Tagged Questions

A linux utility used to manage software RAID devices.

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1
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2answers
16 views

Raid 5 not starting

I had a raid 5 with 3 disks in my old computer, but the motherboard died. I put all the disks in a New computer, but the raid doesn't want the start anymore. When booting the pc, i can see all ...
0
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1answer
31 views

mdadm RAID 5 and parted unrecognized disk label

I have three 3 TB drives that I am attempting to put together into a RAID 5 setup with mdadm, but I am running into some issues. (Actually, I have four 3 TB drives I will be using, but one of them ...
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0answers
12 views

Mdadm not adding all disks to raid

A couple of years ago, I installed a raid 5 with mdadm on a fedora box. The old hardware died recently, and I have put the boot disk in a newer desktop pc, and added the thee raid disks via usb. So ...
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0answers
25 views

Degraded RAID1 array boots with one drive, not with the other

UPDATE It seems initramfs fails to properly mount the array. If I stop and reassemble them, they works: mdadm --stop /dev/md124 mdadm --assemble --run /dev/md124 /dev/sda6 Maybe initrd tries to ...
3
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1answer
101 views

Grub fails to install - Debian Wheezy with mdadm RAID1 and GPT partition table

I've been trying all day to get my new Wheezy install completed but it fail to install Grub every time. I'm using x64 netinstall iso. Here is my partition table: Model: ATA ST3000DM001-1CH1 (scsi) ...
1
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1answer
39 views

Can't boot from RAID array - arrays not assembled at boot

On my lubuntu 13.10, I created a degraded RAID array, copied all the contents of the "main" disk and tried to boot from the array. I mostly followed these instructions. At boot the system does not ...
1
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1answer
42 views

Missing mdadm raid5 array reassembles as raid0 after powerout

I had RAID5 array of three disks with no spares. There was a power out, and on reboot, the array failed to come back up. In fact, it the /dev/md127 device disappeared entirely, and was replaced by an ...
0
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1answer
50 views

“Spare” disk in a 2-disk mdadm RAID1 array?

I recently had a RAID1 volume fail. It had three primary partitions in it, all participating in separate, but similarly configured VGs. This configuration comes from the fact that the machine is ...
1
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1answer
15 views

mdadm - What's the difference between --detail --scan and --examine --scan?

From man mdadm: -E, --examine Print contents of the metadata stored on the named device(s). Note the contrast between --examine and --detail. --examine applies to devices which are ...
1
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2answers
26 views

Spanning RAID over SSD and Mechanical HD

Currently I have my root (/) directory on my ssd, and my home directory on my mechanical drive. Wanting to utilize more of the ssd and hopefully get a speed benefit, I was considering spanning across ...
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0answers
16 views

File transfer between SSD and RAID array uber-slow

It's really simple: this server has an SSD for the main drive, and a RAID array (mdadm) for storage. Intermittently, it has a problem writing to the array: the write speeds slow down to the point ...
0
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1answer
21 views

A SparesMissing event had been detected on md device /dev/md0

I'm getting the following mail every day on a server: This is an automatically generated mail message from mdadm running on <host> A SparesMissing event had been detected on md device ...
1
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3answers
36 views

Linux SW RAID and physical volumes

In each guide about software RAID in Linux, I could find online I see that people usually create/assemble RAID devices using partitions, like: mdadm --create --verbose /dev/md0 --level=5 ...
2
votes
3answers
399 views

CentOS 7 created mdadm array disappears after reboot

I created a raid1 using the below disks and command: $ ls -l /dev/disk/by-id/ata-ST3000* lrwxrwxrwx 1 root root 9 Sep 19 07:27 /dev/disk/by-id/ata-ST3000DM001-9YN166_Z1F04NR1 -> ../../sdc ...
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0answers
238 views

How to make Intel fake RAID 0 volume appear on boot with Ubuntu 14.04 in a multi-boot environment?

I have a computer with a Gigabyte GA-Z97N-Gaming 5 mainboard, a 256 GB drive for booting and two 3 TB drives meant to use in a RAID 0 setup with both ext4 and NTFS partitions. We are planning running ...
0
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1answer
32 views

Data integrity after GPT restore on Mdraid configured disk

I've restored backup GPT headers on previously GPT partitioned disks that are member of a Linux software raid (mdraid). This was done because partprobe reported corrupted headers. Now actually ...
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0answers
18 views

MDADM Array Detection Slowing Down Boot - Why?

I have an AMD64 Gentoo (running systemd) build with a RAID0 root and some other arrays (RAID1 boot, RAID1 home etc..). The boot process is being slowed down quite dramatically as mdadm searches the ...
2
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1answer
47 views

Raid 5 rebuild with wrong stripe size & no failed disks - is data lost?

