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Questions tagged [mdadm]

A linux utility used to manage software RAID devices.

844 questions
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Slow disk I/O in KVM with LVM and md raid5

I have been battling with a kvm setup under debian for two weeks now, specifically with guest I/O disk performance. The system: -Supermicro 1018d-73mtf (X10SL7-F motherboard) -16GB ECC/UB -Intel Xeon E3-1240v3 -6xWD Red 750GB 6Gb/s On this i am…
FrontSlash
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How to get rid of a stubborn 'removed' device in mdadm

One of my server's drives failed and so I removed the failed drive from all three relevant arrays, had the drive swapped out, and then added the new drive to the arrays. Two of the arrays worked perfectly. The third added the drive back as a spare,…
T.J. Crowder
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How to boot after RAID failure (software RAID)?

Previously I had a software raid set up using (mdadm) of drives sda and sdb. sdb failed and the only way to reboot the system was by unplugging the second hard drive. Now I've added fresh sdb and sdc to my RAID setup. sda is the oldest (so most…
jaynp
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Linux RAID mdadm: what does 'Events' mean?

When I type mdadm --detail /dev/md0 I get a lots of useful information most of which I understand. However I also get a line that reads: Events : 0.710 Where the number varies. Naively, I thought an event either happened or it didn't. How can I…
Jaydee
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Daemon to verify Linux md raid

Is there a way to periodically verify that a linux software raid is valid and has no errors? Like a daemon that would scan all blocks and verify them.
Jackalheart
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mdadm: Disk configuration by UUID

I want to create a soft RAID-5 and use UUIDs im the mdadm config file. So I have four disks with 1 partition each that spans the whole disk. But since the partitons don'5 have a filesystem, blkid does not give a UUID. Is there a way to do that?
Daniel
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Removing a device in "removed" state from Linux software RAID array

My workstation has two disks(/dev/sd[ab]), both with similar partitioning. /dev/sdb failed, and cat /proc/mdstat stopped showing the second sdb partition. I ran mdadm --fail and mdadm --remove for all partitions from the failed disk on the arrays…
Sahas
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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 about 64% with an error, found out that sdb is…
phil
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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.
Sabya
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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 /dev/sdc2. Faithfully yours, etc. P.S. The…
Q789Bart
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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…
hraphrap
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EC2 disk goes to 100% util, but fine after reboot

We've been running some production services on Amazon EC2 for a while, using mainly t1.large and t1.xlarge instances (non-EBS). Every so often one of the attached (ephemeral disks) will get into a state of 100% util (as reported by iostat…
yegg
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Can you disable automatic mdadm startup?

I am creating a RAID 10 array over four iSCSI targets. I want to control everything manually though so I can run it through heartbeat. I've unlinked the open-iscsi and mdadm scripts from /etc/rc#.d/ but the raid array is still recreated on boot…
J.R.
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reshaping raid and growing raid

This is a two part question. 1) Can you reshape raid 5 to 6 with mdadm on linux (fairly sure you can, but cant get mdadm to accept it) 2) Can you do 1) while also growing the array in one go ?
Sirex
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Degraded RAID-5 array with lvm2 lost superblock and partition table

I have a RAID-5 array of 4x1TB hard disks with one lvm2 partition on Ubuntu Linux 10.04 LTS. One of the disks has failed. I have re-assembled the array without this failed disk but now mdadm --examine claims the array has no superblock and fdisk…
bountiful
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