All Questions
Tagged with mdadm software-raid
105
questions
2
votes
1
answer
4k
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 ...
- 441
1
vote
0
answers
100
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 ...
- 111
0
votes
1
answer
458
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 ...
- 185
2
votes
2
answers
3k
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] [...
- 63
1
vote
2
answers
3k
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 ...
- 21
0
votes
1
answer
2k
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 ...
- 103
1
vote
1
answer
2k
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 ...
- 121
4
votes
1
answer
4k
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 grow-...
- 193
5
votes
4
answers
15k
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 /...
- 51
1
vote
1
answer
4k
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 ...
- 1,260
1
vote
1
answer
2k
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 ...
- 235
6
votes
1
answer
504
views
mdadm: Win7-install created a boot partition on one of my RAID6 drives. How to rebuild?
My problem happened when I attempted to install Windows 7 on it's own SSD. The Linux OS I used which has knowledge of the software RAID system is on a SSD that I disconnected prior to the install. ...
- 191
2
votes
0
answers
885
views
Redundancy: LVM+mdadm or LVM internal RAID
The task is to create LVM storage for virtual machine images. So LVM will be used in any case.
There are two ways LVM providing redundancy:
block mirroring
lvcreate -m 1 --mirrorlog mirrored -n ...
- 121
0
votes
0
answers
511
views
Hybrid Raid-1 HDD + SSD -- Write Intent Bitmap
I am currently running a laptop with 1 HDD and 1SSD.
I currently am using mdadm to put some partitions in a raid 1 configuration with --perfer-write set on the HDD. I have this working correctly ...
- 229
2
votes
1
answer
4k
views
Understanding /proc/mdstat [U_] VS [_U]
My server is set up with raid1. A few nights ago sda fell out completely and data was corrupted. I replaced the drive, cloned the partition table and added the respective arrays. While adding sda3 (...
- 23
1
vote
0
answers
77
views
Is there a safe way to move a partition beneath a linux software RAID5 using mdadm?
Suppose, for example, that you have a RAID5 across multiple disks and you would like to retire the oldest of the disks and replace it with something from this decade. I know I can fail the partition ...
- 372
0
votes
1
answer
1k
views
Recover software RAID
I built a RAID-1 with two hard drives using mdadm. Command used was:
mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb /dev/sdc
it went fine, I create partition table and partitions in it, ...
- 101
0
votes
1
answer
826
views
Adding sda1 vs. sda to a linux software raid
I'm running a Linux md software RAID 6 on several USB hard-drives. Each drive is partitioned to contain one partition of type fd (linux raid). My RAID is built on these partitions, i.e. it uses sda1, ...
- 1,041
2
votes
1
answer
6k
views
Assembling an mdadm array with "possibly out of date" disks
I've recently moved house and have had some power problems after switching on my file server that's using a mdadm RAID5 set up. The file system I'm using is ext4.
It seems that at some point two (of ...
- 21
1
vote
0
answers
120
views
erased md0, md1 and can't recreate them
I previously had a working RAID 1 array. I think as a result of running grub-install /dev/sdb and grub-install /dev/sdc I somehow wiped my computer of md0 and md1.
I need to set them up again. When ...
- 218
3
votes
1
answer
2k
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]
...
- 275
1
vote
0
answers
548
views
Is `dmsetup remove` safe with respect to contained data?
I have a "lost" SW RAID array as described in this question: https://askubuntu.com/questions/311024/raid1-array-lost-after-upgrade-from-ubuntu-11-10-to-13-04. I have now identified a way to mount one ...
- 939
3
votes
1
answer
2k
views
Documentation for mdadm bad block support
I've read a bit about that mdadm (and the kernel) now have bad block support but I am having a hard time finding any useful documentation on this subject.
Is the bad block list for disk X duplicated ...
- 1,260
1
vote
0
answers
404
views
Upon reboot, Linux software raid fails to include one device of a RAID1 array
One of my four Linux software raid arrays drops one of its two devices when I reboot my system. The other three arrays work fine. I am running RAID1 on kernel version 2.6.32-5-amd64 (Debian Squeeze). ...
- 111
5
votes
2
answers
11k
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 ...
- 24.4k
0
votes
2
answers
216
views
Writing to a specific drive with software RAID4 on Linux
Edited to reflect conclusions from comments:
I want to construct a software RAID-like array with 2 storage devices plus one parity device, where the parity device maintains the XOR of the two other ...
- 125
34
votes
3
answers
207k
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
...
- 2,607
5
votes
0
answers
2k
views
mdadm RAID monitoring no DegradedArray email
So, I have a couple of MDADM RAID arrays and I want to set up monitoring with email notifications for drive failures through sSMTP but I can't seem to get it working.
The system in question is a ...
- 171
0
votes
1
answer
2k
views
Adjusting mdadm priority on Ubuntu
I have Ubuntu 12.04 running on my new server, and it is setup to run off of one drive, then 2 drives that are mirrored using mdadm. When streaming files or media from it, it is extremely slow. I was ...
- 24.4k
2
votes
2
answers
1k
views
Why make a partition at all for mdadm/raid?
i have 4 disks, sd[a,b,f,g] of various sizes that I want to 'merge' together. I am using mdadm to achieve this.
my question is, what's the difference between --
mdadm --create /dev/md0 --level=...
2
votes
1
answer
6k
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 ...
- 361
2
votes
1
answer
5k
views
Degraded RAID5 and no md superblock on one of remaining drive
This is actually on a QNAP TS-509 NAS. The RAID is basically a Linux RAID.
The NAS was configured with RAID 5 with 5 drives (/md0 with /dev/sd[abcde]3). At some point, /dev/sde failed and drive was ...
- 23
1
vote
1
answer
812
views
how to boot without assemblying raid arrays (or assembling them correctly)
I had one debian 6 system with two harddisks on raid1 set up via mdadm. built on simple partitions (/dev/sdb3, /dev/sdc3). at least on the old system, everything is tied up via UUIDs.
then i inserted ...
- 5,021
0
votes
0
answers
70
views
Do a Re-Build During a Re-Shape?
On my Linux software RAID 6 array, I'm currently mid-reshape and 2 drives have been marked as failed. I've swapped them out and added new ones to the array, which are currently marked as spares. The ...
- 858
0
votes
1
answer
159
views
Linux RAID Re-Shape Stopped
For the past 8 hours my mdadm re-shape process has been stuck. The output is:
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath]
md0 : active raid6 sdo[11] sdn[12]...
- 858
1
vote
1
answer
9k
views
How can one setup RAID 1 in Linux Mint 13?
I am trying to setup a Linux Mint 13 system using mdadm, with 2 1TB hard drives for a software mirror. I have tried following instructions found for Linux Mint 12, but the instructions fail to mention ...
- 24.4k
1
vote
1
answer
2k
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 ...
- 338
2
votes
2
answers
20k
views
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 ...
- 2,607
0
votes
1
answer
2k
views
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 ...
- 211
11
votes
3
answers
16k
views
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 ...
- 60.3k
9
votes
3
answers
4k
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?
- 740
2
votes
0
answers
3k
views
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 ...
- 456
0
votes
1
answer
229
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.
- 103
8
votes
3
answers
21k
views
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 ...
- 972
1
vote
1
answer
2k
views
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 ...
- 111
1
vote
1
answer
959
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 ...
- 311
28
votes
4
answers
65k
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 ...
- 1,469
2
votes
2
answers
1k
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, ...
- 121
2
votes
2
answers
423
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 ...
- 21
8
votes
3
answers
7k
views
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 ...
- 81