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2
votes
2answers
419 views

How does mdraid resync work?

I have two drives in a mirror (linux sw raid/mdadm); one drive somehow left the mirror in the past and its content is now several days old. At this moment, I'm using degraded mirror (with one drive ...
2
votes
2answers
1k views

Unable to rename a RAID device: stuck with /dev/md126

I had a fully working server. I booted with SystemRescueCD, without writing anything. I didn't even mounted a partition. Then rebooted the server. The server no longer boot correctly because some ...
6
votes
3answers
19k views

How to mount/recover data on a disk that was part of a mdadm raid 1 on another machine?

Some background The disk itself was "worked on" by a friend and is said to be still intact, undamaged and still mountable/recoverable The disk was part of a software raid 1 on Ubuntu 12.04 The other ...
9
votes
1answer
442 views

How do I recover a broken software RAID5 array?

Ack, I think I screwed up bad. I had a power failure on a RAID5 array which caused the metadata to be inconsistent between drives. I followed the advice here except a case of fat fingers caused me to ...
1
vote
2answers
485 views

Can I mount a microsoft mirrored dynamic disk?

I'm testing out sw raid in windows 7, but I almost always use linux and I would like to know if it's possible to mount such a mirrored dynamic disk. I can already mount each members separatly but ...
5
votes
1answer
1k views

degraded software raid boot

I've installed Ubuntu 12.04.1 in a new server and set up the 4 hard drives with 3 RAID 1 devices, the configuration is such that the first two drives have md0 (swap space) and md1 (/) with the third ...
3
votes
2answers
140 views

RAID Lag-Behind Burst Write

I would like to setup RAID1 so that a ramdisk in the RAID configuration has occasional synchronisation with a physical disk (that is very battery intensive to run, so I hope to let it spinout). Is ...
2
votes
2answers
2k views

Mixing 4k/512 drives with ZFS (FreeNAS)

I have the following drives: Seagate Barracuda ST3200054AS WDC WD20EADS-00S2B0 Samsung HD204UI As far as I understand, the first are ordinary 512 drives while the last is 4096 (Advanced format). ...
1
vote
0answers
145 views

Selective stripping on RAID-0 with mdadm [closed]

With mdadm one can create a raid with a fixed chunk. I am trying to have a line by line stripping of a file. In fact, I'd like my files to have there lines repartitioned across the RAID. I am ...
11
votes
4answers
7k views

Linux - Repairing bad blocks on a RAID1 array with GPT

The tl;dr: how would I go about fixing a bad block on 1 disk in a RAID1 array? But please read this whole thing for what I've tried already and possible errors in my methods. I've tried to be as ...
4
votes
1answer
1k views

RAID 10 can not be started

I have a RAID 10 array managed with mdadm which has failed . The symptom was that X has crashed and I was unable to logon from the terminal. I have restarted the computer and /dev/md1 did not start. ...
9
votes
2answers
3k views

Grow/resize RAID when upgrading visible size of disks

I originally created a software RAID using a controller that could only address 2TB per disk. The disks are 3 TB disks. It worked fine, but only used the first 2TB of each disk. I have now changed ...
2
votes
1answer
377 views

“error: no such device” at boot in Ubuntu Server 11.10 with Raid1

I have a configuration of 4 HDD's as Raid1 2 pairs of 2 HDD's. First Raid1 pair is for system, so I just made an 40GB space for swap, and the rest of it for the root, the second pair of Raid1 is for ...
2
votes
1answer
907 views

mdadm raid0 with disks of different size?

Currently I'm using LVM just to merge a few disks of different size. I want to know if it is possible to use mdadm with stripes instead of LVM? Will it give me additional performance? Will it use ...
1
vote
1answer
709 views

How do I attach my LVM RAID's to a new Ubuntu install?

I have an Ubuntu 9 Desktop system that I mainly use as a media server. I have a 2TB RAID5 and a 500GB RAID1, both using LVM. The OS drive is a 4GB CompactFlash card which has finally run out of space. ...
1
vote
2answers
617 views

Software raid + separate partitions?

I have setup software RAID1-arrays using two 250GB harddrives. There's two arrays - one named md0 in which the system is kept and the other, md1 works as swap: # cat /proc/mdstat md0 : active raid1 ...
3
votes
2answers
6k views

Does Grub2 support putting /boot on a RAID5 partition?

It looks like currently most OS installers insist on putting /boot on a non-RAID partition (or the kind of RAID1 partition that "looks like" a non-RAID partition), even the installers that support ...
2
votes
3answers
1k views

Advantages/Disadvantages of installing GRUB on a software RAID?

