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4
votes
3answers
3k views

lost superblock in md raid

Issue on Red Hat Linux 5. Due to some miscommunication two LUNs in our environment were enlarged from 1.2 TB to 1.7 TB. Now, after a reboot, mdadm does not find the superblocks to build the array ...
4
votes
2answers
7k views

How do I recover files from a single degraded mdadm raid1 drive? “not enough to start the array”

Given a single raid1 drive in degraded/rebuilding state, can it be force mounted? I'd like to recover all the files before undertaking the dangerous operation of pairing it and rebuilding. As far as ...
1
vote
0answers
504 views

After ubuntu install + software raid 0 config, we see: rejecting I/O to offline device

I'm trying to pin down what this error rejecting I/O to offline device is, as seen towards the end of this syslog. Ideas: Problem with RAID-0 configuration (we have 2 4TB disks in RAID-0 and I do ...
1
vote
2answers
442 views

Migrate an entire volume group LVM2 to RAID5

I have a Virtual Host server build with Ubuntu and Xen SO Ubuntu 12.04.1 LTS 64Bits xen-hypervisor-4.1 Disk Hitachi SAS 15K 147GB (x2) in a Volume group sda1 1GB /boot sda2 146GB lvm sdb1 ...
1
vote
1answer
142 views

Can I move an existing Debian installation to a RAID5?

I put myself a small NAS together, to experiment a bit with raid. I have a working RAID 5 array using mdadm under Debian 6 ("squeeze"). I installed GRUB and Debian to an USB stick, since I was not ...
0
votes
1answer
239 views

Can I configure software RAID on an existing server without losing the existing partition?

I've got an existing server with 1 disk and Ubuntu 12.10 installed and running. I want to add a 2nd disk and configure RAID 0 across the two disks using Ubuntu's software RAID. Can I do this ...
1
vote
0answers
556 views

Installing 12.04LTS Server on a Fake RAID10

Scenario Install Ubuntu 12.04LTS Server on a RAID10 with boot on a RAID1. 4 - 2Tb SATA Hard Drives 3 Partitions (/boot, /, and swap) boot (256Mb from each disk) setup in RAID1 /dev/md0 partition ...
2
votes
0answers
419 views

Disable RAID auto detect at runtime

In Linux, I'm partitioning two disks for RAID1 with fdisk. The first disk partitioning succedes, but the second fail because the raid starts automatically and occupy also the second disk (why? it ...
2
votes
2answers
473 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
24k 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
481 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
583 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
147 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
150 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
8k 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
4k 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
397 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
962 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
753 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
642 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
7k 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
283 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 ...
7
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
295 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
7k 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
284 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 ...
7
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
504 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: ...
9
votes
4answers
25k 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 ...
7
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
37k 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 ...
7
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
375 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
566 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
244 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 ...