A linux utility used to manage software RAID devices.

learn more… | top users | synonyms

2
votes
0answers
31 views

CentOS 7: RAID 1 high I/O wait

I am running CentOS 7, with RAID 1 (md) on the hard drives. I have the partitions set as shown below. md0 -> root (sda1, sdb1) md2 -> swap (sda2, sdb2) md3 -> misc (sda3, sdb3) on md3, I ...
0
votes
0answers
36 views

RAID0 worse that write speeds of hard drives independently

So I have two hard drives one connect with SATA and one with USB3.0 SATA (/dev/sdc1): Apple HDD Toshiba USB (/dev/sde2): Western Digital Technologies, Inc. Elements SE Portable ...
1
vote
1answer
22 views

Convert a non-boot single HDD to RAID 1 without deleting it

I bought a second HDD identical size as the one I already have. My goal is to add it to the existing one as a mirror (RAID 1). But I don't have enough space on a system SSD to move data there. So I ...
0
votes
0answers
15 views

Applying a patch to mdadm

I have configured RAID 6 using mdadm, and after trying to add a new disk to the ARRAY (replacing a faulty one), I am receiving the following error: mdadm --manage /dev/md0 --add /dev/sdi mdadm: ...
2
votes
1answer
34 views

Is it possible to create a mdadm RAID10 with both near and far layout options?

How do you create a mdadm RAID10 with both near and far layout options? The wiki indicates it is doable. The "near" and "far" options can be used together... The man pages for mdadm don't ...
3
votes
2answers
90 views

Install mdadm without postfix in ubuntu trusty

I want to build a RAID system on top of Ubuntu Trusty. When I do apt-get install mdadm A screen pop up asking me to configure postfix. Because I will run this installation in automation script. Is ...
0
votes
0answers
24 views

Centos 7.2 Convert single LVM to RAID Mirror Reinstall BootLoader

I am trying to convert a single-drive Centos 7.2 installation with LVM into a two-disk mdadm mirror with mrrored LVM. I was able to follow the excellent instructions at: ...
0
votes
0answers
16 views

mdadm does not automount raid0 disks under /media/storage

I've beat my head against this issue all night and I can't seem to wrap my head around it. I've recently installed Linux Mint 17.3 Mate to replace my Windows 10 machine and after some tinkering I've ...
1
vote
0answers
29 views

Debian boot with encrypted disks: RAID is not assembled

Situation I am running Debian 8 on my machine. The disk setup is as follows: # lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 55.9G 0 ...
3
votes
0answers
140 views

How do I (re)build/create/assemble an IMSM RAID-0 array from disk images instead of disk drives using mdadm?

The question: Using Linux and mdadm, how can I read/copy data as files from disk images made from hard disks used in an Intel Rapid Storage Technology RAID-0 array (formatted as NTFS, Windows 7 ...
0
votes
0answers
32 views

Mount existing RAID 5 to Open Vault Media but cannot see any file

I have an existing mdadm RAID5 pool with 3 disks running on Debian. When I connect this RAID5 pool to Open Media Vault (OMV), OMV recognise the pool and all information: disks, usage, free space.... ...
3
votes
2answers
41 views

Adding new devices to an mdadm raid10 - new device has fewer sectors

I'm trying to add two new drives to grow a raid10 created with mdadm v3.4 on debian testing with kernel 4.4.6-1. The problem is that the new drives I have have just a few sectors less that the ...
0
votes
1answer
20 views

Automate replacing failed disk in software RAID

Can mdadm automatically recognize a plugged disk as a spare, partition it and add? My config: [root@okvmh2 ~]# lsblk -a NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 ...
2
votes
1answer
163 views

mdadm RAID - Restart during Grow (Shrink) reshape - not working (stuck)

I have a linux software Raid6 array (mdadm). I grew it from 6x4TB disks (16TB usable) to 7x4TB (20TB usable). The reshape went fine, but when I did resize2fs, I got the fairly well known issue of ...
1
vote
1answer
31 views

Hard drive failure at service provider - how to restore/remount data from/on Raid

First I am not a server administrator - and am volunteering to help a non-profit with a crisis. I start from the beginning. The non-profit has a dedicated server contract with 1&1 internet. On ...
1
vote
1answer
101 views

md raid not mounted by dracut

Background I'm running Centos 7. Originally, it was running on a single disk that looked something like this: 1 200M EFI System (/boot/efi) 2 500M Microsoft basic (/boot) 3 465.1G ...
2
votes
0answers
158 views

Install CentOS on RAID (manually) on UEFI system

I'm struggling with the manual configuration of a RAID1 + RAID10. I'm trying the procedure on a VM (VirtualBox 5.0.14 r105127) on OSX 11.10.3. The strategy I took is: The complete set of commands I ...
2
votes
1answer
248 views

mdadm: no devices listed in conf file were found - Debian 8 with GPT

I have a Debian Jessie (3.16.7-ckt20-1+deb8u3) system with RAID1 on 2x 3TB hard drives. Grub can't be installed into MBR on drives >2TB, thus I have GPT with 1MB bios partition: Device Start ...
1
vote
0answers
55 views

Why is uEFI firmware unable to access a software RAID 1 /boot/efi partition?

