A linux utility used to manage software RAID devices.

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2
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1answer
9 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re-assemble out-of-date raid5?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 ...
24
votes
5answers
46k views

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 ...
6
votes
3answers
1k 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 ...
19
votes
9answers
26k views

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 ...
2
votes
2answers
963 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 ...
0
votes
0answers
37 views

OwnCloud - storing data on RAID array

I have a server running Ubuntu Server 14.10 LTS 64bit. It has an O/S drive, and then a data RAID-1 array mounted under /srv/storage I've installed OwnCloud server using the default sqlite DB. I've ...
4
votes
4answers
2k views

Need to find which drives are mirrored within RAID-10 array

I have a home media server running on openSUSE 12.2. I'm using eight 2TB drives in a RAID-10 configuration. I deliberately bought two different types of drives: four Seagate Barracuda Green and four ...
0
votes
0answers
12 views

Ubuntu Server 12.04. Software RAID1 state degraded with a spare drive

After a disk failure, this is the output of mdadm --detail /dev/md2 in my Ubuntu Server 12.04: /dev/md2: Version : 1.2 Creation Time : Thu Dec 27 10:51:42 2012 Raid Level : raid1 Array Size : ...
0
votes
1answer
13 views

Error RAID1 but can't seem to find where the error is?

I'm having trouble figuring out where the problem is. I'm seeing my two drives... I removed a failed drive and installed an empty one. Thought I added it to the raid and it said it was rebuilding. ...
0
votes
1answer
24 views

Linux soft RAID5 array with mismatched events won't assemble

The last three nights, one of my USB controllers has gone offline in the middle of the night, knocking 4 of my 8 disks offline. The first two times, I was able to get it working again with mdadm -A ...
0
votes
1answer
2k 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 ...
0
votes
1answer
47 views

upgrade (software) RAID 1 capacity

I am upgrading a software RAID 1 array (/dev/md0) from 2TB drives (sda and sdb) to 4TB (sdc and sdd). Straight forward; ext3, single partition, no MBR, no LVM. In the end, I would like to have two ...
0
votes
0answers
155 views

Reboot causes DegradedArray event on Raspberry Pi

I tried to setup a RAID1 with two external SATA drives connected over USB to my Raspberry Pi (Model B+ running Raspbian Wheezy). The disks are both new Western Digital WD20EZRX drives with 2TB ...
2
votes
0answers
113 views

how to trim the SSD disk of an hybrid Linux soft RAID?

We are considering implementing an Hybrid Linux Raid with SSD+HD by using the "writemostly" flag that supposedly makes the raid write further to the HD than to SSD while maintaining the benefits of ...
8
votes
3answers
32k views

How do I reactivate my MDADM RAID5 array?

I've just moved house which involved dismantling my server and re-connecting it. Since doing so, one of my MDADM RAID5 arrays is appearing as inactive: root@mserver:/tmp# cat /proc/mdstat ...
1
vote
2answers
472 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 ...
0
votes
1answer
66 views

mdadm --examine displays something different than --detail

Who should I trust to fill my /etc/mdadm/mdadm.conf ? mdadm --examine --scan returns /dev/md/0 while obviously it's /dev/md0 that is currently rebuilding What should I put in my /etc/mdadm/mdadm.conf ...
1
vote
1answer
95 views

Functional MD complex RAID10 suddenly marks all drives as spares

This morning during a long ~1.5TB read operation sending data to an NFS client, my md complex-RAID10 array spontaneously stopped, then dropped four members for being "non-fresh" and failed to start ...
0
votes
0answers
32 views

Updated CentOS kernel to 2.6.32, system won't boot because mdadm array can't be checked/isn't mounted

Just updated a FreePBX system, kernel is now at 2.6.32. Have two RAID 0 arrays that mdadm arranges in RAID 1. Worked fine up until this update, now I get fsck.ext4: No such file or directory while ...
5
votes
1answer
1k views

Does TRIM avoid the performance impact of mdadm RAID 1 on SSD?

