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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20 views

Need some more MDADM details

Short version: I am using a RAID1 with hotspare and I want to have a nightly DD ran to create a nightly image on a standby drive. All the drives are the same size/manufacture and local. I am getting a ...
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11 views

Xeon linux with Avago Megaraid RAID card

In brief, my problem is how to use linux's mdadm to reconstruct a DDF-format RAID-6 array that has gotten its superblock metadata borked. Here is my tale of woe. I have (had?) a RAID-6 array composed ...
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13 views

how do i shrink or reduce my raid array size

i have raid array md0 which is close to 5TB. i need to shrink this size so as to overcome the rebuild times when i test fail the drives. is there a tool/command that can help me to reduce the array ...
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1answer
69 views

Linux mdadm does not assemble array, but recreation of array does it

Maybe i'm not very clear in the title. When i'm trying to assemble my raid1 array with mdadm: sudo mdadm --assemble /dev/md0 /dev/sdc /dev/sdd It tells me that mdadm: Cannot assemble mbr metadata ...
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how to force mdadm to sync to device after raid6 repair and how to get number of errors?

The Question After a component device suffered unexpected bit-flip, and after a raid6 repair was successfully performed on the raid device, how to force mdadm to sync the changes from buffer(?) back ...
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7answers
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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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2answers
912 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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6 views

Linux software Raid5 DegradedArray with mdadm

So I changed my case and I don't know why but one my SATA port does not work anymore. So only 5 of my 6 RAID5 disks were recognized. The volume was automounted anyway and I already wrote new files on ...
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12 views

mounting a RAID array on a machine with conflicting device name

I have a machine with the following RAID arrays connected: xxxx@xxxx:~$ sudo /sbin/mdadm --examine --scan ARRAY /dev/md/0 metadata=1.2 UUID=6c2e2072:4db41563:d93a9ae5:dfb29ffd name=xxxx:0 ARRAY /dev/...
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9 views

md-raid1 with three mirrors became raid0 after removing one mirror while power off. how to fix it?

I create md-raid1 with three devices: mdadm --create \ /dev/md22 \ --level=1 \ --raid-devices=3 \ /dev/sd[a-c]2 and got nice raid mdadm -D /dev/md22: /dev/md22: Version : 1.2 ...
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28 views

Migrate MDADM array to another server with degraded state

I've been hacked few days again and, after analysis, I want to have my data back ! My previous server (the one who contains data on RAID1) have been compromised so I've decided to go with another one....
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1answer
16 views

Unable to assemble mdadm array due to lack of errors

My virtual machine host system is running Debian 8.4. I had to restart the system yesterday and did not yet manage to get my mdadm array up and running again. I can boot up normally, but no array (or ...
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4answers
12k views

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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1answer
4k 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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1answer
41 views

SSD failed, mdadm thinks the RAID0 array is fine

I have a RAID0 array created using mdadm in Debian. sdf is the drive that died. $ cat /proc/mdstat md4 : active raid0 sdf1[1] sde1[0] 468859904 blocks super 1.2 512k chunks $ mdadm --misc --...
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1answer
21 views

MDADM two disks of different ages from same array

I have an mdadm mirror. One of the drives was failing, and through not concentrating, the a new drive was mirrored against the failing drive, which had been out of the array for a while, so is a ...
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1answer
93 views

MDADM rebuild raid 6 with 3 'failed' drives

I've ran into the following problem: My Raid 6 (/dev/md6) failed after 3 disks fell out of the array. One of the disks must have been out for a while (in SMART, 5 of the 6 disks have an uptime of ...
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1answer
27 views

How do i prevent lilo from doing a disk scan?

I have gentoo installed using root on LVM on RAID5. I made a mistake when I set up lilo but the initrd created by genkernel caught it and allowed me to type in the correct root partition. I have ...
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19 views

Mdadm raid gone after reboot

Mdadm raid gone after reboot. Will gdisk work on 6TB HDD's? Will some describe how to use "parted" to write "fd00"? Rephrased better
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2answers
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How to force mdadm to stop RAID5 array?

I have /dev/md127 RAID5 array that consisted of four drives. I managed to hot remove them from the array and currently /dev/md127 does not have any drives: cat /proc/mdstat Personalities : [linear] [...
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188 views

MDADM reshape really slow

To sum up : My raid reshape with mdadm is really slow. The complete story : 3 days ago I realized that one of my disks from a raid 5 array was faulty. I removed it and replaced it with a brand new ...
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2answers
3k views

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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97 views

Trying to mount Western digital mybook duo raid 2 disks but fails

I connect both my linux system. I do a bash-4.2# mdadm --assemble --scan mdadm: /dev/md/MyBookLiveDuo:2 has been started with 2 drives. then i try mount /dev/ ash-4.2# mount /dev/md/MyBookLiveDuo:2 /...
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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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76 views

Strange software RAID performance results (on linux)

I have four 2TB 7200rpm hard drives that I want to configure as a software RAID array, using mdadm on linux (Ubuntu 15.10). I took this opportunity to explore the read/write performance of various ...
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9 views

Growing an mdadm RAID array with differently sized disks

I have a raid6 archive array made up of 4 2TB drives (+OS on an independent SSD). I'm starting to run out of space and my target final goal is 4 4TB drives. I don't have enough SATA ports to run both ...
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13 views

Problems reassembling software RAID6

I have a software raid6 array (mdraid) consisting of 6 drives (/dev/sd[f-k] at the moment) at /dev/md1. Because I had to pull a different drive out of the machine (not one of the 6 drives), I ran ...
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2answers
38 views

Ubuntu RAID 10 - unable to assemble

Here's a brief history of how I got here: 4x disk Ubuntu 12.04 software RAID10 with 5x partitions (md0 - md4) 1x disk died mdadm --fail > mdadm --remove > physically removed drive and replace mdadm -...
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1answer
84 views

Does mdadm record array event history?