I'm curious if there are hidden complexities to RAID5 and RAID5 rebuilds. My understanding is that (in a 3 disk array) a rebuild would just directly compute the parity of disks 1 & 2 and write ...
0
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0answers
330 views

What are the steps needed to get Redhat/Centos 7 to boot from an mdadm RAID?

I've spent a day on this. Figured it was time to ask. In the end I couldn't get around "Bad magic number in super-block ..." On an average install, my sda exits setup as an EFI. I'm cool with that ...
2
votes
1answer
75 views

Why is so much of my new ext4 filesystem already marked as used?

I have just created a new raid 5 array using 3 4TB drives (aiming for 8TB of space) on an ubuntu system. While I had a few issues getting started, I believe I have set it up correctly and I have ...
2
votes
1answer
71 views

RAID resyncing automatically?

I rather randomly checked the status of my RAID arrays with cat/proc/mdstat and realized, that one of my arrays seems to be resyncing: md1 : active raid1 sdb7[1] sdc7[0] 238340224 blocks [2/2] ...
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2answers
60 views

mdadm metadata: should i take precautions to prevent superblock overwrite?

Situation: I'm creating a new RAID1 array using mdadm. I won't be using additional layers, such as LVM or dm-crypt. I've noticed that metadata version 1.2 is now the default. I understand it's the ...
0
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1answer
2k views

mdadm raid doesn't mount

I have a raid array defined in /etc/mdadm.conf like this: ARRAY /dev/md0 devices=/dev/sdb6,/dev/sdc6 ARRAY /dev/md1 devices=/dev/sdb7,/dev/sdc7 but when I try to mount them, I get this: # mount ...
0
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1answer
39 views

Recovering a (not yet created) RAID5 with URE (Unrecoverable read errors)

I wan't to create a RAID5 array at home, the OS is Linux (Kernel 3.15.7) and the array will be created with mdadm. I wan't to create the array with eigth or ten 1TB discs. Let's assume a single drive ...
2
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1answer
114 views

mdadm inconsistencies when run programmatically

Update #1: I just gave an extra layer of testing, writing a shell script (.sh, #!/bin/bash) and a php script to be executed by php's cli. Bash works. It seems that it's not the Apache's HTTP ...
2
votes
3answers
136 views

Reassemble mdadm-raid5

A friend of mine has a mdadm-raid5 with 9 disks which does not reassemble anymore. After having a look at the syslog I found that the disk sdi was kicked from the array: Jul 6 08:43:25 nasty ...
3
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1answer
103 views

RAID-1 mirror has become a single hard disk

I have an HP N40L microserver, with 2 identical drives, I used the system to hardware-RAID them as a mirror. I then installed mint on the system about a year ago. This has been running perfectly, ...
3
votes
1answer
129 views

How to speed up migration from Raid 5 to Raid 6 with mdadm?

Today I started the migration of my Raid 5 to Raid 6 by adding a new disk (going from 7 to 8 disks, all 3TB). Now the reshape is in progress: Personalities : [raid6] [raid5] [raid4] md0 : active ...
1
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0answers
22 views

Is it reliable to assemble md from two machines at the same time

Say we have the same disks accessible from two machines. I want to do assembling md from two machines. Is it possible/reliable ? The disks are connected through SAS. All I need to have is reliable ...
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0answers
62 views

Moved Raid from NAS box to PC running Ubuntu hdparm shows drives frozen

So I had a RAID5 setup in a Partriot S4 Javelin (a NAS box). I'm now migrating it to a proper server running Ubuntu 14.04. NOTE: There are 4 drives. All the drives show up in Ubuntu. Two show ...
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0answers
228 views

Understanding iostat with Linux software RAID

I'm trying to understand what I see in iostat, specifically the differences between the output for md and sd devices. I have a couple of quite large Centos Linux servers, each with E3-1230 CPU, 16 GB ...
2
votes
2answers
55 views

mdadm - exclude drive from monitor

I have created a RAID 1 array with a single drive (in order to add a second drive later). # mdadm --create /dev/md5 --level=1 --raid-devices=2 /dev/sdc1 missing But, I execute /sbin/mdadm --monitor ...
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0answers
347 views

Help with lost software RAID5 on CentOS 6.5

I've been searching for hours and giving up / too scared to delete all my data. I have a file server running CentOS 6.5 which has 4 WD RED 2TB drives (all > 1 year old) in software raid 5 with mdadm, ...
1
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1answer
75 views

mixed raid types

I am about to reinitialise my (SW) raid array. Previously the array was raid5 with 4 disks. I've removed one disk in order to install a new additional (larger) drive. What I'd ideally like to do is ...
1
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0answers
133 views

How do you migrate from dmraid to mdadm on a working 14.04?

