A linux utility used to manage software RAID devices.

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513 views

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 ...
3
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0answers
897 views

Very poor disk performance on KVM node - mdadm raid10

For a long period of time, i'm experiencing performance issues on CentOS servers that are used for KVM virtualization. I'm running software RAID-10 with 4 disks (Seagate ST2000DM001, 2TB, 7200rpm ...
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0answers
107 views

RAID1 disks “forked”, now duplicate

I have got a server hosted by OVH, which is configured to have a soft RAID1 array, /dev/md0, that holds a LVM PV. There is another /dev/md1 array, which was supposed to be the /boot, but which is ...
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2k views

How to recover an mdadm array on Synology NAS with drive in “E” state?

Synology has a customized version the md driver and mdadm toolsets that adds a 'DriveError' flag to the rdev->flags structure in the kernel. Net effect - if you are unfortunate enough to get a array ...
2
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0answers
346 views

mdadm error: found two disks with the number 0

Im running a server deep in the forest , and after a hard disco failure i got this error. error: found two disks with the number 0. It a server with 2, 1 TB disc in raid 1 with mdadm 0.9 SDA failed ...
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289 views

Restore LVM if VG is not consistent (XenServer 5.6.1)

i have a VG that uses the PVs /dev/md1 and /dev/md2. Now one hdd failed in /dev/md1: [root@xenserver1 ~]# cat /proc/mdstat Personalities : [raid1] md1 : active raid1 sda3[0] 382320128 blocks ...
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896 views

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 ...
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195 views

raid 5 mdadm drive dropped whilst growing

I have a 4x 2tb raid 5 mdadm array which I had begun to grow onto a 5th disk. ~# mdadm --add /dev/md1 /dev/sdb ~# mdadm --grow /dev/md1 --raid-devices=5 midway through the grow I recieved this in ...
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123 views

Debian squeeze server hangs when accessing md raid 5 over network

My debian squeeze server ha begin to hang/freeze when I try to access my md raid 5 over network (via samba or afp/netatalk). This behavior started when I installed netatalk, libgcrypt11 from wheezy. ...
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1k 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 ...
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330 views

MD Raid can't be assembled

I was running a Raid5 with 3 disks at on my homeserver. But had some problems with the back-plane for the disks. The disks weren't detected reliable. So I replaced the back plane and the disks are now ...
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437 views

How do I create a RAID10 array using EBS on Amazon?

Basing this question on information I got in Why does df shows only half the size of a RAID10 array?, how should I create a RAID10 array using EBS volumes on Amazon, in a way that will not be ...
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0answers
151 views

mdadm LBA mapping

I am trying to write a script similar to mdtrim (https://github.com/Cyberax/mdtrim) for a raid 0 software raid through mdadm. The mdtrim is for raid 1 only at the moment, and it works by writing a ...
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72 views

To write in mdadm.conf in initramfs prompt doesn"t not save changes after reboot

I made a mistake with my mdadm.conf with my debian backup server. I used this command : mdadm --detail --scan --verbose >> /etc/mdadm/mdadm.conf to add a raid5 (it works great). By using ...
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749 views

Ubuntu 14.04 mdadm issues on boot

I have a 14.04 Ubuntu machine which has: 2 x SSD in RAID 1 (md0) 3 x Sata HDD in RAID 5 (md1) The machine is set to boot from the md0 device. This machine has been running fine for a month or so, ...
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102 views

Upgrade Raid 1 to Raid 0+1 and bootloader issue

I am trying to convert my current RAID 1 to RAID0+1 and facing issue in installing bootloader - please have a look what i am doing. My current configuration is RAID1(2*10GB): [root@localhost ~]# ...
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95 views

shrink live mdadm partition with LVM

My goal is to shrink an mdadm RAID 1 partition while the system is running. I have to disks sda and sdb, which build my two RAID partitions md0 and md1. On md1 I use LVM, md0 is the /boot partition. I ...
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284 views

calculating optimal chunk size for Linux software-RAID

Am I correct that optimal chunk size is average file read/written to disk divided by number of block devices in RAID array storing the data? For example if the average file size is 1024KiB and I have ...
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465 views

grub on debian wheezy doesn't recognise mdraid

We're having a really strange problem when trying to boot from an mdraid on Debian Wheezy. All references online that I can find tell me that grub 1.99 (which is part of Debian Wheezy) should have no ...
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120 views

expanded 8 drive RAID 6 fails to assemble in new server, 5 original devices show no md superblock

