A linux utility used to manage software RAID devices.

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Cannot install grub, segmentation fault, unable to identify filesystem, superfluous RAID member, found two disks with same index — Debian 7

A server was recently transported from location A to B, a long journey that took six months. Things have gone wrong due to nothing being labeled prior to shipment. Yes, I know --- it was done by ...
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Ubuntu RAID1: How to boot after (physically) removing /dev/sda? (mdadm, Grub2)

Several months ago I installed Ubuntu 14.04.2 Server (x64) with RAID 1 using the following instructions: https://help.ubuntu.com/lts/serverguide/advanced-installation.html I followed the ...
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2answers
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Where do md array definitions come from?

I created a md array in an ARM computer with two USB/SATA disks in RAID 1. Then I moved both disks to my Ubuntu desktop and installed mdadm. Installation detected the RAID and added the definition to ...
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3k views

Grub rescue, will not boot from mdadm RAID, no such disk or device — mduuid wrong?

I am running a 14 disk RAID 6 on mdadm behind 2 LSI SAS2008's in JBOD mode (no HW raid) on Debian 7 in BIOS legacy mode. Grub2 is dropping to a rescue shell complaining that "no such device" exists ...
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Can't see other VHDs after detaching another. Azure Ubuntu VM

We have encountered high Disk IO on our Ubuntu 14.04 VM's running mongoDB. On Windows Azure. To solve this issue we have changed the VM size from A2 to A3 (to add the additional data discs) and ...
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1answer
29 views

Linkstation WXL: RAID disappeared, /dev/md2 is inactive - how to troubleshoot

today I had problems accessing the SMB-share on my Linkstation. My NAS has two hard drive disks, configured as raid0. this raid was mounted to /mnt/array1/intern - the folder that i am missing. My ...
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1answer
1k views

Recover mdadm RAID 10 array: listing all as spares

I'm a bad person and haven't backed up my RAID elsewhere. I now have a RAID10 array that won't assemble, and I'm hopeful I can save it. Here's the details: I have five hard drives set up as RAID10 ...
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21 views

MD RAID Array Often Starts Without All Drives

I find that, when I start/restart my system, my MD array often doesn't start with all of the drives even though the device-names haven't changed at all. I'll have to stop the array and reassemble it, ...
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1k views

Resize openSUSE 12.3 GPT ext4 partitions in a RAID1 disk array

I have a software raid configured (/dev/md2) which has assigned the partitions sda3 and sdb3 from two 3TB disks (sda and sdb). The partition types are GPT not LVM and file system is ext4. Now, the ...
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flashcache with mdadm and LVM

I am having trouble setting up flashcache on a system with LVM and mdadm, I suspect I am either just missing an obvious step or getting some mapping wrong and hoped someone could point me in the right ...
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23 views

Software RAID 1 does not extend on two new additional drives

I added two new devices two my software RAID 1 system. They are recognized by mdadm but I can't use the addition space. Here is how I proceed: I added the two new disk to my PC and created on each ...
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31 views

Recover overwritten RAID5 array (XOR)

as I've mentioned in a recent question (RAID5 rescue with LVM2 running on it) I'm rebuilding an RAID5 array. Now, I think that the initial wrong mdadm --create ... command has started the ...
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1k 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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112 views

CoreOS on software RAID with EXT4 filesystem

I'm currently thinking about installing the CoreOS on a bare-metal server with two disks I want to put in a software RAID1. The latest CoreOS is now using EXT4 as their default filesystem and I'm ...
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38 views

Resetting root password on Slackware (software RAID)

I'm trying to reset password to root account on Slackware server (with Intel Atom on Intel motherboard and two HDDs). There is software RAID set up (devices mounted during boot: md0 - /, md1 - /usr, ...
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18 views

mdadm does not let me set --size manually, but grows to the same size later

I'm trying to make raid1 out of 2 disks the size of which differs a lot (ec2 provides iops based on disk size, so I want to have more iops, but don't care about losing some free space). However when ...
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39 views

Remove a drive from a 2-drive RAID 5 array using version 1.2 metadata?

My situation is nearly identical to "How to remove a drive from a non-standard 2-drive RAID 5 array?", except my 2 TB RAID5 is using mdadm super block version 1.2. According to the best answer, ...
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31 views

Shrinking LVM Volumes

We have a Synology RS3614rpxs NAS head containing (9) 3TB hard drives in a RAID 6 + 1 hot spare. The storage became exhausted and we added an expansion chassis where 5TB hard drivers were installed ...
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mdadm 3-way RAID 1 - good solution for guaranteed 2-drive failure tolerance?

