A linux utility used to manage software RAID devices.

learn more… | top users | synonyms

0
votes
1answer
633 views

How do I get rid of my duplicate GRUB entries? (Ubuntu 12.10, RAID1)

I have a Dell R300 machine running Ubuntu 12.10: $ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 12.10 Release: 12.10 Codename: quantal $ uname -a ...
3
votes
1answer
254 views

Cannot get at data in my NAS

I've got a bit of an issue that I'm hoping you can help me with. I have an Iomega ix4 as my NAS. This runs Linux and each drive in the box has 2 partitions: one for the OS and RAID info, and the ...
1
vote
1answer
831 views

How to detect hard disk failure?

So, one of my servers has a hard disk failure. It's running software RAID, the system locked up and according to /proc/mdstat (and /var/log/messages), it's really down: Personalities : [raid1] md2 : ...
2
votes
2answers
724 views

mdadm - Recovering a 'split' RAID1 array

I have two drives that used to be part of a single RAID1 volume but it appears that one of them went offline for some time, something I've noticed just now when I rebooted my system. I now seem to ...
4
votes
1answer
1k views

mdadm+zfs vs mdadm+lvm

This may be a naive question since I'm new to this and I cannot find any results about mdadm+zfs, but after some testing it seems it might work: The use case is a server with RAID6 for some data that ...
1
vote
1answer
905 views

Linux software RAID6: 3 drives offline - how to force online?

This is similar to 3 drives fell out of Raid6 mdadm - rebuilding? except that it is not due to a failing cable. Instead the 3rd drive fell offline during rebuild of another drive. The drive failed ...
2
votes
2answers
266 views

Shell Script To Monitor Completion of RAID Assembly

How can I pause execution of my shell script after calling the following command until the raid array has been assembled? From what I understand, this is an asynchronous process and status of the ...
3
votes
2answers
776 views

Linux Software RAID1 Rebuild Completes, but after reboot, its degraded again

I have been beating my head with an issue here, and I'm now turning to the internet for help. I have a system running Mandrake Linux, with the following configuration: /dev/hda - This is a IDE ...
2
votes
1answer
293 views

How to get started troubleshooting Linux mdadm raid10 write performance?

Using Linux mdadm, I've setup a six disk raid10,f2 array. I'm using 7200RPM SATA drives. The biggest load I am worried about is recording four streams of live video (worst case of 20Mbits each, final ...
1
vote
1answer
653 views

Controlling mdadm faulty disk rebuild order in RAID 10 array

I have a Linux mdadm RAID 10 array comprising of 6 (SATA) disks configured with n2 copies. While pulling out one disk, another one in another mirror pair failed. Leaving me with: $ cat /proc/mdstat ...
6
votes
2answers
360 views

RAID1: Which disk will be mirrored?

How does a RAID1 system determine which disk to use as the source and which disk to use as the destination when mirroring? Assume for instance the following scenario: A RAID1 array is created with ...
0
votes
2answers
644 views

Recovering a mdadm+lvm+ext4 partition with read error

One of disks in my NAS has failed. The NAS is running Linux, and it uses mdadm + LVM technology for its filesystems. I do have backup for most of the contents, but not for the very last changes, and ...
1
vote
2answers
616 views

Risky to have RAID5 with 3x3TB drives? What alternatives should I be considering?

A drive dropped out of my raid 5 array yesterday. It looks like the reason was due to a bad controller so I switched it out and attempted to re-add the drive but mdadm claimed it couldn't do it. So I ...
1
vote
1answer
639 views

raid10 in mdadm reports incorrect “Used Dev Size”

I previously had a raid5 with mdadm using four 2TB drives. I've recently disassembled the raid and created a raid10 with six 2TB drives, but mdadm --detail is showing "Used Dev Size" as only 2TB (the ...
1
vote
0answers
265 views

RAID disk not booting

my hosting facility replaced disk /dev/sda for me and I've added it to the RAID via sgdisk -R /dev/sda /dev/sdb mdadm /dev/md0 -a /dev/sda1 mdadm /dev/md1 -a /dev/sda2 mdadm /dev/md2 -a /dev/sda3 ...
1
vote
1answer
380 views

mdadm superblock hiding/shadowing partition

Short version: Is it safe to do mdadm --zero-superblock /dev/sdd on a disk with a partition (dev/sdd1), filesystem and data? Will the partition be mountable and the data still there? Longer ...
1
vote
1answer
3k views

Creating Persistent Drive Labels With UDEV Using /dev/disk/by-path

I have a new BackBlaze Pod (BackBlaze Pod 2.0). It has 45 3TB drives and they when I first set it up they were labeled /dev/sda through /dev/sdz and /dev/sdaa through /dev/sdas. I used mdadm to ...
3
votes
1answer
482 views

mdadm kernel log messages explained

Welcome. I try to recover from linux software raid failure. I am in a process of recreating the superblocks based on a syslog from the system when it was healthy. The log speaks about 2 md devices, ...
1
vote
1answer
694 views

What parameters to mdadm, to re-create md device with payload starting at 0x22000 position on backing storage?

I try to recover from mdadm raid disaster, which happened when moving from ubuntu server 10.04 to 12.04. I know the correct order of devices from dmesg log, but given this information, I still cannot ...
0
votes
1answer
92 views

How many really distinct permutations of volumes are in mdadm raid5 degraded array?

I'm attempting to recover from a failure of my raid volume after upgrade from ubuntu 10.04 to 12.04. I've tried re-creating the array in any combination of 5 elementary volumes with one replaced ...
1
vote
1answer
81 views

DegradedArray event on /dev/md0 without actually having a RAID

Since I upgraded from Ubuntu LTS 10 to LTS 12, I have been getting error messages like: N 60 mdadm monitoring Mon Sep 3 06:38 31/1022 DegradedArray event on ...
1
vote
0answers
176 views

four-disk md raid10-far can be assembled and ran as “clean, degraded” with only 2 disks. Bug or i'm missing something?