BIOS firmware can boot a BIOS formatted /boot partition installed on a software RAID 1 pair no problem. It can even boot from a /boot installed on LVM volume that lives on a software RAID 1 pair. But ...
3
votes
2answers
57 views

create raid1 from existing lvm local volume

I have an existing LVM, with one physical drive (say /dev/sdb), and one volume group (say volgrp1), here I have three logical volumes (say lvSys, lvHome, lvSwap). Now I worry about my data and by a ...
1
vote
1answer
243 views

Dependency failed for mount after dist-upgrade

Last weekend, I ran an apt-get dist-upgrade on a home Debian 8.3 system, and was surprised to see that it entered emergency mode on the next boot. The server in question runs LVM on top of a mdadm ...
1
vote
0answers
40 views

MD RAID 5 module doesn't load at boot

I recently upgraded my NAS to kernel 4.4 and now my md raid 5 array doesn't assemble itself at boot. dmesg reveals this: [ 2.299666] md: personality for level 5 is not loaded! and doing lsmod | ...
0
votes
1answer
54 views

raid5 array reassembles as raid0

I found simmilar problem here: Missing mdadm raid5 array reassembles as raid0 after powerout, but mine is a bit different. Here too my raid5 reassembles as raid0, but i don't see any of my devices ...
1
vote
0answers
73 views

Ubuntu Server: How to make bootable bios_grub RAID device?

I have a stable Ubuntu (14.04.3) Server-powered file server that I have set up, and want to set up a RAID10 array for it. For reference, I have been following this guide so far, but using RAID10 ...
3
votes
0answers
42 views

What chunks are mismatched in a Linux md array?

This is a repost of a question I asked on ServerFault and was automatically deleted for lack of activity. Let's hope it will have better luck here. After performing a "check" (by writing check to ...
1
vote
0answers
94 views

lsblk shows non-existent md partitions after reboot

I'm getting weird behaviour while setting up an mdadm RAID1 array on debian 8.2. After I set-up the array, lsblk shows: simon@debian-server:~$ lsblk NAME MAJ:MIN RM SIZE ...
1
vote
1answer
16 views

What happens if Host OS of MDADM md0 crashes

So I am debating getting software RAID. But I am trying to reduce the single point of failure problem. I don't think hardware raid is an option as I can't afford a high-end adapter, and I think I like ...
0
votes
0answers
16 views

mdadm raid 1 array superblock can't be ready

I have a ubuntu linux box, with a raid mirror, 2x3TB using mdadm It's not the system disk, but a raid 1 mirror that contains some files I really need to keep. After power cut, restarted and now ...
2
votes
1answer
26 views

Is there a way to rebuild only part of a disk in an mdraid5 setup?

Last night I accidentally used dd to overwrite the first ~20GB of a drive in a RAID5 array. When I noticed, I repaired the array with $ mdadm --fail /dev/md127 /dev/sdb $ mdadm --remove /dev/md127 ...
1
vote
0answers
57 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 an already replaced device unrelated to the array, after every reboot the array starts ...
1
vote
0answers
38 views

RAID1 superblock recovery

I have a big issue with my RAID1 array. I transferred my RAID1 (mdadm) to a new PC, but when I was installing it, I rebuilt the array as a RAID0. No data has been written to the disks. When I try ...
1
vote
1answer
28 views

What happens if my RAID fails while the swap is on it?

Today I removed swap from the system drive on my Debian. And created a swapfile on md0. So, I have a RAID1 array for data and a swapfile (the only swapfile). The system with boot partition is on ...
0
votes
2answers
44 views

I'd like to verify mdadm RAID1 is completely fine

Is there some mdadm --verify similar command, which would read all sectors of both disks in RAID1 to truly verify it's fine?
1
vote
0answers
12 views

How to make mdstat ignore specified devices

I have a hypervisor with KVM that uses zvols for virtual machine storage. One such virtual machine was moved from a physical one and has software RAID inside it. Zvols are detected as block devices on ...
4
votes
1answer
123 views

Why does mdadm believe my raid1 “has failed so using --add cannot work”?

