A linux utility used to manage software RAID devices.

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Cannot install grub, segmentation fault, unable to identify filesystem, superfluous RAID member, found two disks with same index — Debian 7

A server was recently transported from location A to B, a long journey that took six months. Things have gone wrong due to nothing being labeled prior to shipment. Yes, I know --- it was done by ...
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Grub rescue, will not boot from mdadm RAID, no such disk or device — mduuid wrong?

I am running a 14 disk RAID 6 on mdadm behind 2 LSI SAS2008's in JBOD mode (no HW raid) on Debian 7 in BIOS legacy mode. Grub2 is dropping to a rescue shell complaining that "no such device" exists ...
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Recover mdadm RAID 10 array: listing all as spares

I'm a bad person and haven't backed up my RAID elsewhere. I now have a RAID10 array that won't assemble, and I'm hopeful I can save it. Here's the details: I have five hard drives set up as RAID10 ...
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flashcache with mdadm and LVM

I am having trouble setting up flashcache on a system with LVM and mdadm, I suspect I am either just missing an obvious step or getting some mapping wrong and hoped someone could point me in the right ...
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35 views

Can't mount my hard drive

When I try to mount one of my hard drives, it can't locate the folder with the hard drive. This is the output for the command df: Filesystem 1K-blocks Used Available Use% ...
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Resize openSUSE 12.3 GPT ext4 partitions in a RAID1 disk array

I have a software raid configured (/dev/md2) which has assigned the partitions sda3 and sdb3 from two 3TB disks (sda and sdb). The partition types are GPT not LVM and file system is ext4. Now, the ...
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mdadm RAID6, recover 2 disk failure during reshape

I was reshaping my array from 10 disks to 11 to a degraded state (drive I want to add already has data on it, but nowhere to put it). 2 drives disconnected while it was running (power issue). Is it ...
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26 views

Write cache settings not working

I am using Debian 8.0 x64 with 72 GB of RAM with 4 drives configured as software RAID 0. Linux s1 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1 (2015-05-24) x86_64 GNU/Linux I tried setting dirty ...
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Linux mdadm software RAID 6 - does it support bit corruption recovery?

Wikipedia says "RAID 2 is the only standard RAID level, other than some implementations of RAID 6, which can automatically recover accurate data from single-bit corruption in data." Does anyone know ...
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Very poor disk performance on KVM node - mdadm raid10

For a long period of time, i'm experiencing performance issues on CentOS servers that are used for KVM virtualization. I'm running software RAID-10 with 4 disks (Seagate ST2000DM001, 2TB, 7200rpm ...
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mdadm, RAID5 all disks marked as spare, won't start

RAID5 config with mdadm and 4 disks After some incidents, eg one of the drives was lost, had to reboot the server and rebuild the array, my raid is in a funny situation cat /proc/mdstat ...
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120 views

Hard disk / SSDs - detection and handling of errors - is silent data corruption reliably prevented?

When an error occurs on a drive, is it correct to assume that it will always be detected and reported to the OS (if software RAID such as mdadm) or RAID controller (if hardware RAID) as a failed read ...
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16 views

mdadm and LVM high load and IOwait

I've got a new CentOS 6.6 server with 2 HDD with mdadm & LVM. As I've used the CentOS install CD I assume everything should be aligned properly. I've just written a KVM image to a LVM LV using dd ...
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51 views

Mount a NTFS Raid0 disk under linux debian

In my new laptop I have a a RAID 0 configuration with a normal disk and a smaller SSD drive. I have removed the dvd bay and replaced the dvd player with a 256 GB SSD drive where I run linux debian. I ...
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51 views

RAID 5 reshape freeze

I recently added a new disk to my RAID5 array and started growing it. Absent minded as I am I rebooted the server during this reshape process I as another program was hung and blocking some ports. ...
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49 views

Increase space on RAID 10

I have a RAID10 with 7 working devices ,4 actives and 3 spares .I want to increase the RAID's space from 4 devices to 6 . i use this : sudo mdadm --grow --raid-devices=6 /dev/md0 but it gives me ...
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37 views

How to add disk back to RAID and replace removed

Received a message that RAID went into degraded state: Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid1 sda1[0] sdb1[1] 524224 blocks ...
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34 views

Proper way to identify member devices in mdadm.conf

My current mdadm.conf looks like: $ cat /etc/mdadm/mdadm.conf DEVICE /dev/sdb1 /dev/sdc1 ARRAY /dev/md0 metadata=1.2 spares=0 UUID=357ff7cc:55e78d18:9fc7917b:f5b253f2 MAILADDR me@example.com Since ...
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Ubuntu RAID1: How to boot after (physically) removing /dev/sda? (mdadm, Grub2)

Several months ago I installed Ubuntu 14.04.2 Server (x64) with RAID 1 using the following instructions: https://help.ubuntu.com/lts/serverguide/advanced-installation.html I followed the ...
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Where do md array definitions come from?