I am in desperate need of you help. Neil Brown does fantastic work, and I have relied on mdadm for years to run very stable server systems, never had major problems I could not solve. This time its ...
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34 views

mdadm confused on minor number

Recently replaced a faulty disk in my Raid 6 group. All went as expected, no problem. After getting everything rebuilt using a new /dev/sdi1 as a replacement for the failing /dev/sde1 I decided to ...
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300 views

syncing mdadm event count

I had a disk die in my level 5 RAID and before I could replace it, my RAID crapped out while I was copying some data onto it. Reading the RAID kernel wiki on RAID recovery I've tried forcing an ...
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188 views

How to disable MD RAID or prevent degraded arrays from starting. (Centos 6.4)

I am trying to disable software RAID at boot time. My ultimate goal is to prevent the system from starting raid arrays that are in a degraded state. rd_NO_MD is present on the kernel command line by ...
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163 views

Resize a RAID 5 Partition

I'm moving my VG to a RAID, i have 3 disk 600GB, the VG is in the partition /dev/sdc2 /dev/sdc1 1G type linux <-- Boot partition /dev/sdc2 599G type Linux LVM One disk have the VG and with the ...
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84 views

Expanding raid5 software raid

I have recently bought 4 2TB drives to expand my existing 4*2TB raid5 setup, using mdadm software raid in debian. As a initial step, I have created a raid5 on the four new drives and created an ...
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85 views

Fresh debian squeeze software raid install wont boot

I am following these instructions: http://www.iprobot.net/linux-tutorial/how-to-setup-software-raid-in-debian-ubuntu/ (I used debian-live-6.0.6-amd64-gnome-desktop.iso and DD'd that onto a usb key, ...
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151 views

mdadm drive UUIDs chanaged, can they be changed back?

So I ran into this trouble and I believe I lost all my data..However I found an old mdadm --examine --scan file I made a month ago and an old mdadm.conf....Is it possible to use these two items to fix ...
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197 views

Raid1 disk degraded after reboot

I'm testing a Rackspace cloud server and have two Cloud Block Storage volumes set up in a Raid1 configuration. There are no system files on these volumes, they're purely for storage. Everything ...
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238 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 ...
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173 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 ...
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880 views

mdadm raid1, [1/2] disks failed, safe to reboot?

I am seeing the following under /proc/mdstat Personalities : [raid1] md1 : active raid1 sda2[0](F) sdb2[1] 976554876 blocks super 1.1 [2/1] [_U] bitmap: 4/8 pages [16KB], 65536KB chunk md0 : active ...
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283 views

After upgrade to SLES11 SP1 - LVM on top of software RAID5 not working anymore

On a system where I have been running OpenSuSE11.1 for some time I performed a fresh installation of SLES11 SP1. The system used a software RAID5 system on top of which an LVM was setup with a single ...
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252 views

Reassemble RAID 10 array without losing data

I have a RAID 10 array created from 4 iSCSI devices. This morning I temporarily lost connectivity to 2 of those drives. And it was long enough for mdadm to take them out of the array. Unfortunately ...
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25 views

mdadm/grub2/lvm boot failure if all drives are physically connected

Weird problem here. I've got a Debian 7 server (quad core, 32GB RAM) that runs a whole bunch of VMs. The main boot drive is a RAID 1, with an LVM volume group called System, which contains a bunch of ...
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27 views

