RAID solution handled by the operating system.

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5
votes
1answer
979 views

What effect does RAID stripe size have on read-ahead settings?

I'm trying to figure out the correct read-ahead values to set on a RAID10 array, and I'm wondering if the RAID stripe size should factor into my considerations. I've heard conflicting information ...
0
votes
1answer
89 views

Linux Software RAID 1 issue

I recently had a HDD failure on a SW RAID1 system (Debian 6.0) and what happened was that the active HDD looked like it had some badblocks which somehow propagated to the HDD that was still OK but it ...
6
votes
1answer
10k views

KVM guest io is much slower than host io: is that normal?

I have a Qemu-KVM host system setup on CentOS 6.3. Four 1TB SATA HDDs working in Software RAID10. Guest CentOS 6.3 is installed on separate LVM. People say that they see guest performance almost equal ...
1
vote
1answer
130 views

grub2 failing to detect md0 for /

I recently set up a raid 1 array. Both / and /boot are on md0 (sda, sdb). everything was working when it was in degraded mode before I synced the two disks together. It was booting from grub2 on ...
-1
votes
1answer
139 views

Software raid 0 with six disks performance

I have some problems with disk performance. I have 6 x WD 500Gb RE4 disks. Each disk gives 135Mb/sec throughput. All measurements are made with hdparm with options "-tT" (I know that it is just ...
0
votes
1answer
1k views

Linux software RAID60: Can I have global hot spare?

As far as I can see Linux has RAID6 and RAID0, but not RAID60. So RAID60 is emulated by creating RAID0 on top of some RAID6s. It is possible to add a hot spare to each of the RAID6s, but is it ...
0
votes
1answer
5k views

Why has ESXi 5.0 not used the software RAID configuration on my test server?

I've got a test server which was running WS 2008 Enterprise on the bare metal. It was correctly using the software RAID 1 configuration (2x250 GB disks which appeared as one disk), setup on the Dell ...
0
votes
1answer
472 views

Ubuntu server boot degraded raid

I've installed Ubuntu 12.04.1 in a new server and set up the 4 hard drives with 3 RAID 1 devices, the configuration is such that the first two drives have md0 (swap space) and md1 (/) with the third ...
0
votes
1answer
122 views

using mdadm, can I add a mirror raid over network for backup purposes?

I have a remote live filesystem I want to make a snapshot of. Using mondo it could work but it slows down the system too much. Using dump/restore could work too but I don't seem to get file ...
1
vote
2answers
330 views

Ubuntu 12.04 Server Software RAID1 - Faulty Spare - Smart Output Passed - Confused

I think I'm having an issue with one of the hard drives on my array and I'm just trying to troubleshoot what's happening. Its saying Faulty Spare and then after reboot it just says removed: ...
2
votes
3answers
306 views

Analysing Disk IO Traffic

I am running a web server (Ubuntu 11.04) that exhibits unexpected high write traffic. When the server is not supposed to write at all, the amount of write traffic is comparable to the read traffic. ...
1
vote
1answer
859 views

mdadm and blkid give different uuid

We recently replaced a hard disk in a server and reinstalled the operating system (Centos 6) The raid rebuilds itself every boot; /dev/md2 is losing a disk each time apparently. Always the same ...
3
votes
4answers
482 views

OS or Onboard software RAID?

I plan on installing Debian 6 on my server build with a E3-1270, 16GB DDR3, and 2x120GB SATA3 SSDs. But this has me wondering, should I use Intel's built-in, on-board software RAID or the OSs'? ...
0
votes
2answers
734 views

RAID disk failure - Replace disk or whole array?

I have a 5 disk Raid5 array of Western Digital Green (WD10EADS) 1TB. Raid5 is via Windows Server (software raid). One disk has failed, and it looks as though I can't get the same model replacement. ...
20
votes
2answers
6k views

Readahead Settings for LVM, Device-Mapper, Software Raid and Block Devices - what wins?

I've been trying to find a straight answer on this one, and it has proved elusive. This question and its answer is close, but does not really give me the specifics I would like. Let's start with ...
5
votes
4answers
2k views

Is it necessary to have RAID in a virtual machine?

I have a Windows 2008 Enterprise on RAID 10 running Active Directory, Hosted Exchange, and a web server on HyperV VMs. Do I need a virtual RAID for Exchange? If so, why? Edit: thanks everyone for the ...
1
vote
1answer
336 views

Is there a way to prevent a SW RAID 1 from degrading?

