A linux utility used to manage software RAID devices.

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How do I get mdadm to auto assemble my raid array?

After upgrading to Ubuntu 9.04, my raid 5 array is no longer being assembled correctly. Right now, from boot, it will start a raid array using ata-MAXTOR_STM3500630AS_9QG03T0L-part1, at /dev/md0, but ...
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68 views

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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6k views

DegradedArray event on /dev/md1

This morning I got this message: This is an automatically generated mail message from mdadm running on A DegradedArray event had been detected on md device /dev/md1. Faithfully yours, etc. P.S. ...
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mdadm Boot Error, incrementally starting raid array Ubuntu SErver 14.04

i build a small Server with Ubuntu 14.04 for Samba, I has one SSD Drive (the ubuntu installation is on it) and 2 3TB SATA Disk, the sata disk are combined to a Raid 1 with mdadm. Now sometimes (no ...
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1answer
1k views

Rebuild mdadm RAID5 array with fewer disks

I have a 4 disk RAID5 array, one of which is starting to fail according to smartd. However, since I'm using less than half the space on /dev/md0, I'd like to rebuild the array without the failing disk....
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1answer
2k views

Remove “faulty state” in RAID 1

I wonder if there is any possibility to remove the state "faulty" in a RAID 1 if (for example) someone failed the wrong hard disk. I already searched for answers with Google and found several ...
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466 views

reshaping raid and growing raid

This is a two part question. 1) Can you reshape raid 5 to 6 with mdadm on linux (fairly sure you can, but cant get mdadm to accept it) 2) Can you do 1) while also growing the array in one go ?
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What are the advantages and disadvantages of constructing an mdam array from whole disks vs. partitions?

Let's say I've got six identical drives and I'm going to use them all in a RAID10,f2 array constructed using mdadm. I've always put a single partition on each disk and constructed the array from /dev/...
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mdadm --zero-superblock on disks with other partitions on them

I have three disks which used to hold an MD RAID5 array. I have since removed (or so I thought) this array and created partions for btrfs and swap space. On rebooting the machine, MD still binds the ...
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apt-get update mdadm scary warnings

Just ran an apt-get update on one of my dedicated servers to be left with a relatively scary warning: Processing triggers for initramfs-tools ... update-initramfs: Generating /boot/initrd.img-2.6.26-...
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Slow md RAID-1 array

We have some problems with very slow disk response on our server. I checked iostat (iostat -d -x 30) and have some problems with its interpretation: Device: rrqm/s wrqm/s r/s w/s ...
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Impossible to stop raid device

I'm trying to stop a RAID disk in order to replace it by a new one, as this one is not working properly. I'm typing mdadm --stop /dev/md1, and I'm getting an error message: mdadm: fail to stop array ...
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1answer
3k views

How do you set up RAID1 with both disks bootable on Debian/Ubuntu?

In Debian 6, new installation, what is the recommended way of setting up a software RAID1 array so that the system is bootable from both disks? I have heard that people that don't know what they are ...
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3answers
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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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2answers
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Degraded RAID-5 array with lvm2 lost superblock and partition table

I have a RAID-5 array of 4x1TB hard disks with one lvm2 partition on Ubuntu Linux 10.04 LTS. One of the disks has failed. I have re-assembled the array without this failed disk but now mdadm --examine ...
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1answer
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CentOS 6.5 mdadm Raid 1 - Kernel Panic during raid data check

I have a brand new CentOS 6.5 install with two (mounted to /mnt/data) 1tb Western Digital Black drives in raid 1 with mdadm, configured via the installer. Unfortunately every now and again the entire ...
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1answer
1k views

How to get rid of a stubborn 'removed' device in mdadm

One of my server's drives failed and so I removed the failed drive from all three relevant arrays, had the drive swapped out, and then added the new drive to the arrays. Two of the arrays worked ...
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1answer
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Linux RAID mdadm: what does 'Events' mean?

When I type mdadm --detail /dev/md0 I get a lots of useful information most of which I understand. However I also get a line that reads: Events : 0.710 Where the number varies. Naively, I ...
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1answer
410 views

3 drives fell out of Raid6 mdadm - rebuilding?

i had an mdadm raid6 array with 13x1TB drives. Within 10 minutes 3 of these drives fell out of the array... we assume bad cable to the controller card and replaced, however now we need to get the ...
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1answer
715 views

Debian installation on software RAID (lilo.conf configuration)

Debian installation program has created lilo.conf: boot=/dev/md1 root=/dev/md1 raid-extra-boot=mbr-only But when i configure lilo i usually put these lines disk=/dev/md1 sectors=63 heads=255 ...
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Failed MDADM Array With Ext.4 Partition - “e2fsck: unable to set superblock flags on /dev/md0”

Had a power failure and now my mdadm array is having problems. sudo mdadm -D /dev/md0 [hodge@hodge-fs ~]$ sudo mdadm -D /dev/md0 /dev/md0: Version : 0.90 Creation Time : Sun ...
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1answer
114 views

Why is my HDD partition a character special device?

I have a bunch of old 1T disks with an mdadm array on them. They had been out of commission for awhile, but yesterday I slotted them into a server running an up to date Debian Jessie. Eventually I ...
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1answer
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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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How to recover an mdadm array on Synology NAS with drive in “E” state?

Synology has a customized version the md driver and mdadm toolsets that adds a 'DriveError' flag to the rdev->flags structure in the kernel. Net effect - if you are unfortunate enough to get a array ...
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1answer
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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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1answer
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mdadm: hot remove failed for…

My RAID1 is degraded and I need to replace /dev/sdb. However, I could mark /dev/sdb5 (in /dev/md1) as failed and removed it, but I can't do the same with /dev/sdb1 (/dev/md0 which is mounted on /): ...
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1answer
557 views

EC2 disk goes to 100% util, but fine after reboot

We've been running some production services on Amazon EC2 for a while, using mainly t1.large and t1.xlarge instances (non-EBS). Every so often one of the attached (ephemeral disks) will get into a ...
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4answers
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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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858 views

Is using nested RAID 6+1+0 a good idea?

