 8.1 which automatically creates this "SystemReserved"-Partition. The ...
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What are the risks of running a software RAID 1 array in degraded mode?

I'm replacing my workstation's system drive and would like to in the future be able to easily add a second drive to form a proper (although software) RAID 1 mirror. For the time being, however, I'm ...
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281 views

XFS in-memory corruption after hibernate

I am constantly getting the below errors with XFS filesystem present on software raid-1 which was then converted to 3-disk raid-5. Errors happen exclusively after hibernate, normally either ...
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Writing to a specific drive with software RAID4 on Linux

Edited to reflect conclusions from comments: I want to construct a software RAID-like array with 2 storage devices plus one parity device, where the parity device maintains the XOR of the two other ...
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222 views

Documentation for mdadm bad block support

I've read a bit about that mdadm (and the kernel) now have bad block support but I am having a hard time finding any useful documentation on this subject. Is the bad block list for disk X duplicated ...
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Non Raid - Symbolic links

I have 3x 3TB drives and 2x 1TB drives. I want to use all drives without RAID, but to be shown as a single volume. So that if a drive fails only the information on that failed drive will be lost. ...
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177 views

RAID10 Recovery

I had a RAID10 array fail a few nights ago, I have to admit that I am fairly lost on all of this. I have googled this extensively and I don't understand what is going on. If anyone here can provide ...
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How does one enable --write-mostly with Linux RAID?

Unfortunately the mdadm and mdadm.conf man pages are not quite up to par. I would like to enable the --write-mostly flag for my RAID, but neither the man pages nor the internet will tell me how. I am ...
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Assembling an mdadm array with “possibly out of date” disks

I've recently moved house and have had some power problems after switching on my file server that's using a mdadm RAID5 set up. The file system I'm using is ext4. It seems that at some point two (of ...
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How can I make mdadm auto-assemble RAID after each boot?

I successfully created a RAID (mirroring) by utilizing mdadm. However, I must run the following commands after each boot: mdadm --stop --scan // to stop /dev/md127 - I don't know where the number 127 ...
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Raid drives missing filesystem

I recently had to do some troubleshooting with a RAID 5 on Ubuntu Server (a software raid). I ended up removing everything and start from scratch with 2 new drives. So I took out 2 out of 4 drives, ...