I have a number of Debian servers in a datacenter and from time to time I notice that the software RAID 1 was degraded. While the re-sync process starts automatically and I don't lose any data I find ...
0
votes
1answer
345 views

How do I recover from boot error when my root is on RAID and LVM? [closed]

When a (Archlinux) system that has its root on RAID and LVM is misconfigured and does not boot, what steps are needed to recover it?
-1
votes
2answers
964 views

Determining the software RAID configuration on an Ubuntu server

I have an Ubuntu box which was installed by an admin who is not with me now. I have no information on how he configured the RAID and neither no experience on setting up a software RAID on Linux ...
4
votes
1answer
382 views

3 drives fell out of Raid6 mdadm - rebuilding?

i had an mdadm raid6 array with 13x1TB drives. Within 10 minutes 3 of these drives fell out of the array... we assume bad cable to the controller card and replaced, however now we need to get the ...
1
vote
1answer
1k views

Ubuntu RAID5 Software Raid inactive - unable to boot into Ubuntu from non-raid drive

I have a server with 6 disks in it, 5 of which are in a RAID5 array. I came home from work today to find that the landlord had been through the house with a sparky, and the power had been reset. Now, ...
1
vote
1answer
1k views

Ubuntu software raid on efi, how to boot off second drive?

I'm up and running on Ubuntu server with software raid 1 with 2 500GB drives and I'm just trying to test things out. If I unplug the second drive I'm able to boot in degraded mode but if I unplug the ...
9
votes
3answers
5k views

Deciphering continuing mpt2sas syslog messages

Summary I have been getting these cryptic messages in syslog since I installed some new hardware and I can't figure out what the problem is, if it's serious, or what to do about it. They're from the ...
4
votes
1answer
922 views

Why does heavy I/O slow my server to a crawl?

I've been trying to troubleshoot a problem with I/O on my disks. The setup is as follows: OS: CentOS 5.6 Disk layout: Disks (/dev/sda, /dev/sdb) Partition (/dev/sda1, /dev/sdb1) MD Array (RAID-1) ...
1
vote
2answers
161 views

Software RAID 1 issue

I have a SW RAID 1 with 3 partitions and one of them seem not to be able to re-sync after a HDD failure/replacement. Here's some info: more /proc/mdstat Personalities : [raid0] [raid1] [raid6] ...
3
votes
1answer
959 views

Moving 4 Ubuntu software “RAID” disks to a new computer - How to make sure it works immediately?

Thinking in terms of the future, let's say I buy 4 external disks, set them up with Ubuntu Server 12.04 software RAID 1+0. Then later after some usage I want to stick them on a new computer - how do I ...
2
votes
1answer
1k views

Configuration Tuning for PostgreSQL 9.1 PostGIS 1.5 Ubuntu 12.04 Server

My server performance is poor. At times SSH, top, and other features or commands are very slow to respond, taking several seconds or more. A query that normally takes 5 minutes can sometimes take 30 ...
1
vote
1answer
449 views

How do I keep mdadm from renaming my RAID array upon reboot?

So I have a system (a large instance running ubuntu-11.10 on Amazon EC2) where I've done something like mdadm --create bigdata --level 0 --raid-devices=2 /dev/xvdb /dev/xvdc I get a RAID device ...
2
votes
1answer
629 views

What was the default chunk size in previous versions of mdadm? Is there a way to set data/super offset? Trying to recreate a raid 5 md with all spares

I have a 6 device raid 5 array which had 1 disk go bad and then due to a power outage, the machine shutdown and when it started all the disks were showing up as spares with the following mdadm -E ...
2
votes
1answer
943 views

Can I move an entire software RAID1 array containing Linux to another machine?

I want to move an entire array of drives from old server hardware to new server hardware. There are 3 SATA drives with two partitions each; a small boot partition and a data partition. There are two ...
1
vote
4answers
99 views

Building a raid with 6 hdds which can handle 2 fails

I had a massive data lost with my last raid5 (with 1 spare out of 4 hdds) using mdadm, because 2 drives failed within 1 day (unfortunately). Now I bought new hdds and now have a total of 6 hdds. I ...
0
votes
1answer
1k views

md2_raid1 takes HDD IO up to 99 %

Iotop tool reports that md2_raid1 takes HDD IO up to 99 %. The server's HDD becomes busy and it's impossible to do any operation on it. Here is the output of cat /proc/mdstat: Personalities : ...
9
votes
2answers
2k views

Linux mdadm software RAID 6 - does it support bit corruption recovery?

