A linux utility used to manage software RAID devices.

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410 views

How do I keep mdadm from renaming my RAID array upon reboot?

So I have a system (a large instance running ubuntu-11.10 on Amazon EC2) where I've done something like mdadm --create bigdata --level 0 --raid-devices=2 /dev/xvdb /dev/xvdc I get a RAID device ...
2
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1answer
578 views

What was the default chunk size in previous versions of mdadm? Is there a way to set data/super offset? Trying to recreate a raid 5 md with all spares

I have a 6 device raid 5 array which had 1 disk go bad and then due to a power outage, the machine shutdown and when it started all the disks were showing up as spares with the following mdadm -E ...
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2answers
749 views

How to move Mdadm RAID drive (EBS based) to different AWS Instance

We have a media-rich web application that is hosted on AWS. We have several Web Servers and we have an NFS server. On the NFS server (Linux server) we have several EBS volumes that are mounted and ...
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2answers
1k views

Raid 5 with 4 disks on Debian automatically creates a spare drive

I'm trying to to create a RAID 5 with 4x 2TB disks on Debian 6. I followed the instructions from: http://zackreed.me/articles/38-software-raid-5-in-debian-with-mdadm I created the raid with following ...
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2answers
86 views

Raid array on partition bleeds through to block device

EDIT: It appears that this might be an inherent issue with the .9 superblock version. Figures that I would only be able to find these links after I posted here. ...
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2answers
1k views

Linux mdadm software RAID 6 - does it support bit corruption recovery?

Wikipedia says "RAID 2 is the only standard RAID level, other than some implementations of RAID 6, which can automatically recover accurate data from single-bit corruption in data." Does anyone know ...
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2answers
1k views

mdadm raid5 too slow when writing

I have set up a RAID5 array using 4 disk partition. All disks are 2TB. When the RAID5 array was initially syncing it was too slow. So I did a echo 32768 > /sys/block/md2/md/stripe_cache_size and ...
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2answers
671 views

strange mdadm behavior - on failing to create, md127 appears with “Device or resource busy” on freshly created partially zeroed partition

Problem: # ls /dev/md* /dev/md0 /dev/md1 # dd if=/dev/zero of=/dev/sdb3 bs=1M count=1 # dd if=/dev/zero of=/dev/sdd3 bs=1M count=1 # mdadm --zero-superblock /dev/sdb3 # mdadm --zero-superblock ...
6
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1answer
8k views

Ubuntu server, gpt partition table, mdadm, grub boot fail

Basic working system details: I used the Ubuntu 12.04 server CD to install a server. I have 4 disks. On all disks I did the following, similar to this howto : created a 2GB swap partition created ...
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0answers
940 views

Can't mount logical volume, RAID/MD/LVM problems

I have a file server with 48 2TB HDDs split across 2x 3ware 9650SE-24M8 RAID cards. Both cards have 24 drives in RAID 1+0. MD softraid is setup in raid 0 with the two RAID 1+0s making RAID 100. LVM2 ...
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1answer
749 views

MDADM not able to connect to EBS drives on Ubuntu 11.10

I have been using a raid.sh script [1] for over a year now and has never gave me trouble. I recently started moving from Ubuntu 10.04 machines on AWS to Ubuntu 11.10. I updated the raid.sh script from ...
2
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1answer
925 views

mdadm warning after apt-get upgrade - can't boot RAID

I'm running Ubuntu 12.04 precise. A recent apt-get upgrade ended successfully, but printed the following warning at the end: update-initramfs: Generating /boot/initrd.img-3.2.0-21-generic W: mdadm: ...
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1answer
169 views

Does linux software raid10 perform any data verification on each write?

I wand to find out is there any benefit in safety of storage data between manual sync(using cron & rsync) of two RAID0 volumes and RAID10 volume using Linux software raid. Does RAID10 preform any ...
2
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3answers
889 views

Can I convert a raid10 array to raid0?