Today i was solving raid failure on raid10-far with four disks. One disk failed and another wasn't re-added after a hard reboot. The mdadm -D was reporting it's clean and running with only two out of ...
1
vote
2answers
455 views

Must partprobe before using drive?

This is a followup question to Cannot mount /dev/sdc1 on Debian 5.0, special device /dev/sdc1 doesn't exist Basically, I have 6 SATA hard drives in a machine and I'm trying to create a RAID6 ...
2
votes
0answers
2k views

Calculating correct stripe size for Linux mdadm RAID10 arrays in “far” layout

I'm creating RAID10 array from 6 drives. When created in near layout, e.g. mdadm --create /dev/md2 --chunk=64 --level=10 --raid-devices=6 --layout=n2 /dev/sda1 ... Checking stripe size as ...
0
votes
1answer
399 views

mdadm: superblock on /dev/sdd1 doesn't match others - assembly aborted

OS: Debian Squeeze Kernel: 2.6.32-5-amd64 mdadm version: 3.1.4 (31 August 2010) mdarrays md1 = raid1 (this is working) (devices: /dev/sd[fg]1) md0 = raid6 (previously raid5, ...
1
vote
2answers
334 views

Ubuntu 12.04 Server Software RAID1 - Faulty Spare - Smart Output Passed - Confused

I think I'm having an issue with one of the hard drives on my array and I'm just trying to troubleshoot what's happening. Its saying Faulty Spare and then after reboot it just says removed: ...
1
vote
1answer
909 views

mdadm and blkid give different uuid

We recently replaced a hard disk in a server and reinstalled the operating system (Centos 6) The raid rebuilds itself every boot; /dev/md2 is losing a disk each time apparently. Always the same ...
4
votes
2answers
3k views

Can't resize2fs - combination of flex_bg and !resize_inode

I recently set up my first software raid with mdadm and after adding more disks to the raid I am unable to resize the filesystem to the full size of the raid. I created a single (~16TB) filesystem on ...
1
vote
1answer
730 views

Rebuild Linux raid1 after os reinstall

I have 4 disks in my server. sda and sdb were combined to RAID1 and had the operating system. sdc and sdd were a second RAID1 device that had a single volume group with a bunch of LVMs. sdd died so ...
1
vote
1answer
190 views

mdadm update time and resync

I detached one half of my linux md raid1 (--fail --remove) to do some potentially risky filesystem work, to be sure I had a good copy on hand if things went bad. Things went well, and now I want to ...
4
votes
3answers
1k views

mdadm RAID 5 Failed with 2 Drives while rebuilding

I have a RAID 5 array with 3 Disks (sdb sdc sdd) Over last weekend I was prompted that sdd had failed. so replaced the drive, added it back into the array and let it rebuild (1.5TB) It stopped at ...
3
votes
1answer
2k views

Linux raid controller (LVM/MDADM)

Today I'm in a very bad place. A production raid array went down. The controller failed. After unmounting the file systems and killing all processes, I changed the hardware controller. On restarting ...
2
votes
2answers
176 views

Production Disk Failure - Lucky it's sunday and out of hours (mdadm raid 5)

I have a production raid array that has hit problems. Luckily when I configured it I assigned a hot spare. Here is what the status looks like now: mdadm --detail /dev/md2 /dev/md2: Version : ...
0
votes
1answer
209 views

Optimized raid 0 configuration for Amazon EC2 hi1.4xlarge

How do I know what is the best configuration for RAID 0 (mdadm create options) between the to ephemeral drives?
-1
votes
2answers
1k views

Determining the software RAID configuration on an Ubuntu server

I have an Ubuntu box which was installed by an admin who is not with me now. I have no information on how he configured the RAID and neither no experience on setting up a software RAID on Linux ...
4
votes
1answer
385 views

3 drives fell out of Raid6 mdadm - rebuilding?

i had an mdadm raid6 array with 13x1TB drives. Within 10 minutes 3 of these drives fell out of the array... we assume bad cable to the controller card and replaced, however now we need to get the ...
0
votes
2answers
4k views

how to know what is disk uuid for md raid1 and hdparm?

ive got md0 (raid 1) array and want to make write cache off on them during system boot (ubuntu 12.04 server). md0: /dev/sda /dev/sdc blkid: /dev/sda: UUID="3e502de5-696d-f4b4-470e-XXX" ...
0
votes
1answer
572 views

Rebuild doesn't finish after raid1 disk replacement

In one of our servers one of the disk failed, no worries it happens all the time, we replaced the bad disk following the usual procedure but then ... 'the horror', after adding a new disk one of the ...
3
votes
2answers
493 views

Reading off of MDADM drives after server died

I had a 2-drive RAID-1 array running on ubuntu, which I had forgotten about. The host I was running them on is now dead, leaving me with these two disks. How can I get data off of them? If I dump ...
2
votes
1answer
358 views

LVM incorrectly reported missing after power failure

We have had a major power failure in the data-center. We are using a set of servers for our storage needs. The main server has several pairs of disks mirrored with mdadm. The resulting /dev/mdX are ...
1
vote
1answer
459 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
votes
1answer
647 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 ...
0
votes
2answers
1k 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 ...
3
votes
2answers
2k 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 ...
1
vote
2answers
89 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. ...
9
votes
2answers
2k 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 ...
0
votes
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 ...
0
votes
2answers
846 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
votes
1answer
10k 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 ...
1
vote
1answer
945 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 ...