I installed 14.04 LTS the other day on two Samsung 840 Pro's in RAID0 on my Intel FakeRAID BIOS setup (NO efi). It is running great, however during the initial boot the system seemed to have a broken ...
3
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0answers
59 views

RAID6 scrubbing mismatch repair?

You can initiate a scrub of a mdadm array with echo 'check' > /sys/block/mdX/md/sync_action, and if a bad sector is found, it'll rewrite it automatically (from a mirror or from parity information ...
2
votes
1answer
100 views

How do I know if software raid is running or setup correctly

This is what I pulled: mdadm --monitor --scan -f --pid-file=/var/run/mdadm/mdadm.pid cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sda1[0] sdb1[1] 262080 blocks super 1.0 [2/2] ...
6
votes
1answer
78 views

Should I use `mdadm --create` to recover my RAID?

There's this guy that keeps telling me that we shouldn't use mdadm --create to recover our RAID arrays, that it's worse than evil, is an error. Why is that? I mean I should get my RAID working again, ...
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0answers
282 views

mdadm raid 5 missing partitions after reboot

I had a working raid 5 array that had a whole debian install on it (I set it up during a debian install). I'd been using it a couple of days, all was fine, but since I created it during debian ...
12
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3answers
2k views

Difference between UUID from blkid and mdadm?

Can someone explain the difference between the UUID's reported by blkid and mdadm? On one of our CentOS systems, for example: [root@server ~]# blkid | grep /dev/md1 /dev/md1: ...
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0answers
20 views

Linux software raid assembled “itself” with failed drive. Why?

I have two raid1 arrays: md3 (sda3 + sdb3) and md5 (sda5 + sdb5). I deliberately failed the sdb disks because I wanted to change the partition table: # mdadm /dev/md3 --fail /dev/sdb3 # mdadm ...
0
votes
1answer
253 views

Is it useful to setup RAID0 on laptop? [closed]

I have a Dell laptop, which I am going to replace the CD-ROM hub with a HDD. I am thinking if I setup a RAID0 on my original HDD and the new HDD, would I have some I/O performance improvement? ...
2
votes
1answer
67 views

mdadm: Is PROGRAM always run by the user root?

I have an mdadm-RAID and want to get notified about events, for example a failing HDD. I can use MAILADDR and PROGRAM in the mdadm config file to achieve this. I decided to use the latter. So I wrote ...
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0answers
56 views

Change Initramfs script

I made RAID 0 by mdadm'ing partition located on dmraid VIA VT6421 and Western Digital hdd. Installed Ubuntu on that RAID. Now, when I boot, I get (initramfs) ash prompt. There, I have to write mdadm ...
1
vote
1answer
218 views

mdadm : difference in metadata versions

Can anyone tell me the difference between the different metadata versions for mdadm? When I try the command mdadm --examine /dev/sda1, I can't seem to find "preferred superblocks" on version 1.2. ...
1
vote
2answers
162 views

Gentoo XEN host + EFI + MDADM + IMSM RAID5

I have a workstation with a working Gentoo setup. It uses IMSM FakeRAID (level 5) with 4 disks. Booting done without bootloader using Linux kernel EFI STUB. System works fine. Now I need to setup XEN ...
3
votes
1answer
365 views

How to open multiple LUKS volumes with key entered in initramfs?

I have a Debian 7.4 (stable) based server configured to use an encrypted (RAID1 + LVM) root partition (/boot is un-encrypted regular partition) to which I installed dropbear SSH server so I can ...
2
votes
1answer
83 views

Transfer 2 drive raid0 / lvm2 system to new drive pair

I have a multi-boot, multi-drive system that I want to transfer onto 2 bigger drives. Currently pc has 2x1TB drives with Fedora 19 running, using RAID0 drive mirroring, with LVM2 on top of the md. I ...
0
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2answers
149 views

Two arrays have slightly different array size with same size disks/partitions, why?

I created a software RAID 5 array one year ago using mdadm v3.2.x which shipped from CentOS 6.3, after few months, I moved/assembled the array to/in Fedora 19 (now Fedora 20). It had three 3TB disks ...
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0answers
138 views

RAID5 Arrary disappeard with no HW or SW changes made

I have a R-Pi running XBMC (Linux CaribNAS 3.10.24 #2 PREEMPT Mon Dec 23 05:18:12 UTC 2013 armv6l GNU/Linux) with a 3 disk raid 5 array that has been working up till yesterday when is stopped running ...