Increase space on RAID 10

I have a RAID10 with 7 working devices ,4 actives and 3 spares .I want to increase the RAID's space from 4 devices to 6 . i use this : sudo mdadm --grow --raid-devices=6 /dev/md0 but it gives me ...
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22 views

Order of execution: First file system, then array vs. first array, then file system

Suppose I have two HDDs, same manufacturer, same model, same attributes (volume, speed, cache, ...). Both are equally partitioned. I want to have a level one array of two disks with one ext4 ...
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47 views

mdadm: can't remove broken drive from raid1

I have a ubuntu server Ubuntu 12.04.5 LTS (GNU/Linux 3.2.0-34-generic x86_64) that uses a software raid with 2 physical drives. Apparently, one drive is unresponsive, and I try to remove it from ...
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31 views

mdadm - unable to reconstruct the raid1

When restarting my server, it (sometimes) fails to reconstruct my RAID-1 array (2 disks). My server, a 10-year-old computer, often changes sda into sdb or sdc which seems to annoy mdadm. When it ...
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41 views

Resizing a software RAID remotely, no LVM, / partition

I have a server that has a software RAID without LVM. That is only mdadm. There are the partitions /dev/sda2 and /dev/sdb2 which form /dev/md2. There is also a lot of space after both /dev/sda2 and ...
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163 views

mdadm RAID0 array recovery

I have a Linux file server with two 12-disk MD1000 disk arrays attached to a RAID controller. Unfortunately, a power blip has caused a loss of configuration data on the RAID controller and it is now ...
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51 views

mdadm reattached a failed drive all by itself

I have 2 drives setup in mdadm mirroring (3 partitions on each drive). Last week the second drive (sdb) dropped out of the array because of some I/O errors I am still investigating. After a server ...
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0answers
134 views

mdadm: All RAID disks look good, but can't access devices

Now, granted, issues with RAID rarely come up (at least with the one that I have to deal with in my life), so I'm not the most experienced person in the world. However, I'm not seeing any issues with ...
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52 views

Did mdadm --create destroy my data?

I think I messed up pretty bad. On my old system, I had 2 identical drive that were assembled with mdadm as a MD RAID 10 with a "far" layout. When building my new system and migrating the two disks, ...
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454 views

Optimizing disk performance on KVM VM configuration

I have a KVM host server running Ubuntu 12.04 LTS, bare bones installation with only KVM installed. The server has an 8 Core Intel(R) Xeon(R) CPU E3-1230 V2 @ 3.30GHz CPU with 32GB of RAM and SATA ...
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0answers
132 views

Software RAID: file system becomes read-only, mdadm fails with SEGFAULT

I have software RAID1 on Ubuntu 10.10 (Linux ubuntu 2.6.35-32-generic-pae). It is dedicated server I control via SSH. Yesterday datacenter people changed one HDD which was crushed. I did not run ...
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101 views

confused by iostat reporting striped mdadm more tps than aggregate volumes

I've got an mdadm striped device (/dev/md0) from /dev/sdm{1..4}. Here is an output of iostat 30 and then mdadm --detail on the mdadm device # iostat 30 Linux 2.6.32-309-ec2 (ip-xx-xx-xx-xx) ...
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129 views

mdadm array fails to start at boot, bad superblock on component drive

At boot my mdadm raid5 array fails to start, saying that one of my disks (sdi) has a bad superblock. However, once I log in, I can start the array no problem with mdadm --assemble /dev/md0 ...
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21 views

Harddrive check going-on?

I have a server that has suddenly become unusable (responds very slowly to requests). It seems to be related to some on-going RAID check. Here is what I get when I run cat /proc/mdstat : ...
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81 views

Replace a slowly dying drive in Linux software raid5

I have the same problem as in Can I "atomically" swap a raid5 drive in Linux software raid? i.e. a Linux software raid with 3 RAID5 disks where one disk is showing smart errors but isn't ...
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101 views

why cant I set the correct partition size in fdisk

I am currently attempting to setup a raid array. At this point in time I am setting up partitions of the same size on each hard drive that I would like to use in the array, although when I used fdisk ...