Questions tagged [raid5]

The tag has no usage guidance.

23
votes
3answers
18k views

How to safely replace a not-yet-failed disk in a Linux RAID5 array?

I have a software RAID5 array (Linux md) on 4 disks. I would like to replace one of the disks with a new one, without putting the array in a degraded state, and if possible, online. How would that ...
19
votes
2answers
56k views

How to recover a crashed Linux md RAID5 array?

Some time ago I had a RAID5 system at home. One of the 4 disks failed but after removing and putting it back it seemed to be OK so I started a resync. When it finished I realized, to my horror, that 3 ...
8
votes
6answers
6k views

Pros and cons of software Parity-RAID (e.g. RAID5)

I was recently told about some problems concerning Parity-RAIDs without a non-volatile cache. More exspensive HW-controllers do have battery-powered caches to finish write-operations in case of power ...
4
votes
4answers
3k 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 kernel:...
3
votes
5answers
908 views

Linking Intel RAID 5 partitions to boot disk

I have a 5-disk Intel RAID 5 along with a 6th boot disk with /, /boot, and swap. What I was planning to do was mount the Intel RAID partitions (which I've added with fdisk) so that the 6th disk /home,...
3
votes
2answers
416 views

raid5 exchange 1 of 3 harddrives [duplicate]

I want to exchange a Harddrive which is in a pre-failing state, (some reallocated sectors) which is used in a raid5 array with 3 disks (software raid with mdadm). Is it possible to set a new ...
3
votes
2answers
259 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 disks,...
3
votes
1answer
285 views

mdadm RAID5 cannot be assembled

Yesterday I wanted to do some maintenance on my server. I shut it down pressing the powerbutton once which works just fine every time. After the server was still shutting down after 10 minutes I ...
3
votes
1answer
95 views

How to restore RAID5 Array

I have a RAID5 array consisting of 3 identical 2TB drives. Suddenly GRUB wouldn't boot anymore and gave the error out of disk. Eventually booted a livecd and ran some mdadm commands: mdadm --examine ...
3
votes
1answer
395 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 ...
2
votes
1answer
2k views

How to mount software RAID-5 created by Windows under Linux?

At our university we have a Windows FTP server that was implemented with software RAID-5 technology, but we decided to migrate to Linux. How can we mount and modify it under Linux?
2
votes
1answer
2k views

How to create a 3x3TB RAID 5 array without losing data from 2 of the drives?

I currently have 2 3TB HDDs, one that is always almost full, and another with ~200GB free. I would like to purchase an extra 3TB drive and setup a RAID 5 array, but I am concerned about losing the ...
2
votes
1answer
631 views

Unable to mount raid 5 array (mdadm), with no drive errors

I have a 3 drive raid 5 array using the following disks: /dev/sda /dev/sdc /dev/sdb I'm no longer able to mount the drive with the following error: sudo mount /dev/md0 /mnt/md0/ mount: wrong fs ...
2
votes
1answer
124 views

ubuntu - raid partition capacity unchanged after RAID1 to RAID5 to RAID6

I had a 2 disk RAID 1 partition. I added a device and converted it to RAID 5: mdadm --add /dev/md3 /dev/sdd2 mdadm --grow /dev/md3 --level=5 --raid-devices=3 Then added another device and converted ...
2
votes
1answer
545 views

BTRFS, RAID5 and the minimum number of drives required

It's been my understanding that in order to have a RAID5 setup, one would need to incorporate a minimum of three drives. Basically (and probably poor paraphrasing) two blocks of data and a block of ...
2
votes
2answers
749 views

Raid5 Device Has Less Space Than Expected

I have 3 3TB drives, and have raid5ed them together. I would expect to get a resulting device around 6TB. The command I used: mdadm --create md0 --level=5 --raid-devices=3 /dev/sda1 /dev/sdb1 /dev/...
2
votes
1answer
1k views

Migrating from hardware to software RAID

I have an old PCI-X controller running 8 drives in RAID 5. I'd like to dump the controller and go to software RAID under Ubuntu. Is there a way to do this and retain the data from current array? EDIT:...
2
votes
1answer
9k 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 a ...
2
votes
2answers
105 views

challenging failed raid5 recovery

I have a personal raid 5 array that is in rough shape. The failed array has eight 2 TB drives that were built up over time in my n-2 desktop machine. The array is from an in-house computer that ...
2
votes
1answer
88 views

How can I migrate my Ubuntu installation from LVM2 to RAID5?

