A linux utility used to manage software RAID devices.
Questions tagged [mdadm]
844 questions
5
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Speed very slow when Resync Hard disk with mdadm
Problem: When I add sda3 to /dev/md3 the speed of two disk decrease... a lot, it decrease to ~100k
Question about why it decrease the speed.
It will be because the server is running in normal mode, and all services are in operation.... ? like…

DarckBlezzer
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Linux RAID 1: How to make a secondary HD boot?
I have the following RAID 1 on a Centos 6.5 server:
# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdb1[3]
974713720 blocks super 1.0 [2/1] [_U]
bitmap: 7/8 pages [28KB], 65536KB chunk
md1 : active raid1 sdb2[3] sda2[2]
…

Fernando
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mdadm Boot Error, incrementally starting raid array Ubuntu SErver 14.04
i build a small Server with Ubuntu 14.04 for Samba,
I has one SSD Drive (the ubuntu installation is on it)
and 2 3TB SATA Disk,
the sata disk are combined to a Raid 1 with mdadm.
Now sometimes (no everytime, i think it's maybe related to a dirty…

user279118
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Linux mdadm --grow RAID6: Something wrong - reshape aborted
I have a RAID60 that I want to expand.
The current is: 2 axles each having 9 disks + 2 spares.
The future is: 4 axles each having 10 disks + 1 spare.
So I need to do some --grow to reshape the drives.
I thought this would be enough:
mdadm -v --grow…

Ole Tange
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1 answer
mdadm: Growing a RAID0 Array Weirdness
I have created 3 RAID0 arrays using mdadm on 3 Rackspace CloudServers using Rackspace's CloudBlockStorage as their devices. Each array has their own set of CBS volumes. RS-CBS has an upper limit of 1TB for their drives and I needed larger storage.…

Ken S.
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Is my hard drive about to die?
I have two hard drives set up as a RAID 1 array on my server (Linux, software RAID using mdadm) and one of them just got me this "present" in syslog:
Nov 23 02:05:29 h2 kernel: [7305215.338153] ata1.00: exception Emask 0x0 SAct 0x1 SErr 0x0 action…

Hristo Deshev
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Linux software RAID6: rebuild slow
I am trying to find the bottleneck in the rebuilding of a software raid6.
## Pause rebuilding when measuring raw I/O performance
# echo 1 > /proc/sys/dev/raid/speed_limit_min
# echo 1 > /proc/sys/dev/raid/speed_limit_max
## Drop caches so that does…

Ole Tange
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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 is backed-up somewhat infrequently. I think I'm…

Álex
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How do I get mdadm to auto assemble my raid array?
After upgrading to Ubuntu 9.04, my raid 5 array is no longer being assembled correctly. Right now, from boot, it will start a raid array using ata-MAXTOR_STM3500630AS_9QG03T0L-part1, at /dev/md0, but that is fail because it isn't my whole Raid 5…

Montana Harkin
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3 answers
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 /dev/md0 via:
mkfs.ext4 -v -b 4096 -t huge -E…

senojsitruc
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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 drives back into a working array.
because md0 was…

pironic
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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 (e.g. /dev/disk/by-path and by-id).
I already changed…

UloPe
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2 answers
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 rsec/s wsec/s avgrq-sz avgqu-sz await svctm …

Mitar
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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 operation without removing and adding back failed…

hraphrap
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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
Personalities : [linear] [multipath] [raid0] [raid1]…

chrishiestand
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