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Questions tagged [mdadm]

A linux utility used to manage software RAID devices.

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Odd mdadm output: --examine shows array state failed, --detail shows everything clean

The setup: 8 disks in a mdadm-managed RAID5 array (/dev/md0, made from /dev/sdc through /dev/sdj). One disk (/dev/sdh) is showing SMART errors (increasing pending sector count) so I'm looking to replace it. Additionally, the machine boots from a…
Runc
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LVM-on-RAID vs RAID10 vs RAID6

In the spirit of the question LVM mirroring VS RAID1 I thought I'd push a bit further. Suppose I have 4 identical hard drives (e.g. 1TB) that I want in a RAID setup for a backup/media server. LVM over the top seems to be current best practice for…
Andrew
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Degraded partition in RAID5 system

I've got a server running Debian Squeeze and a 3x 500 GB-drive RAID5 system which I haven't set up myself. When booting, the status of one partition in the RAID-array seems to be bad. md: bind md: bind md: bind md: kicking…
nip3o
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mdadm raid6 recovery reads more from one drive?

I just replaced a fault drive in my raid6-array (consisting of 8 drives) during the recovery I did notice something strange in iostat. All drives are getting the same speeds (as expected) except for one drive (sdi) which is constantly reading faster…
Peter
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Putting a spare Raid device back to active state

I have a problem with my Raid setup. I have 3 disks in my Raid: md2 : active raid5 sdc3[3](S) sdb3[4](S) sda3[0] 2925532672 blocks level 5, 64k chunk, algorithm 2 [3/1] [U__] md1 : active raid1 sdc2[2] sdb2[1] sda2[0] 264960 blocks…
disco crazy
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Why does MDADM Raid 5 require a spare

From the mdadm man page: "When creating a RAID5 array, mdadm will automatically create a degraded array with an extra spare drive. This is because building the spare into a degraded array is in general faster than resyncing the parity on a…
Gary
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Mdadm - Change RAID 10 chunk size and switch to "far" layout

I'm running an Ubuntu Linux NAS server with 4 2TB drives in software RAID 10. I created the array during installation (with Ubuntu Server disc), but the layout is near and the chunk size is 64. I want to change the chunk size to 256 and the layout…
Andrew Ensley
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How to diagnose intermittently slow raid data transfer rate?

I have an encrypted RAID6 set up on Centos 5.5. When I transfer a large 10gb file from the raid to my computer it will pause at around 4-5gb and again at 9gb. The data transfer drops from 25mb/sec to < 1mb/sec for about 30-60 seconds. Streaming HD…
zio
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How to remove previous RAID configuration in CentOS for re-install

I have a server that was previously setup with Software RAID1 under CentOS 5.5 (/dev/sda and sdb). I added two additional drives to the server and was attempting re-install CentOS. The CentOS installer sees the 2 new drives fine (sdc and sdd),…
John P
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Linux Mdadm + LVM recovery

I recently reinstalled my Ubuntu server with 10.04, and am having trouble reactivating the LVM partition which houses all my non-critical data. /dev/sda, /dev/sdb, /dev/sdc, and /dev/sdd are all assembled into a Raid-5 array /dev/md0, upon which…
Darth Android
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Is it possible to change the Raid5 chunk size of an existing device?

I have an existing raid5 device which I created using mdadm on Linux. When I created the device I set the chunk size to 64 but I would like to test the performance of various sizes but I don't want to have to rebuild my entire system to do so. If…
AlexCombas
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Is mdadm Raid-1 Over A Network File Share Possible?

I am using 64bit CentOS 5.5 I know it's possible to set up software RAID1 using mdadm using a physical hard disk and a RAM disk. Is it possible to set up software RAID1 with mdadm using a NFS mount and a RAM disk instead? Or another way to put the…
Travis
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Getting Grub2 to recognize a Raid 10 boot/root

I've been trying to get my raid to boot from grub2 for about 2 days now and I don't seem to be getting closer. The problem appears to be that it doesn't recognize my raid at all. It doesn't see (md0) etc. I'm not sure Why or how to change this. I'm…
xenoterracide
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Is there any way to build a linux software raid system without all drives?

I'm building a raid1 (ok it will probably be a raid10,f2 but the difference with 2 drives... isn't much) system with 2 1TB drives. However, 1 of the drives I've ordered is bad so I'm RMA-ing it. I'm wondering if I could partition and install to the…
xenoterracide
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mdadm software RAID doesn't load at boot

I'm using mdadm to create a raid1 mirror across two disks. I can create my /dev/md5 array perfectly using the tools, but it does not automatically reload my /dev/md5 when I restart, I need to manually recreate the array. Am I missing something…
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