Currently I have 24 disks of 500 GB, and I would like to create a bigger nested RAUD using a Dell Power Edge R730 server, having 4 times RAID 6 with six times 500GB each, over them I want to add RAID ...
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Linux RAID 1: How to make a secondary HD boot?

I have the following RAID 1 on a Centos 6.5 server: # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb1[3] 974713720 blocks super 1.0 [2/1] [_U] bitmap: 7/8 pages [28KB], ...
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2answers
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Mdadm won't create an array larger than 10TB

I have a server with six 4TB drives running Ubuntu 14.04 LTS. One of the drives is used for the system/OS I wanted to use the other 5 drives to get as close to 20TB of storage as possible It's a short ...
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1answer
15k views

Unable to mount '/dev/sda'

My server has two 2 TB hard disk drives in soft RAID 1. I can't mount /dev/sda. Output of parted -l root@rescue:~# parted -l Model: ATA HGST HUS724020AL (scsi) Disk /dev/sda: 2000GB Sector size ...
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3answers
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Can I convert a raid10 array to raid0?

I have created a raid10 array using mdadm. Metadata version is 1.2. I want to convert this to a raid0 array, is it possible? P.S. I am having terabytes of data, I want to avoid copying the data over.
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459 views

Degraded partition in RAID5 system

I've got a server running Debian Squeeze and a 3x 500 GB-drive RAID5 system which I haven't set up myself. When booting, the status of one partition in the RAID-array seems to be bad. md: bind<...
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1answer
773 views

mdadm RAID1 to RAID6

I've got a RAID1 array. I'm buying 4 more disks of equal size (they're the same model drives) and I'm trying to enumerate my options for a safe upgrade. Ideally they'll be one large ext3 volume. ...
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1answer
288 views

recover highly degraded raid array

I have a Linux RAID6 array (mdadm) composed of 8 disks. 2 disks failed. I replaced them, now I have 2 new empty disks. I would like to rebuild the raid but when I start a raid rebuild, the rebuild ...
3
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1answer
287 views

Does growing a RAID 5 destroy the data on the RAID?

For a linux software RAID using madadm, does adding a harddrive and growing onto the RAID, destroy the data that's already on the RAID or does it preserve everything?
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1answer
305 views

Debian server has degraded mdadm array on every boot

I have a Debian server with MD raid (2 actives, one spare): Personalities : [raid1] md1 : active raid1 sdc2[0] sdb2[1] sda2[2](S) 1068224 blocks [2/2] [UU] md0 : active raid1 sdc1[2](S) sdb1[...
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mdadm: Disk configuration by UUID

I want to create a soft RAID-5 and use UUIDs im the mdadm config file. So I have four disks with 1 partition each that spans the whole disk. But since the partitons don'5 have a filesystem, blkid does ...
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Raid 5 with 4 disks on Debian automatically creates a spare drive

I'm trying to to create a RAID 5 with 4x 2TB disks on Debian 6. I followed the instructions from: http://zackreed.me/articles/38-software-raid-5-in-debian-with-mdadm I created the raid with following ...
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1answer
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Growing a RAID5 using mdadm with multiple drives?

I have a RAID5 array that consists of 3, 2TB drives. I want to add 2 more drives. The tutorials involve adding a single drive to an array, such as this: https://raid.wiki.kernel.org/index.php/Growing ...
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Is mdadm Raid-1 Over A Network File Share Possible?

I am using 64bit CentOS 5.5 I know it's possible to set up software RAID1 using mdadm using a physical hard disk and a RAM disk. Is it possible to set up software RAID1 with mdadm using a NFS mount ...
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Recover RAID-5 that was already running in degraded mode (lost a second disk)

this is silly, this has happened before and I figured out how to fix it and it was fine. I'm running 4 500GB SATA drives in a RAID-5 on Ubuntu 7.10 server. One of the disks failed (actually I think ...
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Linux raid10 on 2 disks

Linux mdadm has some quirks, one of them is building raid10 with only two disks. There are some reports that it's way faster (twice, both in read and write) as RAID1: https://raid.wiki.kernel.org/...
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mdadm stalls rebuilding a RAID5 array at 99.9%

I recently installed three new disks in my QNAP TS-412 NAS. These three new disks should be combined with the already present disk into a 4 disk RAID5 array, so I started the migration process. ...
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2answers
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mdadm - Recovering a 'split' RAID1 array

I have two drives that used to be part of a single RAID1 volume but it appears that one of them went offline for some time, something I've noticed just now when I rebooted my system. I now seem to ...
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2answers
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Linux Software RAID1 Rebuild Completes, but after reboot, its degraded again

I have been beating my head with an issue here, and I'm now turning to the internet for help. I have a system running Mandrake Linux, with the following configuration: /dev/hda - This is a IDE ...
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2answers
824 views

Reading off of MDADM drives after server died

I had a 2-drive RAID-1 array running on ubuntu, which I had forgotten about. The host I was running them on is now dead, leaving me with these two disks. How can I get data off of them? If I dump them-...
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1answer
137 views

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 ...
3
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1answer
622 views

Linux Raid: mystical md_d device

I have a 64bit Ubuntu Jaunty server (kernel 2.6.28-17-server) installed on two SATA disks (sdc and sde) in a mirror RAID, this being my current raid configuration: cat /proc/mdstat Personalities : [...