I created a md array in an ARM computer with two USB/SATA disks in RAID 1. Then I moved both disks to my Ubuntu desktop and installed mdadm. Installation detected the RAID and added the definition to ...
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Can't see other VHDs after detaching another. Azure Ubuntu VM

We have encountered high Disk IO on our Ubuntu 14.04 VM's running mongoDB. On Windows Azure. To solve this issue we have changed the VM size from A2 to A3 (to add the additional data discs) and ...
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54 views

Linkstation WXL: RAID disappeared, /dev/md2 is inactive - how to troubleshoot

today I had problems accessing the SMB-share on my Linkstation. My NAS has two hard drive disks, configured as raid0. this raid was mounted to /mnt/array1/intern - the folder that i am missing. My ...
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MD RAID Array Often Starts Without All Drives

I find that, when I start/restart my system, my MD array often doesn't start with all of the drives even though the device-names haven't changed at all. I'll have to stop the array and reassemble it, ...
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36 views

Software RAID 1 does not extend on two new additional drives

I added two new devices two my software RAID 1 system. They are recognized by mdadm but I can't use the addition space. Here is how I proceed: I added the two new disk to my PC and created on each ...
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36 views

Recover overwritten RAID5 array (XOR)

as I've mentioned in a recent question (RAID5 rescue with LVM2 running on it) I'm rebuilding an RAID5 array. Now, I think that the initial wrong mdadm --create ... command has started the ...
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162 views

CoreOS on software RAID with EXT4 filesystem

I'm currently thinking about installing the CoreOS on a bare-metal server with two disks I want to put in a software RAID1. The latest CoreOS is now using EXT4 as their default filesystem and I'm ...
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51 views

Resetting root password on Slackware (software RAID)

I'm trying to reset password to root account on Slackware server (with Intel Atom on Intel motherboard and two HDDs). There is software RAID set up (devices mounted during boot: md0 - /, md1 - /usr, ...
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28 views

mdadm does not let me set --size manually, but grows to the same size later

I'm trying to make raid1 out of 2 disks the size of which differs a lot (ec2 provides iops based on disk size, so I want to have more iops, but don't care about losing some free space). However when ...
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47 views

Remove a drive from a 2-drive RAID 5 array using version 1.2 metadata?

My situation is nearly identical to "How to remove a drive from a non-standard 2-drive RAID 5 array?", except my 2 TB RAID5 is using mdadm super block version 1.2. According to the best answer, ...
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Shrinking LVM Volumes

We have a Synology RS3614rpxs NAS head containing (9) 3TB hard drives in a RAID 6 + 1 hot spare. The storage became exhausted and we added an expansion chassis where 5TB hard drivers were installed ...
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mdadm 3-way RAID 1 - good solution for guaranteed 2-drive failure tolerance?

Is a 3-way RAID1 using mdadm a good solution to be able to sustain any two drives failing without the RAID failing? I know this costs extra in the sense of only being able to use 1/3 of the disk ...
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211 views

Can mdadm convert a RAID5 to a RAID1?

I have a RAID5 consisting of 3 disks, one of which is broken. I was wondering if it is possible to convert those two disks to a RAID1 without data loss and without having to back-up the data ...
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Data recovery seems impossible after kernel upgrade. MDADM (Raid1) LVM2

I opened a question about rebuilding a bad partition My Problem that din't take me anywhere. Bad news is the company trying to rescue the data says it's finding huge inconsistencies they can see some ...
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mdadm: Convert RAID10 to RAID1

The machine in question is equipped with 4x ssd, and running Debian wheezy 7.8, linux kernel 3.2.0-4, mdadm v3.2.5. Currently I'm using a RAID10 consisting of all these ssd. I've to increase the ...
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Software Raid: Array inconsistent state

I'm running software raid 1 with md on debian distro. One of the disks has failed, but not all of the raid arrays were at that time in a "fail" state. In order to bring them also in a fail state (in ...
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Rescue mdadm RAID 6 array after three disk events

mdadm 3.2.5, 14 disk RAID 6 Had a drive failure Friday. Two more today in rapid succession. All drives seem fully operational. This is roughly 40TB array, I could use your help please to rescue ...
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How can I force soft raid to read only from one disk?