I received an automated email from the mdadm daemon: A Fail event had been detected on md device /dev/md0. It could be related to component device /dev/sdh. I find the wording strange. "could be"? ...
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54 views

Growing mdadm array; Cannot find backup file on FS where it's supposed to be

The situation: I am currently growing my RAID-6 array from 4x4TB to 5x4TB. To achieve that, I used to following command: root# mdadm --grow /dev/md0 --backup-file=/root/backup/raid/4d_to_5d --raid-...
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6answers
12k views

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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21 views

What is theoretical max benefit from read speeds under RAID5?

I have a 5 drive RAID5 with mdadm. When I do hdparm -Tt on all the constituent drives I find the slowest is about 230MB/s. Is the maximum theoretical limit of read speeds going to be (5-1)*230 or (5)...
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134 views

mdadm not reassembling array on boot

I'm currently using arch on my Asus UX51VZ laptop for almost a month. I have a fakeraid setup with two 256GB SSDs using mdadm. I was using this configuration without any problems. However after I've ...
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37 views

RAID 5 showing two disks in same slot

We recently had a power failure for a few hours and when the power came back both my RAID arrays failed. The one I am trying to fix is a RAID5 with 5 disks (I also have a RAID1 with 2 disks, but I ...
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1answer
124 views

Random kernel panic after re-installing Arch Linux

I recently had two hard drives that crashed in a RAID 5 array, I didn't configure any monitoring, so I didn't notice that one had been crashed for a while. So I decided to scrap everything and start ...
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24 views

Moving from debian to unbuntu - mdadm raid vol going to be ok?

I'm a little nervous about this decision, but I've recently updated the hardware in my NAS/HTPC and Debian wheezy network drivers aren't happy and regularly need to reboot to get eth1 working again. ...
5
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2answers
4k views

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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111 views

Recover mdadm raid5 with XFS

I am trying to recover data from an old Buffalo Terastation that failed. A previous attempt to recover the data by someone else was unsuccesful and I have been left with the following situation. NB: ...
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1answer
83 views

Assemble 3 drive software RAID5 with one disk missing

Is it possible to assemple a three drive software RAID5 with only two disks? I have one failed disk in my setup which i could not read at all but the two other disks are fine. So i created a dump of ...
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1answer
188 views

Fail device in md RAID when ATA stops responding

I had created five 1TB HDD partitions (/dev/sda1, /dev/sdb1, /dev/sdc1, /dev/sde1, and /dev/sdf1) in a RAID 6 array called /dev/md0 using mdadm on Ubuntu 14.04 LTS Trusty Tahr. The command sudo mdadm ...
0
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1answer
46 views

partition device (i.e. /dev/sdd1) not created for hard drive

I am having a similar problem as posted here where a hard drive has an old mdadm signature on it and the partition on it is not given a device file in /dev Unfortunately the solution provided in this ...
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1answer
1k views

mdadm RAID 1 - spare drive after SATA cable change

Yesterday, my hosting provider changed a SATA cable of one of my HDDs. When my server came back up again, cat /proc/mdstat showed this: Personalities : [raid1] md124 : active raid1 sda1[0] ...
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9answers
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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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0answers
241 views

Dual boot Win8/Linux on Asus Zenbook UX301 keeping intel imsm RAID0

I have Asus Zenbook UX301 with Win8 preinstalled. I would like to have a Linux installed in dual-boot configuration. However, Windows is using the notebook 2 SSDs as intel RAID0 (rom-based RAID, ...
2
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1answer
1k views

Unable to reassemble md raid on drives pulled from ReadyNas Duo v1

I'm toying with a ReadyNAS device that I've recently acquired. It is a SPARC-based box, and it runs linux. As device is pretty slow, I've pulled one drive out of array, hoping to populate it with ...
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I can't access my LVM partition after RAID recovery

I need help after an accident with my RAID 5. I recreated it with: mdadm --verbose --create /dev/md2 --level=5 --chunk=64 --raid-devices=4 /dev/sdb4 /dev/sda4 /dev/sdd4 missing My array seems to ...
2
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1answer
26 views

re-assemble out-of-date raid5?

I need help with my raid5 after it crashed through bad sectors. Previously I could re-assemble it with # mdadm --assemble --force -v /dev/md0 /dev/sde1 /dev/sdf1 /dev/sdg1 /dev/sdh1 /dev/sdi1 but ...
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3answers
3k views

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 ...
2
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2answers
1k 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 ...