Wikipedia says "RAID 2 is the only standard RAID level, other than some implementations of RAID 6, which can automatically recover accurate data from single-bit corruption in data." Does anyone know ...
0
votes
1answer
445 views

Move OS from Software RAID (PERC S300) to Hardware RAID (PERC H700/H800)

A client of ours has a server running Windows that is installed on a PERC S300 software RAID. We want to upgrade this to a larger capacity, so we are also upgrading to a hardware RAID card (PERC ...
0
votes
1answer
540 views

Which HDD I can replace WDC WD20EARS with in the software RAID?

I have one customer's server with WDC WD20EARS drivers in a software RAID. These disks are of advanced format (4Kb sectors, not 512 bytes). They are configured as follows: Configuration: ...
1
vote
0answers
1k views

Best way to change disks with Intel Rapid Storage Technology 10.8.0.1068; only one disk in current array

I have a raid 1 array which is currently missing one disk. I want to change the system over to two completely new disks. I currently have Intel Rapid Storage Technology 10.8.0.1068 installed. What is ...
1
vote
1answer
431 views

Upgrading Intel Matrix Storage Manager to Intel Rapid Storage Technology, windows 2003

I would like to upgrade the Intel Matrix Storage Manager software on a windows 2003 std box to the latest version of Intel Rapid Storage Technology which my mobo (ASUS P6X58D-E) supports. Can someone ...
0
votes
1answer
810 views

Intel Matrix Storage Manager RAID rebuild cycles over and over

I am working on a machine that has Intel Matrix Storage Manager on it. It says it needs to rebuild the RAID1 array, but it seems to get to about 35% and then starts the rebuild over again at 0%. ...
2
votes
1answer
917 views

why does windows 2008 resync software RAID after a power outage?

i had a power outage. before the outage my RAID 5 (4 SATA drives) was fully synced. perhaps I was doing some trivial writes during the poweroutage, but afterwards windows decided it has to do a ...
2
votes
3answers
2k views

What would happen if I did a raid on a SSD and an HDD?

I am building another server (cheap) and would like to go with a 256GB SSD drive for my boot and data. This will be enough for my needs, but just having one SSD scares me for a couple of reasons. If ...
2
votes
3answers
1k views

Can I convert a raid10 array to raid0?

I have created a raid10 array using mdadm. Metadata version is 1.2. I want to convert this to a raid0 array, is it possible? P.S. I am having terabytes of data, I want to avoid copying the data over. ...
5
votes
1answer
421 views

What is the meaning of the 'Personalities' feature under /proc/mdstat

On some systems I see this : Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath] [faulty] md1 : active raid1 sdb1[1] sda1[0] 10485696 blocks [2/2] [UU] md2 : ...
0
votes
1answer
136 views

Raid 1 / Raid 10 - Disk Failure

I have setup Software Raid 1 and Raid 10 using VirtualBox for testing purpose. The partition and raid setup look like this: When I deliberately remove Disk2 and restart a server, it booted to OS ...
7
votes
1answer
1k views

Raid 1/10: Kernel panic- not syncing: attempted to kill init

I have setup Raid 1 & Raid 10 in Virtual Box for learning purpose. The following Partitions for 4 Hard Drives: I make a 100mb partition (/boot) on four drives and make that a raid 1 partition. ...
4
votes
2answers
648 views

Software Raid 10 on VirtualBox?

I want to learn how to use Software Raid 10, is it possible to use VirtualBox by adding four storage images? This is my plan: 4x 100mb partitions (1 on each drive) configured as a raid 1 for ...
2
votes
0answers
334 views

MD Raid can't be assembled

I was running a Raid5 with 3 disks at on my homeserver. But had some problems with the back-plane for the disks. The disks weren't detected reliable. So I replaced the back plane and the disks are now ...
2
votes
2answers
2k views

Cant boot newly created mdadm software raid in Debian linux squeeze

Hello I have very strange problem creating swraid on Debian Squeeze Linux. I started creating RAID1 from existing standard instalation of Debian on single drive. So I bought new drive and started ...
4
votes
1answer
830 views

does the *physical* order/location of drives in a mdadm-managed RAID-10 array matter?

i've setup a 4-drive RAID-10 array using mdadm-managed, software-raid on an x86_64 box. it'd up & running and works as expected, cat /proc/mdstat md127 : active raid10 sdc2[2] sdd2[3] ...
2
votes
2answers
9k views

How to setup fake raid for vmware virtual machines?

I have a vmware esxi 5 running on a server with ssd and two hard drives. The server comes with software lsi megaraid and intel rapid storage raid. Neither of them work with esxi. I need to somehow ...
1
vote
1answer
2k views

Convert to dynamic disk / option disabled

I'm trying to setup a software RAID-1 at a new hosted server. It has two 3TB disks in and I've installed a fresh copy of Windows Server 2008 R2 Web Edition with SP1 on one of those disks. A ...