TLDR: Trying to add a blank partition to a degraded RAID1 with mdadm 3.3.2 (Debian Jessie) fails, saying the (perfectly working!) array has "failed" and "--add cannot work". Is it telling me of a real ...
5
votes
1answer
387 views

Configuring a mdadm RAID-1 on SSD and HDD

I need to configure a RAID-1 on one SSD and one HDD. Both SSD and HDD has some preinstalled software, which I don't need so both can be fully wiped if that is any advantage. My research so far lead ...
1
vote
1answer
246 views

FIx RAID configuration after upgrade to Debian/Jessie with ICH9 chipset

I upgraded from Squeeze to Wheezy without problems. But after upgrading to Jessie the system cannot boot anymore (using LILO). LILO ERROR: Duplicated Volume ID O 24.1 Loading Linux ....(snip) BIOS ...
3
votes
2answers
226 views

MDADM RAID 0 Failure

Last night I noticed my system clock on my Ubuntu Server was 5 minutes fast so I ran an 'ntpdate pool.ntp.org' command and went to bed. This morning I noticed that SAMBA shares were not working. ...
2
votes
1answer
679 views

mdadm: /dev/md0 assembled from 3 drives - not enough to start the array

I had a drive in my raid5 fail a while back. I believe the problem was due to a power failure at the time, but originally thought it might be the hard drive controllers on the motherboard. (this is ...
1
vote
2answers
147 views

how to access data on RAID10 (consisting of 2 disks) using only 1 disk?

A long time ago I setup a RAID consisting of 2 disks. I wanted more than else safety/redundancy and indeed I think I wanted a RAID1. Now I have only access to one of those 2 disks and looking at it I ...
0
votes
0answers
59 views

raid10 “recovery aborted due to read error” drives being marked spare

I'm trying to recover my RAID10 array. All devices are plugged into a PCI controller that I've been using for a number of years now. I just replaced all of the drives in the system, as they all seemed ...
1
vote
1answer
91 views

mdadm RAID10 - change broken disk

Tonight my server stopped answering to ssh, ping, so I drove to the server room. Server did not respond to keyboard (even Ctrl-Alt-Del), there was no data on screen (it was black, no symbols on it), ...
3
votes
1answer
208 views

RAID mdadm virtual disk too small

sudo mdadm --build /dev/md0 --level=linear --raid-devices=3 /dev/loop0 /dev/sda1 /dev/sda2 After running the above command, /dev/md0 is smaller than /dev/loop0 + /dev/sda1 + /dev/sda2. Why is that ...
3
votes
3answers
43 views

Replacing a disk to RAID5 failed

I removed a faulty disk from my RAID5 with mdadm --manage /dev/md0 -r /dev/sdd1 and replaced it with a new one. I tried to add it with mdadm --manage /dev/md0 -a /dev/sdd1 but it's only added as a ...
5
votes
1answer
109 views

Is it sensible to use multiple LVM layers with mdraid

I'm building up a home server that will be used for a handful of different things. I'd really like to try a Btrfs raid 1 array for a large data store, but I'm using CentOS 7 (older kernel although ...
2
votes
0answers
99 views

Boot GRUB2 with Degraded RAID5

I am building a custom NAS with Debian Jessie. Has three 4TB hard drives in a software RAID5 configuration. Works perfectly when all three drives are present. I am trying to test what happens when if ...
1
vote
1answer
255 views

mdadm raid filesystem differs from disk filesystem

I have created a raid 5 using mdadm on Debian. I used 2 new and 1 "old" disks. The old one had ext3 before. Using "parted -l" I noticed the raid has ext4 as filesystem but the old disk has ext3. I ...
1
vote
1answer
308 views

RAID boot drive not found after mdadm upgrade

I was having trouble getting a new RAID array to assemble on startup, and before anyone responded to that post, I tried updating mdadm, but this ended up taking a very long time because of all the ...
2
votes
2answers
3k views

New RAID array will not auto assemble, leads to boot problems

I had just asked this question where I was unable to boot after installing a new RAID1 Array. I was able to get to the terminal, but once I sorted that out I realized that my problem isn't so much an ...
2
votes
3answers
140 views

mdadm refuses to add second identical disk to array

I have a RAID 1 array which is in a degraded state and want to add another drive to it. # mdadm --detail /dev/md1 /dev/md1: Version : 1.2 Creation Time : Fri Mar 21 17:23:00 2014 Raid ...