A linux utility used to manage software RAID devices.

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Can't stop and reformat /dev/md0

I want to reformat /dev/md0, which is a RAID0 array consisting of 4 disks (sd[bcde]). However, when I tried to run the command mke2fs, I received the following error message: /dev/md0 is apparently ...
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46 views

Unexpected discrepancy between write and read performance using cryptsetup 1.4.3 and 1.6.6 on Debian Wheezy (7.9) and Debian Jessie (8.2)

I have been setting up a raid1 array and have set up an encrypted medium using cryptsetup with default options. The raid arrays are supposed to use 2 drives, but for the moment, I only have 1 drive in ...
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38 views

Recovering an RAID6 using ddrescue. mdadm: failed to add, invalid argument

I had 3 drives fail in a matter of a week on a RAID6. Luckily, one drive seemed to be mostly fine. I was able to run ddrescue and it copied all but one small area (couldn't read 14MB out of 3TB). ...
2
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1answer
48 views

Mdadm raid1 says the last drive attached has failed

I have a software raid1 array. Today I found one of the drives failed to sync, and I got this: $ cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb1[0] sda1[2](F) 153597312 ...
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62 views

Ubuntu 14.04 Software RAID 1 - md0 inactive

I have my root filesystem on /dev/sdc, and a software RAID 1 spanning /dev/sda and /dev/sdb (I think). I physically moved my computer and ran software updates today (either of these could be the ...
2
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1answer
68 views

Replaced SATA controller, software RAID (mdadm) stopped booting: grub rescue> no such disk

I have a relatively old server machine which has no SATA ports on the motherboard (Dell Precision Workstaion 650). Also have a cheap FakeRAID controller (VIA VT6421 Chipset) and two Seagate 3TB drives ...
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1answer
35 views

Copy centos 6 modify mdadm raid 1 and clone to new mdadm raid 1 ssd

I have: Centos 6.7 grub-install -v grub-install (GNU GRUB 0.97) lsblk two new SSD 128gb Live usb with Parted_Magic_2015.03.06 /boot/grub/device.map # this device map was generated by ...
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1answer
31 views

mdadm RAID 6 rebuild when remaining drive(s) have bad sectors

I'm setting up a system at work to store some critical data. I will be using 4 x 1TB drives to create RAID6 via mdadm. I did lots of reading and can't find a definite answer to my question: In a 4 ...
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1answer
34 views

dracut-pre-trigger rd.md=0 removing md raid activation boot fails

The system is Fedora 22, recently upgraded from Fedora 21. The remaining kernel from Fedora 21 boots. The two kernels installed after the upgrade fail to boot. The system is an Intel S-5000 PAL with ...
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1answer
39 views

mdadm: can I reconnect a USB disk as SATA without needing a rebuild?

In my server there's an mdadm RAID-1 array consisting of two SATA disks, named sdb and sdc. The sdb disk might fail soon (according to SMART data), and I want to replace it with a newly bought disk. ...
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24 views

mdadm RAID1 won't rebuild

A drive on one of my Hetzner servers failed yesterday. I've replaced it once before, but this time it just will not work. After I copy the GPT to the new disk, I add one of the partitions to the ...
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39 views

“personality does not support diskops!” when trying to add a drive to a mdadm raid array

I have a linux (3.19) server which uses software raid (mdadm v3.2.5) and there is a raid0 device (/dev/md2) set up, which currently has only /dev/sdb3. I want to add the unused disk /dev/sda3 to this ...
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1answer
65 views

Linux- Convert 2 disk raid1 to raid0

I have a linux server (3.19.0) which has raid setup with md (v3.2.5). / is a raid1 device with 2 disks. There was a mistake when installing this machine, instead we need those 2 disks to be in raid0 ...
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2answers
22 views

Can I convert a single-disk system to software RAID1 without double-copying?