What Advantages are there to installing GRUB on a software RAID-1? What Disadvantages are there to installing GRUB on a software RAID-1? I ask this because most tutorials/help sections seems to ...
2
votes
1answer
271 views

Make Software raid of kernel use dedicated core of cpu

I am sure this is more of a question related to approach than a tech-how-to. I have 2 processors, each with 2 cores on my machine. I have Software RAID (md0) configured using Linux kernel. Is it ...
6
votes
2answers
8k views

Is Grub installed to all the MBR of a RAID array by default by the Debian Installer?

If I use the Debian Stable (Squeeze) Installer to install Debian, booting from a RAID1 pair of drives, does it write grub to the MBR of both drives - if not, how should I best protect against a drive ...
1
vote
2answers
276 views

Copying linux install from non-RAID/x86 to RAID/x86-64

I'm copying an Ubuntu Server install from an x86 machine with a single hard disk to a new machine with x64 and two identical disks. Two partitions will span the new disks: One small-ish RAID1 for ...
3
votes
3answers
6k views

Grub2 RAID /boot

I'm using Gentoo on my HomeServer. My HDDs are raid1 mirrored with mdadm. My problem is how to boot the /boot partition correct? /dev/md1 consists of /dev/sdc2 & /dev/sdd2 mounted on /boot In ...
3
votes
2answers
265 views

raid 1/LVM at the level of directories (aka mknodding a directory)

I just experienced data loss, so I am interested in some form of data duplication. I was thinking of mdadm and companions to raid 1 through software. However, I just want a given, not too big ...
6
votes
1answer
11k views

mdadm raid1 and what chunksize (or blocksize) on 4k drives?

I want to use two 3 TB drives in a mdadm raid1 setup (using Debian Sequeeze). The drives use 4k hardware sectors instead of the traditional 512 byte ones. I am a bit confused because on the one hand ...
1
vote
1answer
490 views

mounting an encrypted dm-raid partition on login

I have a dm-raid1 with a LUKS encrypted partition md0 on it and I would like it to be mounted automatically when I login, using pam_mount. So far I have configured the pam_mount.conf.xml as follows: ...
7
votes
3answers
21k views

lvm devices under /dev/mapper missing

I'm using Debian squeeze, and running LVM on top of software RAID 1. I just accidentally just discovered that most of the links under /dev/mapper are missing, though my system seems to be still ...
6
votes
2answers
5k views

How to raid-mirror existing root partition?

I'd like to mirror my existing root (and only) partition on an SSD to another disk. It should be a sort of RAID-1, just asymmetric*. I know there's the option mdadm --write-behind, which should do it. ...
18
votes
2answers
35k views

How to recover a crashed Linux md RAID5 array?

Some time ago I had a RAID5 system at home. One of the 4 disks failed but after removing and putting it back it seemed to be OK so I started a resync. When it finished I realized, to my horror, that 3 ...
6
votes
1answer
2k views

mdadm Raid5 gives spares missing events

I succesfully builded up a raid5 array on debian testing (Wheezy). As the manpages and further tell, the array would be created as an out of sync array with just a new spare injected to be repaired. ...
6
votes
2answers
2k views

Will the system make sure that mdadm is sync-ed before completing a reboot?

This is a follow up to my crazy mdadm problem. I'm trying to figure out what might have caused sda to get out of sync in the first place. The only thing I can think of is that I had just run a bunch ...
3
votes
1answer
1k views

installing grub 2 on mdadm, which device?

when installing grub(2) to mdadm devices are you supposed to install it to /dev/sdX or /dev/mdX?
2
votes
1answer
361 views

Drive was unable to assemble into the array

I ran mdadm -A /dev/md0 /dev/sda1 /dev/sdb1 Only /dev/sdb1 was loaded into the array though. I have a few more arrays on the same two drives too. Each time the partition on sda failed. dmesg told ...
4
votes
2answers
2k views

what is commit=0 for ext4? does mdadm not support it?

I see this in my dmesg log EXT4-fs (md1): re-mounted. Opts: commit=0 EXT4-fs (md2): re-mounted. Opts: commit=0 EXT4-fs (md3): re-mounted. Opts: commit=0 I think that means that dealloc is disabled? ...
7
votes
2answers
542 views

In place upgrade of a software raid 5 array

I run a software raid array for my backups, but my data has outgrown capacity. considering I have a full 2.4TB array with 5*600GB drives and also have 5*2TB drives I would like to swap in. What ...
5
votes
3answers
241 views

RAID 1 in linux

I'd like to setup RAID 1 with two drives in linux. I don't have a hardware RAID controller and don't want to buy one, so what is the best software RAID option for linux? Note: If it makes a ...