I stumbled upon this question, but I do not think this is a duplicate since I'm under the impression that the OP in this question is not running under a live session. I, on the other hand, have ...
2
votes
1answer
181 views

How to add RAID5 to existing crypto-LVM?

I recently installed Debian Wheezy and let the installer guide partition the disk using a whole partition with encryption (LVM). Later on I've added four disks and setup RAID5 on them (using mdadm). ...
2
votes
1answer
999 views

IO Error on RAID5 member. What to do about bad blocks?

I recently got an IO Error on one of my RAID5 members; on a 3 disk fakeRAID array. I didn't notice at the time - there was only a message in /var/log/kern.log - so I had continued running the machine ...
2
votes
1answer
146 views

Worrisome HD related messages after power outage

Had a power outage two weeks ago on my BSD server that my UPS decided then was a good time to fail. Just fired it up this evening only to have the following errors show during what I would assume is ...
2
votes
0answers
204 views

How to recover data from synology Raid 5?

My old synology server (cs407s), died. So I'm trying to retrieve the data from the disk. I have tree disks from RAID 5. I tried to mount the disk on computer running grml. # lsblk sda 8:0 0 ...
2
votes
0answers
1k views

Arch Linux Server: How to spin down HDDs in a BTRFS Raid5 configuration?

This is my first question here; after extensive research I had to reach out for help. I’ve build a home server based on Arch Linux. It basically has two main purposes: running a Plex Media Server and ...
2
votes
2answers
2k 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 ...
2
votes
0answers
389 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 ...
2
votes
1answer
131 views

Same file with different content on every read [closed]

I have a problem with a filesystem here on a storage machine. We noticed, that many of the data that comes out of the systems seams to be corrupt, but only with minor problems like CRC errors with ...
2
votes
0answers
158 views

Rebuilding a raid5 array from images

I have an 8 disk possibly raid5 array that was part of a fried NAS, the whole thing uses pdc20265 promise chips and some kind of embedded system on a small ide board. No clue if the board is anything ...
1
vote
2answers
43 views

Can I Increase raid 1 capacity by changing to raid 5?

My initial raid setup was 2x2TB RAID 1 using mdadm. I have bought a 3rd 2TB drive in the hopes to upgrade the RAID's total capacity to 4 TB using mdadm. I have already run the following two ...
1
vote
1answer
474 views

Add linux md raid write journal to and existing array

I have a raid5 array with quite large disks, so reconstruction is really slow in case of a power outage. Thankfully, there is the --write-journal option for linux md raid. The man page lists the --...
1
vote
2answers
650 views

Disk I/O performance issue [closed]

I have a Dell PowerEdge R820 server which is under maintenance by other third party. There are 6 SAS (10K RPM, 6gbps) disks and they are configured as RAID 5 using PERC controller. Currently I am ...
1
vote
1answer
1k views

Raid5 + LVM2 + grub2: final config and boot

I have a one disk, no RAID, no LVM system based on Debian Squeeze (my old system). I created a RAID array (RAID 5, 4 HDDs) with mdadm (my new system). I installed LVM2 on the new system and ...
1
vote
1answer
299 views

mdadm, invalid RAID level?