I have created a raid10 array using mdadm. Metadata version is 1.2. I want to convert this to a raid0 array, is it possible? P.S. I am having terabytes of data, I want to avoid copying the data over. ...
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1answer
542 views

How to force mdadm to use udev device names rather than /dev/sdX

The question is mostly in the title already. mdadm and /proc/mdstat insist on listing md members by their "traditional" /dev/sdX names. What I want is for them to use the newer udev device names ...
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1answer
3k views

Build and migrated to software raid (mdadm) on GPT disk, now can't assemble array

mdadm, gpt issues, unrecognized partitions. Simplified question: How do I get mdadm to recognize GPT partitions? I have been attempting to convert/copy my Ubuntu 11.10 OS from a single drive to ...
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0answers
319 views

MD Raid can't be assembled

I was running a Raid5 with 3 disks at on my homeserver. But had some problems with the back-plane for the disks. The disks weren't detected reliable. So I replaced the back plane and the disks are now ...
2
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2answers
2k views

Cant boot newly created mdadm software raid in Debian linux squeeze

Hello I have very strange problem creating swraid on Debian Squeeze Linux. I started creating RAID1 from existing standard instalation of Debian on single drive. So I bought new drive and started ...
2
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2answers
494 views

mdadm failure detected on one partition

I received this rather nice email today suggesting one of the drives in a RAID1 array has failed. A Fail event had been detected on md device /dev/md4. It could be related to component device ...
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2answers
337 views

Relabeling of filesystems (SELinux) fails

After compiling the policy modules and re-compiling my core packages (Gentoo 32bit) I wanted to relabel the filesystems (via rlpkg -a -r) and packages but I get these error messages: Relabeling ...
2
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2answers
865 views

Move an existing RAID 5 array from Ubuntu to Gentoo

I have a 64-bit Ubuntu machine with a 4-disk RAID 5 using software raid (md). I've been able to boot an Ubuntu LiveCD and recognize the array with a simple mdadm -A /dev/md0. It was easy to mount ...
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0answers
813 views

mdadm raid1, [1/2] disks failed, safe to reboot?

I am seeing the following under /proc/mdstat Personalities : [raid1] md1 : active raid1 sda2[0](F) sdb2[1] 976554876 blocks super 1.1 [2/1] [_U] bitmap: 4/8 pages [16KB], 65536KB chunk md0 : active ...
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426 views

How do I create a RAID10 array using EBS on Amazon?

Basing this question on information I got in Why does df shows only half the size of a RAID10 array?, how should I create a RAID10 array using EBS volumes on Amazon, in a way that will not be ...
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0answers
260 views

After upgrade to SLES11 SP1 - LVM on top of software RAID5 not working anymore

On a system where I have been running OpenSuSE11.1 for some time I performed a fresh installation of SLES11 SP1. The system used a software RAID5 system on top of which an LVM was setup with a single ...
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2answers
2k views

apt-get update mdadm scary warnings

Just ran an apt-get update on one of my dedicated servers to be left with a relatively scary warning: Processing triggers for initramfs-tools ... update-initramfs: Generating ...
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1answer
510 views

mdadm: hot remove failed for…

My RAID1 is degraded and I need to replace /dev/sdb. However, I could mark /dev/sdb5 (in /dev/md1) as failed and removed it, but I can't do the same with /dev/sdb1 (/dev/md0 which is mounted on /): ...
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1answer
202 views

get mkfs.xfs options from existing xfs filesystem

I set up a new server last week, did some testing with different mkfs.xfs options on mdadm raid5, i finally found some statisfying mkfs options. Now i am about to set up a new server having exactly ...
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0answers
142 views

mdadm LBA mapping

I am trying to write a script similar to mdtrim (https://github.com/Cyberax/mdtrim) for a raid 0 software raid through mdadm. The mdtrim is for raid 1 only at the moment, and it works by writing a ...
4
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1answer
425 views

Debian installation on software RAID (lilo.conf configuration)

Debian installation program has created lilo.conf: boot=/dev/md1 root=/dev/md1 raid-extra-boot=mbr-only But when i configure lilo i usually put these lines disk=/dev/md1 sectors=63 heads=255 ...
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1answer
998 views

How to disable mdadm when running hardware RAID

My server Dell R210 runs a Debian squeeze with hardware RAID1 (H200) preconfigured. But I notice that there is mdadm running. Sometimes in backup, or in OS upgrade (to Debian 6.0.4), I have messages ...
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492 views

Rebuilt md raid 6 array now showing xfs errors. How bad is it?

We had a storage server with performance starting to be poor. When I installed Linux's smartutils, it found Device: /dev/sdm, 2 Offline uncorrectable sectors Since this was a rather large raid6 ...
5
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1answer
815 views

Use cases for “mdadm --create” vs. “mdadm --build”?