Is a 3-way RAID1 using mdadm a good solution to be able to sustain any two drives failing without the RAID failing? I know this costs extra in the sense of only being able to use 1/3 of the disk ...
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186 views

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 ...
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52 views

Data recovery seems impossible after kernel upgrade. MDADM (Raid1) LVM2

I opened a question about rebuilding a bad partition My Problem that din't take me anywhere. Bad news is the company trying to rescue the data says it's finding huge inconsistencies they can see some ...
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1answer
150 views

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 ...
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Software Raid: Array inconsistent state

I'm running software raid 1 with md on debian distro. One of the disks has failed, but not all of the raid arrays were at that time in a "fail" state. In order to bring them also in a fail state (in ...
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41 views

Rescue mdadm RAID 6 array after three disk events

mdadm 3.2.5, 14 disk RAID 6 Had a drive failure Friday. Two more today in rapid succession. All drives seem fully operational. This is roughly 40TB array, I could use your help please to rescue ...
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103 views

How can I force soft raid to read only from one disk?

I have quite a large IO wait showing in top. I suspect this is fault of SDA drive (on of 2 disks in RAID array), which was replaced about week ago. There are no errors visible, smart showing nothing, ...
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662 views

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 > ...
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40 views

mdadm array keeps losing disks on separate SATA controller

My Ubuntu Linux server has an mdadm array (RAID 5) with four 2TB SATA disks that keeps "loosing" two disks from time to time. Rebooting and re-assembling the arrays has worked out fine up until now. ...
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565 views

Linux RAID1 Software - grub resync after fail

I've a linux server with 2 IDE HD & Raid (hda - hdb) I've changed the "BAD" hdb with a new: mdadm --fail /dev/md2 /dev/hdb3 mdadm --fail /dev/md0 /dev/hdb2 mdadm --fail /dev/md1 /dev/hdb1 ...
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128 views

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 ...
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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 ...
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249 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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42 views

Grow individual drive size in RAID5 array

My array is built of 3 hard drive of 2TB, I have 2 more free space and I would love to start to grow my array with 4TB hard drives, if I start to put 2 4TB hard drives and eventualy replace the 2TB ...
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In a software RAID1, why does tune2fs -c 0 /dev/sda1 not throw an error but change is not seen in tune2fs -l /dev/sda1?

The Title pretty much says it all. Turn off mount count fsck seems to succeed: tune2fs -c 0 /dev/sda1 tune2fs -c 1 /dev/md0 But listing out via tune2fs -l /dev/sda1 shows mount count is set back ...
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How to have automatic file system checks for Linux Software Raid?

In a Linux Software raid, what is the best practice for periodically having the filesystems checked? With single drive or hardware raid, tune2fs -c 5 -i 1w /dev/sda1 means check the filesystem every ...
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66 views

Files missing after RAID1 restore

I have encountered unpleasant situation. Given mdadm RAID1 of 2 HDD on server. Yesterday one of HDDs completely dies, other shows bad SMART status but was in accessible state. Mdadm showed "clean, ...
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mdadm: activating spare and removing 'removed' disks

I added 1 disk to my raid array, started reshaping, and then remembered that I forgot to partition the drive. So I partitioned and readded the disk. I'd like to get rid of that 'removed' and activate ...
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219 views

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 ...
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1answer
91 views

Ubuntu server becomes unresponsive on hard disk issues despite raid setup

I am running a server on Ubuntu 10.04.4 LTS (Linux xxxx 2.6.32-67-server #134-Ubuntu SMP Wed Sep 24 18:55:00 UTC 2014 x86_64 GNU/Linux) with two hard discs in a software raid 1. I repeatedly had the ...
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38 views

mdadm isn't rebuilding the array

I recently replaced a drive (/dev/sdb). All arrays have been rebuilt correctly except for one of them (/dev/md2). There is no problem with the new drive. Partitions are OK. mdadm says it's "spare ...
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1answer
56 views

mdadm: drive replacement shows up as spare and refuses to sync

Prelude I had the following devices in my /dev/md0 RAID 6: /dev/sd[abcdef] The following drives were also present, unrelated to the RAID: /dev/sd[gh] The following drives were part of a card reader ...
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299 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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158 views

How to setup Debian Jessie to boot from broken RAID1

I want to setup Debian Jessie in EFI-mode with a LVM on an LUKS on a RAID1. I tried it with the Installer but when i remove one of the hard drives the whole system isn't booting any more. What I ...
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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 ...
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mdadm raid5 recover double disk failure - with a twist (drive order)

Let me acknowledge first off that I have made mistakes, and that I have a backup for most but not all of the data on this RAID. I still have hope of recovering the rest of the data. I don't have the ...
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Disaster recovery. MDADM/LVM2 Some advance but stuck on final mount

We made a stupid upgrade on a running server using wrong repositories and the system became totally unbootable. The system, a SLES 11 we used a openSuse repository to upgrade, and everything went ...
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1answer
31 views

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 ...
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865 views

mdadm & raid6: does “re-create(with different chunk size) + resync” destroy orig. data?

I would like to rescue data on my software raid-6 array. I did some stupid actions (described bellow) with this original array. Main Question: I need to know if original data stored on raid-6 array ...
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354 views

CentOS 7: GPT and software RAID 1 without 'biosboot' partition

I have a CentOS 6 server with software RAID1 (2x3TB): - sda # parted /dev/sda unit s print Model: ATA TOSHIBA DT01ACA3 (scsi) Disk /dev/sda: 5860533168s Sector size (logical/physical): 512B/4096B ...
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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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2k views

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 ...