I have quite a large IO wait showing in top. I suspect this is fault of SDA drive (on of 2 disks in RAID array), which was replaced about week ago. There are no errors visible, smart showing nothing, ...
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Linux software RAID6: rebuild slow

I am trying to find the bottleneck in the rebuilding of a software raid6. ## Pause rebuilding when measuring raw I/O performance # echo 1 > /proc/sys/dev/raid/speed_limit_min # echo 1 > ...
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mdadm array keeps losing disks on separate SATA controller

My Ubuntu Linux server has an mdadm array (RAID 5) with four 2TB SATA disks that keeps "loosing" two disks from time to time. Rebooting and re-assembling the arrays has worked out fine up until now. ...
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Linux RAID1 Software - grub resync after fail

I've a linux server with 2 IDE HD & Raid (hda - hdb) I've changed the "BAD" hdb with a new: mdadm --fail /dev/md2 /dev/hdb3 mdadm --fail /dev/md0 /dev/hdb2 mdadm --fail /dev/md1 /dev/hdb1 ...
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Is there any way to build a linux software raid system without all drives?

I'm building a raid1 (ok it will probably be a raid10,f2 but the difference with 2 drives... isn't much) system with 2 1TB drives. However, 1 of the drives I've ordered is bad so I'm RMA-ing it. I'm ...
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Can't resize2fs - combination of flex_bg and !resize_inode

I recently set up my first software raid with mdadm and after adding more disks to the raid I am unable to resize the filesystem to the full size of the raid. I created a single (~16TB) filesystem on ...
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To write in mdadm.conf in initramfs prompt doesn"t not save changes after reboot

I made a mistake with my mdadm.conf with my debian backup server. I used this command : mdadm --detail --scan --verbose >> /etc/mdadm/mdadm.conf to add a raid5 (it works great). By using ...
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Grow individual drive size in RAID5 array

My array is built of 3 hard drive of 2TB, I have 2 more free space and I would love to start to grow my array with 4TB hard drives, if I start to put 2 4TB hard drives and eventualy replace the 2TB ...
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In a software RAID1, why does tune2fs -c 0 /dev/sda1 not throw an error but change is not seen in tune2fs -l /dev/sda1?

The Title pretty much says it all. Turn off mount count fsck seems to succeed: tune2fs -c 0 /dev/sda1 tune2fs -c 1 /dev/md0 But listing out via tune2fs -l /dev/sda1 shows mount count is set back ...
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How to have automatic file system checks for Linux Software Raid?

In a Linux Software raid, what is the best practice for periodically having the filesystems checked? With single drive or hardware raid, tune2fs -c 5 -i 1w /dev/sda1 means check the filesystem every ...
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67 views

Files missing after RAID1 restore

I have encountered unpleasant situation. Given mdadm RAID1 of 2 HDD on server. Yesterday one of HDDs completely dies, other shows bad SMART status but was in accessible state. Mdadm showed "clean, ...
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103 views

mdadm: activating spare and removing 'removed' disks

I added 1 disk to my raid array, started reshaping, and then remembered that I forgot to partition the drive. So I partitioned and readded the disk. I'd like to get rid of that 'removed' and activate ...
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337 views

Restore lost RAID1 volume on Synology with mdam

Several days ago I found my DS412+ in fatal state. Volume1 crashed, system volume too. Moreover, Volume2 disappeared from the system! It looks like Volume1 had no free space and cannot transfer data ...
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100 views

Ubuntu server becomes unresponsive on hard disk issues despite raid setup

I am running a server on Ubuntu 10.04.4 LTS (Linux xxxx 2.6.32-67-server #134-Ubuntu SMP Wed Sep 24 18:55:00 UTC 2014 x86_64 GNU/Linux) with two hard discs in a software raid 1. I repeatedly had the ...