From the mdadm man page, --build section: This usage is similar to --create. The difference is that it creates a legacy array without a superblock. ^^ So no superblock with --build. 10-4. ...
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507 views

Cryptsetup device /dev/md0 is not a valid luks device

After reinstallation of my OS, I decide to manually assemble a RAID6 array. # mdadm --assemble --auto=yes --scan=auto /dev/md0 I don't exactly remember a message but programmdadm return a resizing ...
31
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4answers
12k views

Recover RAID 5 data after created new array instead of re-using

Folks please help - I am a newb with a major headache at hand (perfect storm situation). I have a 3 1tb hdd on my ubuntu 11.04 configured as software raid 5. The data had been copied weekly onto ...
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3answers
2k views

Creating a partitioned raid1 array for booting a debian squeeze system

I'd like to have the following raid1 (mirror) setup: /dev/md0 consists of /dev/sda and /dev/sdb I created this raid1 device using mdadm --create --verbose /dev/md0 --auto=yes --level=1 ...
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1answer
651 views

how to migrate lvm mirrorlog from physical partition

Output from: sudo lvs --all -o +devices root hp03 mwa-ao 18.62g root_mlog 100.00 root_mimage_0(0),root_mimage_1(0) ...
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2answers
901 views

Linux: very slow mdadm resync on raid 1

I'm trying to rsync a RAID 1 on a system with absolutely nothing running ( i've moved all services to another server ). So it's just me via ssh. For some reason, it's very slow: cat /proc/mdstat ...
4
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2answers
825 views

Slow md RAID-1 array

We have some problems with very slow disk response on our server. I checked iostat (iostat -d -x 30) and have some problems with its interpretation: Device: rrqm/s wrqm/s r/s w/s ...
5
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1answer
176 views

Recovering linux software RAID array without removing it's items

I have linux software raid (RAID10), md2 : active raid10 sda6[4](F) sdd5[3] sdc5[2] sdb6[1] 390620160 blocks 64K chunks 2 near-copies [4/3] [_UUU] which has degraded state. Can i start recovery ...
1
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1answer
2k views

Ubuntu EC2 Raid0 Ephemeral — SSH connection after reboot

First, I launch a fresh large instance using the Elestic AMI ami-c162a9a8. Initially, I run: df -h /dev/xvda1 9.9G 814M 8.6G 9% / udev 3.7G 4.0K 3.7G 1% /dev ...
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3answers
202 views

Linux software raid robustness

I have a 4 disk 5TB raid5 setup where a disk is showing signs of going down the drain. It is reporting media errors and from dmesg I can see that several read errors are corrected. smartctl does ...
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1answer
500 views

Ubuntu Server mdadm drbd ocfs2 kvm hangs under heavy file reading

I have deployed four ubuntu 10.04 server. They are coupled two by two in a cluster scenario. on both sides we have software raid1 disks, drbd8 and OCFS2 and on top of it some kvm machines run with ...
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1answer
837 views

Unresponsive mdadm

I have a raid 5 mdadm raid array set up with 6 drives and a hot spare on an Ubuntu 11 server. There are a couple samba shares on the drive, and until today, they were working well. A couple hours ago ...
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1answer
199 views

mdadm scheduled check [closed]

I now have several devices that start the monthly mdadm scheduled check. I can let them all run monthly, stagger the checks, or disable them completely. I had the misfortune of several disks turning ...
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0answers
232 views

Reassemble RAID 10 array without losing data

I have a RAID 10 array created from 4 iSCSI devices. This morning I temporarily lost connectivity to 2 of those drives. And it was long enough for mdadm to take them out of the array. Unfortunately ...
0
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1answer
863 views

Linux: Rebuilding MD-RAID 1 array when one drive has been out of array for awhile

About a month and a half ago I noticed that the two hard drives in a (OpenSuSE 11.3) server were dying. Guessing based off the SMART data, I replaced /dev/sdb first; to do this I removed the drive ...
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3answers
2k views

Why is my mdadm raid-1 recovery so slow?

On a system I'm running Ubuntu 10.04. My raid-1 restore started out fast but quickly became ridiculously slow (at this rate the restore will take 150 days!): dimmer@paimon:~$ cat /proc/mdstat ...
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1answer
357 views

Linear mode to RAID 1 migration

Consider creating a linear mode RAID with single disk(more disks may be added later). #echo y | mdadm --create /dev/md0 --level=linear --raid-disk=1 /dev/sda1 --force Now consider another partition ...
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3answers
5k views

How to resize RAID1 array with mdadm?

I've running Ubuntu 11.04 (kernel 2.6.38-11). I replaced 2x160GB with 2x500GB drives. They are configured as RAID1. The partition tables show the right sizes. Here's sfdisk: # sfdisk -d /dev/sdb # ...
0
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1answer
509 views

identifying and cloning the superblock of a raid0 mdadm v0.90 array

/dev/sdb13 174706938 976768064 401030563+ fd Linux raid autodetect The size of that partition is 802061126 sectors. From what i read - mdadm should have placed the actual superblock ...