A linux utility used to manage software RAID devices.

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mdadm: superblock on /dev/sdd1 doesn't match others - assembly aborted

OS: Debian Squeeze Kernel: 2.6.32-5-amd64 mdadm version: 3.1.4 (31 August 2010) mdarrays md1 = raid1 (this is working) (devices: /dev/sd[fg]1) md0 = raid6 (previously raid5, ...
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367 views

Migrate mdadm raid array from 32bit to 64bit debian squeeze

I have a raid5 array running on Debian Squeeze 32bit (x86) and I plan to upgrade to Debian Squeeze 64bit (amd64). To keep my raid5 array and ext4 filesystem I simply keep a copy of my mdadm.conf ...
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863 views

Take one disk of external mdadm data raid 1 to travel

I have a mdadm software raid 1 on external disks with media data. For travel I want to take the data with me. I imagine to set the raid and the underlying filesystem in readonly mode and take just ...
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3answers
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mdadm Ubuntu 12.04 fails to assemble RAID6 during boot

I will try to keep this short. I have a mdadm RAID 6 with 11 drives. This has for years "just worked" across reinstalls and such, without any issues. I have not even had the need for configuring ...
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158 views

How to grow an EBS mdadm raid 10 array?

Is it possible to grow a RAID 10 array? Can I take it offline and grow it? Or do I have to make an entirely new array, and copy all the data onto it?
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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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How do I reinitialise a failed RAID 5 drive using terminal on Ubuntu Server

I've currently put together a new system and part of that has been creating a software RAID 5 using 'mdadm' in Ubuntu Server. I successfully got to the point where I create the array using: sudo ...
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mdadm RAID Fast Setup with Empty Drives?

I am recreating some RAID5 disks as RAID6 with mdadm. There is no data on the drives that I care about. Setting up RAID takes a while to setup the shape - I accept that when there there is data that ...
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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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575 views

mdadm recognizing array incorrectly how can I recover the data

So I formatted both disks sd[cd], each as a big ext4 partition, and then used mdadm to create a raid0 array sd[cd]1. This worked fine, and I mounted the device and started storing data on it. Prior to ...
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624 views

Getting advanced format drives to like new?

I have 5 2TB WD Green (WD20EARX) drives that I eventually want to put into software RAID 5. I can't seem to find a complete guide on getting these drives prepared for use with Ubuntu (mdadm) that ...
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736 views

Safety of Truecrypt for Large Raid5 using ubuntu, mdadm, lvm, ext3?

I'm planning to set up a large (probably 6-9Tb) raid-5 array on ubuntu using mdadm, lvm and ext3. Does anyone have any opinions or suggestions on the safety of using a Truecrypt volume for that amount ...
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723 views

Adding Space to RAID5 using mdadm, lvm and ext3

I have seen a few descriptions about using mdadm with lvm to create an easily expandable raid, such as this question, but I still think I'm missing something. Say that I create the raid using mdadm ...
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4answers
1k views

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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3answers
924 views

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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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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957 views

mdadm: hot remove failed

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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mdadm raid5 read error not correctable

I have a software raid5 setup existing of 4 disks. sda, sdb, sdc, sdd Since everything was up and running I wanted to test the array. To do this I pulled the plug on one of the disks (sdd). Everything ...
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127 views

How to identify raid1 disks

I would like to know how mdadm identifies physical disks of raid1 . I think it is managed by uuids not device file like /dev/sdc2 /dev/sdd2. But I can`t confirm such information of raid1.
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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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Fault tolerant RAID6 / RAID10 design for home server - not performance critical

I want to balance disk space against fault tolerance. I would like fault tolerance to be able to handle multiple disk failures (as I may not be able to afford replacements disks or have the time for ...
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2answers
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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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4answers
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How do I mount a software RAID1 (mirror) created by windows in Linux using mdadm?

I'm switching my Windows server to Ubuntu and am trying to get my software RAID1 (mirror) that I created in Windows to show up in Ubuntu. I have read that this is possible here using mdadm, but I'm ...
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degraded mdadm RAID5 array

My /dev/md0 array just died last night. I got this email This is an automatically generated mail message from mdadm running on A Fail event had been detected on md device /dev/md0. It ...
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281 views

Is it possible to safely get data off a hard drive thats a member of a mdadm-mounted RAID1 array via USB?

I have a RAID1 array of two drives created with mdadm. Is it possible to remove one of the drives, hook it up to a USB SATA adapter, and safely mount it, get the info off of it, and return the drive? ...
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Btrfs on top of a mdadm raid10, or btrfs raid10 on bare devices?

I have a RAID10 managed by the mdadm and I have EXT4 filesystem on top of it. However, I like BTRFS and would like to convert the EXT4 filesystem to BTRFS, but I was thinking about performance and ...
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1answer
897 views

How to remove a drive from a non-standard 2-drive RAID 5 array?

