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Questions tagged [mdadm]

A linux utility used to manage software RAID devices.

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mdadm - stuck reshape operation

I have a 3 disk RAID 5 array that I tried to add a 4th disk to. mdadm --add /dev/md6 /dev/sdb1 mdadm --grow --raid-devices=4 /dev/md6 This operation started successfully and proceeded until it hit 51.1% cat /proc/mdstat Personalities : [linear]…
Cephas
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Linux raid10 on 2 disks

Linux mdadm has some quirks, one of them is building raid10 with only two disks. There are some reports that it's way faster (twice, both in read and write) as…
neutrinus
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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 that was connected, again, unrelated:…
Milos Ivanovic
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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 Partition Table: gpt Number Start End …
HTF
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RAID rebuilding seems to have stopped

My server was running a RAID 1 array with two disks. One of those disk failed today and was replaced. I've copied the GPT partition to the new hard disk (sda) with: sgdisk -R /dev/sda /dev/sdb and changed the UDID with sgdisk -G /dev/sda I've then…
Thomas Wang
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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 for…
ctrlbrk
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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 others, but I am paying the price. I must salvage…
ctrlbrk
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MD RAID sector repair

This article states that RAID controllers are smart about unrecoverable read errors, and try to rewrite such sectors with the redundancy of the component drives. If the sector is bad, the disk's firmware will reallocate the sector…
Halfgaar
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Linux software raid fails to include one device for one RAID1 array

One of my four Linux software raid arrays drops one of its two devices when I reboot my system. The other three arrays work fine. I am running RAID1 on kernel version 2.6.32-5-amd64. Every time I reboot, /dev/md2 comes up with only one device. I can…
user1389890
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How to get notified of mdadm RAID problems?

I am running Ubuntu 12.04 LTS. Yesterday I found a message in my mailbox saying that my server was shut down. I proceeded to reboot the system, but it didn't come up after many minutes, and I didn't have a hardware KVM system to see what the kernel…
Hongli Lai
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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 root partition is taking 1TB and the home partition…
Raul G
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mdadm - raid device name changed on reboot

I'm not sure why, but after I restarted my ec2 instance, /dev/md0 didn't start as it normally would. after I saw what's available in /dev/md*, instead of seeing /dev/md0, there is a device there named /dev/md127. I updated fstab to reflect the new…
imaginative
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How do you set up RAID1 with both disks bootable on Debian/Ubuntu?

In Debian 6, new installation, what is the recommended way of setting up a software RAID1 array so that the system is bootable from both disks? I have heard that people that don't know what they are doing may set it up in such a way that the system…
W3Coder
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How to create a software raid5 array without a spare

I am trying to create a software raid5 array using mdadm: $ linux # mdadm --create --verbose /dev/md0 --level=5 --raid-devices=4 --spare-devices=0 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 mdadm: layout defaults to left-symmetric mdadm: chunk size…
Yannick Motton
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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 reported by the system: cat…
haimg
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