I have read this question: Can I create a "soft" RAID1 array without nuking data? as well as many other tutorials that layout this general process: Create degraded RAID1 array on new drive ...
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1answer
34 views

Advice for creating CentOS mdadm software RAID6

EDIT: Solutions to my issue are below I want to create a well optimized RAID6 array with mdadm with an XFS partition on a CentOS system. It'll involve ten ST3000DM001 Seagate 3TB drives and I'll be ...
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0answers
18 views

mdadm raid1 back to single drive

I have a raid1 install of debian 7 with software mdadm on 2 disks. What I want here is to split this to 2 separate systems and be able to multiboot them. I guess while I have the system running ...
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2answers
60 views

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 RAID1: ...
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45 views

RAID10 with 24 drives on Linux

I have an Ubuntu server with attached 24x1TB drives, which I would like to use for storage. I would like to use RAID10 with ext4, but all examples I saw (such as ...
0
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1answer
238 views

NVMe drives write performance in software RAID 1

We have just received two brand new Supermicro servers 1028U-TN10RT+ with 10 NVMe slots, two of them with Intel DC P3600 800gb hard drives. We were eager to test the performance of the drives as the ...
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22 views

RAID5 needs drive to be added every reboot

I have a 3 disk RAID5 mdadm array total 4TB on an Ubuntu Server 14.04.3 LTS. Since a kernel panic caused by a device unrelated to the array and that has been already replaced, after every reboot the ...
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3answers
33 views

Different free disk space figures in df output after complete rsync -Sap transfer

I did "rsync -Sap --numeric-ids --delete-during /mnt/RAIDVault/ /mnt/RAIDVault-BACKUP/" intending to bring two storage units in sync (having identical content) but ended up with different amount of ...
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79 views

RAID 5 keeps failing after recovery

I have configured a raid 5 with 6x2TB devices with mdadm (I shrinked it from 9 devices to 6): /dev/md0: Version : 1.2 Creation Time : Mon Sep 23 17:54:25 2013 Raid Level : raid5 Array ...
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1answer
133 views

How do I troubleshoot my RAID array?

I just checked into my RAID array this morning and what I got is: $ cat /proc/mdstat Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10] md1 : active raid1 sdc7[0] ...
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1answer
30 views

md raid10: how to make sure that replicated data is stored in right place?

When creating classic mirrored raids, it's usual to locate copies of data on disks of different kinds. In this case you would use a mix of disks of different series and manufacturers. That reduces the ...
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1answer
268 views

Debian server has degraded mdadm array on every boot

I have a Debian server with MD raid (2 actives, one spare): Personalities : [raid1] md1 : active raid1 sdc2[0] sdb2[1] sda2[2](S) 1068224 blocks [2/2] [UU] md0 : active raid1 sdc1[2](S) ...
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82 views

Replace failed disk in RAID 1

two days ago one of my two drives in my software RAID 1 (that was setup using gnome-disks) configuration failed. I could not access the files in the meantime. After short research it seems that I have ...
2
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2answers
73 views

mdadm fault injection testing with bad blocks or other unrecoverable errors

I recently lost a drive in my RAID array (and got an email from the system warning me of this, which was awfully nice) and after some drive shuffling and swapping in a new drive I'm all safe and ...
1
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1answer
111 views

Linux Software RAID10: Mysterious renaming /dev/md0 to /dev/md127: Why?

During the last two nights we had mysterious events on a server running Ubuntu Linux 12.04 LTS with a Linux mdadm software RAID10: DeviceDisappeared /dev/md0 NewArray /dev/md127 Both messages ...
3
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1answer
284 views

recover highly degraded raid array

I have a Linux RAID6 array (mdadm) composed of 8 disks. 2 disks failed. I replaced them, now I have 2 new empty disks. I would like to rebuild the raid but when I start a raid rebuild, the rebuild ...
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53 views

How Do I resize a partition? [closed]

I have the following FIle system setup currently. I need as much room as i can get in ./home. root@Jm2:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/md1 20G 7.6G 11G 42% ...
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1answer
40 views

Recently installed RAID already degraded on partition

I set up setting up a new two disk RAID1 which appeared healthy in mdstat. In a few hours, here's what I later saw when I ran cat /proc/mdstat. Personalities : [raid1] md1 : active (auto-read-only) ...
0
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1answer
91 views

mdadm set the mode before a second device raid1?

i have a problem. server use two disk softraid1. disk sda is die, and replaced disk. and reboot now, copy partition table sdb to sda ok. next step copy boot record sdb to sda ok. finaliy add sda in ...
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41 views

Best way to remove drives from MDADM raid array

I have a situation with a RAID array; I'm concerned that the drives in the array are going to fail soon, and given their age, I would rather replace them sooner than later. The problem I have, is ...
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2answers
64 views

mdadm - RAIDs of partitions or partitions of RAID?