There is some information available on shape changes in RAID arrays but I'm a little nervous and would like confirmation: Problem: I have 2 500GB drive as software raid 5 (mdadm). I would like to ...
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1answer
703 views

CentOS - mdadm raid1 drive won't mount to default location

I'm running CentOS 5.5, the system, boot, swap, etc. is all on /dev/sda and I have two identical single-partition drives /dev/sdb1 /dev/sdc1 that are configured in RAID1 (using mdadm). It was working ...
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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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5k views

determine chunk size of an existing raid array

What should I do to determine chuck size of existing raid arrays. I'm using software raid created by mdadm. I've been probing around for a while and can't find the right utility to that job. mdadm ...
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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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2answers
264 views

What would you see if you tried to mount a single drive from a RAID 5 Array?

The title pretty much sums it up - if someone were to mount a single drive from a software RAID 5 array, what would they see? Would it point to being part of a RAID array, appear as encrypted data, or ...
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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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850 views

Recover Linux software RAID5 array after server upgrade

I recently upgraded a server from Fedora 6 to Fedora 14. In addition to the main hard drive where the OS is installed, I have 3 1TB hard drives configured for RAID5 (via software). After the upgrade, ...
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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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Lots of fun problems with RAID and SATA controllers

I bought a used 3ware raid card off of ebay a few months back and set up four 1TB caviar blacks in RAID5. The hardware raid could only manage about 5MB/s writing without write caching, and I don't ...
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309 views

Recover from failed recovery of software RAID5 failure

I have the pleasure ;-) to have been handed the task to try to get data off a server that had a RAID5 array problem and a failed attempt to recover it. Background: the computer in question is some ...
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905 views

mdadm raid-1 after restarting usb devices not accessible anymore

Is my mdadm software raid in danger of data loss??? My both two new built raid-1 on external usb disks behave strangely. Both were fine and rebuilt and cat /proc/mdstat showed Every 10,0s: cat ...
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raid-1: increase rebuild speed on current rebuild

I see my raid-1 array rebuilding (first time after adding 2nd partition) and want to increase speed SO I set echo 100000 > /proc/sys/dev/raid/speed_limit_min echo 400000 > ...
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162 views

Can RAID5 drives be defective while passing self-tests?

I have a 4-drive RAID5 in Ubuntu 10.10 with mdadm. One of the disks seems to be problematic. It dropped from the RAID, and I re-added it and it was fine for a while, but now when I re-add it I get a ...
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3answers
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Raid1 with active and spare partition

I am having the following problem with a RAID1 software raid partition on my Ubuntu system (10.04 LTS, 2.6.32-24-server in case it matters). One of my disks (sdb5) reported I/O errors and was ...
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1answer
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Auto-rebuild RAID6 with MDADM

I have an openSUSE 11.3 Linux computer with 5 disks of 1TB (WD enterprise disks) in it. With mdadm I configured a RAID6 device. Now, after a lot of thorough testing, I've noticed that when the ...
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1answer
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convert full-disk RAID5 array to partition-based array?

I have a RAID 5 array, md0, with three full-disk (non-partitioned) members, sdb, sdc, and sdd. My computer will hang during the AHCI BIOS if AHCI is enabled instead of IDE, if these drives are plugged ...
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mdadm volume works, but won't assemble/mount on startup?

I have an mdadm/lvm2 volume with 4 HDs that I created in Ubuntu 10.04. I just upgraded the computer to Ubuntu 10.10. I redid the mdadm commands to get volume up and running, did mdadm --detail --scan ...
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Fluctuating transfer speeds with md RAID5/vsftpd

I have an Ubuntu 8.04.4 server with an md RAID5 consisting of 9 drives. While transferring a large amount of data to it (through vsftpd) I noticed very bad transfer speed fluctuation. For example ...
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mdadm device missing

after a reboot my /dev/md0 device was missing. This is a RAID-1 array from two partitions of two harddrives. On each of the harddrives is another partition, which together belong to dev/md1. However, ...
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1answer
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how can fsck to recover from hardware failure?

I have a RAID 5 array using mdadm and ext4 as its filesystem. We got a strong power surge and one of the drive faulted, while another one got a bit flakky, aka "click of death". I replaced the disks ...
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356 views

Paritions “appear” in my raid 1 array after reboot, and the partitions in the array have changed names

I am moving my Ubuntu install to lvm over raid 1. I created the arrays with only 1 disk initially, planning to add the second disk later. I got the files moved and the system booted up succesfully on ...
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Possible mdadm RAID states?

I'm writing a monitoring plugin for a home server RAID, mdadm on Ubuntu 10.4. Using sudo mdadm --detail /dev/md0 I get output like this: /dev/md0: Version : 00.90 Creation Time : Thu Dec ...
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201 views

Gentoo Linux -> Ubuntu: Can I Preserve My LVM/RAID Devices, Or Do I Need To Reformat?

I've got a Gentoo box that I'm interested in switching over to an Ubuntu box. I currently have the partitions laid out using a mixture of RAID (mdadm) and LVM2, as specified in this document [1]. ...