I'm trying to create RAID 5 according to this tutorial. But, when I run mdadm -C /dev/md0 -l=5 -n=4 /dev/sd[b-e]1, I get this error: mdadm: invalid raid level: =5 Here's the output of mdadm -E /dev/...
1
vote
1answer
1k views

Repairing a RAID5 array

I'm trying to repair a RAID5 array, consisting of 3 2TB disks. After working perfectly for quite some time, the computer (running Debian) suddenly wouldn't boot anymore and got stuck at a GRUB prompt. ...
1
vote
1answer
1k views

An existing mdadm RAID5 is not mounting, Either a problem drive or Superblock

I have 4 x 3TB NAS setup as RAID5 which has been working great for almost a year. After a recent abrupt shutdown (had to hit the power button) the RAID will no longer mount on boot up. I've run: ...
1
vote
2answers
146 views

MDADM - adding a disk to RAID5 with slightly less sectors

Basically I have raid 5 with three disks that are 2TB each. I bought 2 extra 2TB drives however they are few sectors smaller on a newer model - old drives are no longer sold. When I issue /dev/md0 ...
1
vote
2answers
66 views

Building a network storage server, trade-offs of different RAID configurations?

I want to install a Linux server in my house to be able to share documents and multi-media files between every devices here. The machine I have has 3 HDD slots, I need at least 3.5 TB of storage and ...
1
vote
1answer
452 views

How do I force a LVM2 RAID5 logical volume to span across an additional physical volume?

I'm testing LVM configurations for the purpose of building a home NAS with Ubuntu Server 16.04 LTS. I first added three 20GB disks to my machine (sdb, sdc, sdd), created three physical volumes grouped ...
1
vote
1answer
1k views

HP SmartArray RAID5 recovery on linux

This is a long time in the making, and I've finally got it working so I thought I'd share this with as many people as I can in case they're in a similar situation. Long story short - HP SmartArray ...
1
vote
1answer
456 views

is it possible to recover a raid 5 array by using usb enclosures?

I had a RAID 5 (Linux software RAID) server which recently decided not to boot anymore. It seems to be a motherboard problem possibly due to not being protected by a UPS during a power failure. It ...
1
vote
1answer
47 views

rebuilding mdadm raid5

I've dusted of a machine of which I want to repair an mdadm raid5 that I messed up. First the raid5 was 3 disks. A spare was added, just before one of the three started to fail. Spare one got used and ...
1
vote
1answer
122 views

How do I work out what's trashing my RAID?

I have an x86_64 Ubuntu 17.10 install (stock 4.13 kernel) with an SSD and three 1TB WD HDDs which each have a 750GB partition that's used in a 1.45TB RAID5 array. The SSD has my / on it, and the RAID ...
1
vote
0answers
289 views

Unable to mount raid 5 (Intel fakeRaid)

I recently corrupted my linux distro. I then reinstalled Ubuntu 16.04.3 and after setting it up, I have been unable to mount my Raid 5 setup after extensive troubleshooting. Note even after the ...
1
vote
0answers
239 views

need to rebuild mdadm raid5

I've got an mITX nas running Arch with a Raid5 mdadm softraid. Lasttime it booted correctly Aug 19 11:30:21 nas kernel: md/raid:md127: device sdc1 operational as raid disk 1 Aug 19 11:30:21 nas ...
1
vote
1answer
293 views

Recover RAID5 array after partitions deleted

I have (had) a large RAID5 array (3x8TB) up and running on Ubuntu 16.04 using the guide on the following page: https://www.digitalocean.com/community/tutorials/how-to-create-raid-arrays-with-mdadm-on-...
1
vote
1answer
183 views

How to recover a raid5 on nas with a failure partition? [closed]

I have a RAID5 on SYnology nas system that has crashed. In first the system prevent to one disk has been removed from the raid with the degraded status. After a shudown to unplug the disk and restart ...
1
vote
0answers
32 views

Can 99-raid-check weekly cronjob be scheduled to run in increments?

I have a raid5 on UNIX. Can I somehow automatically schedule the weekly 99-raid-check to run in increments? During the day it affects the performance, so I don't want it to be doing its check during ...
1
vote
1answer
748 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
196 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 [UU_]...