It has already been mentioned in other questions that Red Hat recommends against using mdadm RAID 1 on SSD. Red Hat also warns that software RAID levels 1, 4, 5, and 6 are not recommended for use ...
1
vote
0answers
46 views

Growing an encrypted RAID5 array without causing alignment issues

Question Is there anyway to tell mdadm to make sure a certain logical sector on the RAID-device stays aligned to the beginning of a stripe when growing a RAID5 array? Problem My RAID5 is encrypted ...
0
votes
1answer
81 views

mdadm: Reactivating RAID6 array after improper shutdown

I have a seven-disk RAID6 array on a file server. The server experienced a crash and a hard reset was required, resulting in an improper shutdown. Note that I/O activity was likely occurring on the ...
0
votes
1answer
96 views

How to link a linux system to an existing RAID1 on 2 external hard drives?

I installed Debian Linux (Wheezy) on a small HDD, added two identical large (2TB) HDDs, and built a RAID1 (without using lvm), using mdadm. I have stored a large quantity of files on the RAID. I run ...
2
votes
2answers
258 views

Removing a disk from an Ubuntu mdadm RAID marks the array as inactive, instead of degraded

I'm setting up a mdadm raid 1 array on Ubuntu 14.10 under VirtualBox. Everything works fine: The raid 1 is set up with /dev/sdc1 and /dev/sdd1: Personalities : [linear] [multipath] [raid0] [raid1] ...
2
votes
1answer
8k 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 ...
1
vote
2answers
128 views

MDADM says can't assemble RAID5 because missing disks but all disks are there

To start this, I installed a SATA expansion card so I could get more Drives into the computer. I moved the RAID to the expansion card, after attempts failed to get the OS SSD onto them. There was a ...
1
vote
1answer
53 views

How to Create Virtual Block Devices

I want to create multiple virtual block devices like /dev/sda and then use them to create an md device for test purpose. I have mounted my root filesystem on /dev/sda1 and don't have extra space to ...
0
votes
1answer
60 views

Recovering software raid

I have a 3-disk software raid 5. Two disk appear to have failed at the same time; their number of Events is the same, while other third disk's is higher. I have copied all three disks into new ...
1
vote
0answers
35 views

Safe to blank MBR of a disk after adding it to an RAID1 array with mdadm?

I created a RAID1 array of two disks, /dev/sda and /dev/sdb, using mdadm. After several booting problems related to the BIOS and SATA/RAID controller of the board, I accidently created some new ...
1
vote
1answer
62 views

How to proceed after creating software RAID 1 array on Linux

So, I've created a RAID 1 array using two 500 GB hard drives. I used a Linux Mint Boot Disk, and then used mdadm to create the RAID 1 array using 2 hard drives, each which has a single primary ...
4
votes
1answer
320 views

HDDs occasionally “click” and dump this error

Every once in a while, my HDDs (6 1TB drives in a Linux md RAID-6 array) make a brief "click" sound, and I get this from dmesg. I don't really have any clue how to start diagnose this, or even how ...
0
votes
1answer
215 views

Cloning md partitions for recovery

I have a failed software RAID5 (3x500GB disks) that I'm trying to recover. I don't want to try some of the more risky steps on the actual disks, so I want to clone them to new partitions on a new 3TB ...
0
votes
1answer
240 views

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 : ...
2
votes
2answers
312 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 ...
11
votes
3answers
22k views

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 ...
0
votes
1answer
115 views

I reinstalled ubuntu and now I don't see my RAID drive

I originally had a Ubuntu 12.04 system with RAID5 array that I built using mdadm. Due to issues with graphics drivers, the 12.04 system crashed and I had to reinstall the operating system. After ...
1
vote
1answer
132 views

move mdadm raid to new system

Have a 4-drive Ubuntu mdadm raid in a system whose motherboard (ASUS N1996) failed permanently. I tried putting the 4 drives in another system with a different motherboard, but when it came up it ...
5
votes
1answer
3k views

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 ...
1
vote
1answer
571 views

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 ...
2
votes
1answer
385 views

MDADM RAID-0 does not increased size after grow on AWS Linux with EBS

I wanted to grew a Raid0 from 2 disks to 3 (each 1TB EBS on Amazon AWS) but the size did not change thereafter. The RAID started with two disks sdc and sdd and the new one was sdf. Here is the ...
2
votes
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 ...
2
votes
2answers
1k 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 ...
0
votes
2answers
888 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 ...
1
vote
2answers
1k views

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 ...
2
votes
3answers
1k 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?
1
vote
0answers
179 views

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 ...
1
vote
1answer
68 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 ...
0
votes
1answer
251 views

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 ...
2
votes
2answers
661 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 ...
0
votes
0answers
130 views

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: ...