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Questions tagged [mdadm]

A linux utility used to manage software RAID devices.

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RAID1 - mdadm mirror - not performing parallel reads as expected?

We have a three-way RAID 1 mirror which is powered by mdadm. I think I read that mdadm is supposed to take multiple simultaneous read requests and distribute them across different drives in the mirror (parallelize the reads) to improve read…
sa289
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Can mdadm convert a RAID5 to a RAID1?

I have a RAID5 consisting of 3 disks, one of which is broken. I was wondering if it is possible to convert those two disks to a RAID1 without data loss and without having to back-up the data elsewhere.
rausch
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Restore lost RAID1 volume on Synology with mdam

Several days ago I found my DS412+ in fatal state. Volume1 crashed, system volume too. Moreover, Volume2 disappeared from the system! It looks like Volume1 had no free space and cannot transfer data from a couple of bad blocks to a new place and…
Andre
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How to rebuild Raid arrays after booting to a live cd?

Problem: Botched kernel upgrade left me with an unbootable system (don't ask me how it also made my backup kernel unbootable) where boot and root are on mdadm raid 1 arrays (with metadata 1.0/1.2 respectively). Booting by live CD doesn't detect my…
Emma
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ThinkServer RD440 raid mess

Does anybody have experience dealing with raid config on these new Thinkpad servers? My problem is the following: In order to be able boot this server I must put the drives to RAID1 to create an SCM device. I did this with 2x1TB drives (then due to…
zino
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mdadm: Convert RAID10 to RAID1

The machine in question is equipped with 4x ssd, and running Debian wheezy 7.8, linux kernel 3.2.0-4, mdadm v3.2.5. Currently I'm using a RAID10 consisting of all these ssd. I've to increase the storage capacity, ssd are to expensive for this, and…
gxx
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Mdadm won't create an array larger than 10TB

I have a server with six 4TB drives running Ubuntu 14.04 LTS. One of the drives is used for the system/OS I wanted to use the other 5 drives to get as close to 20TB of storage as possible It's a short term data analysis project, so RAID 0 is fine I…
Rob
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Reading /proc/mdstat

I just built my first raid5 yesterday (with 4 hds) and was reading about monitoring with /proc/mdstat. My understanding is an ideal dispaly with 4 drives should be [UUUU] however mine reads [UUU_]. See below: Personalities : [linear] [multipath]…
Justin
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Redundancy: LVM+mdadm or LVM internal RAID

The task is to create LVM storage for virtual machine images. So LVM will be used in any case. There are two ways LVM providing redundancy: block mirroring lvcreate -m 1 --mirrorlog mirrored -n logical_volume -L 50G vg0 internal RAID…
eugene-bright
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2 disk RAID5 Linux software array

(I've posted this on Serverfault as I suspect it a bit to technical for Superuser. If I'm wrong please move it where appropriate) I am remotely looking at a device which identifies as ReadyNAS ProUltra2 V1.4. It appears this device has 2 disks in…
davidgo
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Linux; Set RAID5 chunk size to 4kB to match FS block size and physical disk sector size

There are many discussions and websites that explain the process of setting up a Linux software RAID with mdadm with the chunk size of a new RAID as 128kBs or 512Kbs. Serverfault is no exception. I am now building a new media NAS and I see no good…
jwbensley
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mdadm constant disk i/o

I have an mdadm array which has constant disk i/o. I know it's the array bc my server shows which specific drives have activity. According to iotop there's a constant disk write of 3-6 Mbps, however, there are no corresponding processes in the…
austin1howard
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MDADM RAID5 Size

I currently have 9x1TB disks in RAID5, which to me is 8TB worth of storage. However, I am not getting that at all. This was after moving from RAID6 to RAID5 and performing the necessary commands to resize the filesystem. mdadm --detail…
Steven Lu
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RAID-5 array being split on reboot (ubuntu)

I've set up a RAID-5 array on Ubuntu 13.04 (kernel 3.8.0-27-generic) using mdadm - v3.2.5 - 18th May 2012. It appears to work fine and be in high spirits: $ cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]…
fromClouds
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MDADM Rebuilding

I'm currently rebuilding a RAID6 MDADM array from 5 devices to 9. cat /proc/mdstat: Personalities : [raid6] [raid5] [raid4] md0 : active raid6 sde1[0] sdg1[9](F) sdh1[8](F) sdi1[6](F) sdj1[7](F) sdd1[4] sdc1[3] sdb1[5] sdf1[1] 2926751232…
Steven Lu
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