If using entire drives for an mdadm RAID which will be the boot device as well, is it more correct / standard to: 1) Configure the RAID out of partitions that encompass the whole drive (like ...
2
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1answer
130 views

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 ...
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1answer
41 views

RAID1 write penalty using mdadm - what's the cause?

When doing some performance tests writing to a SSD-based 3-way RAID 1 mirror powered by mdadm, it appears we suffer a significant write penalty of about 2.2x slower than doing the same test on just ...
1
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1answer
65 views

Power outage during RAID1 build [closed]

I was 60% complete building a two-disk RAID1 on my Ubuntu 14.04 server with the command sudo mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sdb1 /dev/sdc1 when I accidentally ...
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2answers
84 views

How to tell mdadm to use a partition as/instead of a block-device?

I have four 500GB disks which were set up as a Linux Software-RAID 5 volume during the Debian install (next to the system drive which is a SSD). One of the drives (sda) went bad and now I am trying to ...
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1answer
58 views

How/When to physically remove a failing harddrive after replacing it in a Linux RAID?

I have a Linux software RAID-1 with mdadm. Similar to this question ("How to safely replace a not-yet-failed disk in a Linux RAID5 array?"), I want to replace a disk in a the raid. My question might ...
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0answers
77 views

Growing RAID0 to RAID5 sync delayed

I've recently switched my NAS with a single 4 TB disk to a RAID setup, with the goal of implementing a 3-disk RAID5. To do this without a 4th disk and without loosing my data, I first set up the 2 new ...
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75 views

Q: MDADM mismatch_cnt > 0. Any way to identify which blocks are in disagreement?

Okay. After a routine scrub, my MDADM RAID5 is reporting mismatch_cnt = 16. As I understand, this means that while no device reported a read error, there are 16 blocks for which the data and parity ...
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1answer
56 views

Is it possible to recover a RAID 5 in this case?

Is it possible to recover a RAID 5? After losing the "/proc/mdstat" and run by mistake "mdadm --create --verbose /dev/md0 --level=5 --raid-devices=4 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1" instead of ...
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1answer
247 views

Can't mount my hard drive

When I try to mount one of my hard drives, it can't locate the folder with the hard drive. This is the output for the command df: Filesystem 1K-blocks Used Available Use% ...
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2answers
237 views

mdadm RAID6, recover 2 disk failure during reshape

I was reshaping my array from 10 disks to 11 to a degraded state (drive I want to add already has data on it, but nowhere to put it). 2 drives disconnected while it was running (power issue). Is it ...
0
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1answer
92 views

Write cache settings not working

I am using Debian 8.0 x64 with 72 GB of RAM with 4 drives configured as software RAID 0. Linux s1 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1 (2015-05-24) x86_64 GNU/Linux I tried setting dirty ...
0
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2answers
577 views

mdadm, RAID5 all disks marked as spare, won't start

RAID5 config with mdadm and 4 disks After some incidents, eg one of the drives was lost, had to reboot the server and rebuild the array, my raid is in a funny situation cat /proc/mdstat ...
0
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0answers
104 views

mdadm and LVM high load and IOwait

I've got a new CentOS 6.6 server with 2 HDD with mdadm & LVM. As I've used the CentOS install CD I assume everything should be aligned properly. I've just written a KVM image to a LVM LV using dd ...
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336 views

Mount a NTFS Raid0 disk under linux debian

In my new laptop I have a a RAID 0 configuration with a normal disk and a smaller SSD drive. I have removed the dvd bay and replaced the dvd player with a 256 GB SSD drive where I run linux debian. I ...
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259 views

RAID 5 reshape freeze

I recently added a new disk to my RAID5 array and started growing it. Absent minded as I am I rebooted the server during this reshape process I as another program was hung and blocking some ports. ...
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1answer
154 views

Proper way to identify member devices in mdadm.conf

My current mdadm.conf looks like: $ cat /etc/mdadm/mdadm.conf DEVICE /dev/sdb1 /dev/sdc1 ARRAY /dev/md0 metadata=1.2 spares=0 UUID=357ff7cc:55e78d18:9fc7917b:f5b253f2 MAILADDR me@example.com Since ...