RAID solution handled by the operating system.

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42
votes
10answers
6k views

RAID - software vs. hardware

I have always used hardware based raid because it (IMHO) it's on the right level (feel free to dispute this) and that OS failures are more common to me than hardware issues. Thus if the OS fails the ...
5
votes
3answers
6k views

mkfs Operation Takes Very Long on Linux Software Raid 5

I've set-up a Linux software raid level 5 consisting of 4 * 2 TB disks. The disk array was created with a 64k stripe size and no other configuration parameters. After the initial rebuild I tried to ...
4
votes
3answers
6k views

explain md's raid10,f2

I know how most of the various RAID's work. But I stumbled on the recommended raid10,f2 mode while researching linux software raid. I don't really understand how it works on 2 or 3 disks. could ...
19
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 ...
10
votes
5answers
9k views

How do you monitor the health of a mirrored disk in Windows?

I have a Mirrored Dynamic disk on my Windows 2003 Server. How do you monitor the health of the volume? Is there a way to have the server send an email when there is an issue with the volume? Is there ...
5
votes
1answer
1k views

Encrypted LVM on RAID1 - Failure testing, manual mount

We have an Ubuntu 10.04 LTS server set up with LVM running on top of disk encryption, which runs on top of a RAID1 volume comprised of two physical SATA disks. The configuration looks like this: ...
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 ...
2
votes
2answers
851 views

Linux RAID 1: How to make a secondary HD boot?

I have the following RAID 1 on a Centos 6.5 server: # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb1[3] 974713720 blocks super 1.0 [2/1] [_U] bitmap: 7/8 pages [28KB], ...
13
votes
4answers
10k views

Best way to grow Linux software RAID 1 to RAID 10

mdadm does not seem to support growing an array from level 1 to level 10. I have two disks in RAID 1. I want to add two new disks and convert the array to a four disk RAID 10 array. My current ...
10
votes
2answers
13k views

How do I move a Linux software RAID to a new machine?

I have a newly built machine with a fresh Gentoo Linux install and a software RAID 5 array from another machine (4 IDE disks connected to off-board PCI controllers). I've successfully moved the ...
7
votes
6answers
42k views

How to view status of software RAID 1 resynching?

I have two 500 GB disks and yesterday I mirrored first drive to the second one using software RAID 1. PC has now been on for 30 hours. Both disks say "Resynching", but there is no progress indicator. ...
5
votes
1answer
9k 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 ...
6
votes
1answer
7k views

Boot from software RAID 1 on Windows Server 2008 R2

I have a Windows Server 2008 R2 x64 system with a single hard drive, and I have a spare hard drive of same size/model that's not being used. I was thinking about dropping in the new drive and setting ...
1
vote
1answer
70 views

Disabling damaged RAID 1 to read from healthy HDD

One of the HDDs in my software RAID 1 on a dedicated server is damaged. The customer support is slow to respond. I would like to transfer all data I need to another server, but file access is ...
2
votes
2answers
114 views

mkfs on raw software raid device or partition

I am making a huge RAID10 device (8 TB) for storage on CentOS. I have created the 4 partitions on my 4 physical hard disks and have created the raid device /dev/md2 out of those 4 partitions. Now ...
1
vote
1answer
218 views

Linux RAID1, with reads restricted to one disk

I'm looking for a way to replicate a all changes on a filesystem between two disks in a master->slave setup. One of the disks is much faster for reads, so I would like to direct all reads to this ...
0
votes
1answer
248 views

Raid array Devices are not removed

cat /proc/mdstat Personalities : [raid1] [raid0] [raid6] [raid5] [raid4] [linear] [raid10] md11 : active raid10 sde1[3] sdj1[4](F) 286743936 blocks 64K chunks 2 near-copies [4/1] [___U] ...
0
votes
4answers
6k views

Expand Windows Server 2008 RAID 5 array

I have a Windows 2008 Standard server. It currently has 3x 1TB drives in Software RAID 5 (as per the Disk Management Console). I need to add another 2x 1TB drives. Is there any way to add these two ...
10
votes
1answer
6k views

Easy to expand Linux software RAID 5 with XFS. Best practices?

I use my Ubuntu machine as a file server for Windows/Linux/Mac clients using a Samba share. I need it to be easily expandable by just adding more hard drives without having to move any data back and ...
12
votes
11answers
2k views

Is RAID5 more robust than RAID1

I am about to replace an old hardware RAID5 array with a Linux software RAID1 array. I was talking to a friend and he claimed that RAID5 was more robust than RAID1. His claim was that with RAID5, on ...
8
votes
5answers
3k views

Boot Debian while RAID array is degraded

Recently, I came across Ubuntu Server install. During install, it asked me whether or not to allow booting system from degraded RAID array (probably because I installed system onto RAID1 /dev/md0 ...
8
votes
5answers
4k views

Software vs. Hardware RAID1 (Mirror)

How does the Software Mirror in Windows Server systems compare to an affordable hardware/BIOS RAID? I've had some rather bad experiences with onboard hardware RAID controllers, so I would want to ...
4
votes
2answers
4k views

Where should my swap partition/s live when using software RAID1? Performance? LVM?

When I search around for example RAID1 installations, it seems that admins tend to place their swap partition under RAID1. To me, it is more intuitive to have two disks, each with a large partition ...
8
votes
3answers
4k 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 ...
8
votes
3answers
6k views

LVM volume group shared between KVM/libvirt host and guests: is this a bad idea?

I have just built a shiny new KVM/libvirt-based virtual machine host, containing 4 SATA II hard drives, and running CentOS 5.5 x86_64. I have decided to create virtual machine disks as logical ...
6
votes
4answers
12k views

How to create a software raid5 array without a spare

I am trying to create a software raid5 array using mdadm: $ linux # mdadm --create --verbose /dev/md0 --level=5 --raid-devices=4 --spare-devices=0 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 mdadm: ...
6
votes
1answer
751 views

Linux fails to reassemble RAID array after disk upgrade

I have an Ubuntu (9.10) machine with 4 SATA disks. Each disk is partitioned identically, with the first few gigabytes set aside for a RAID 1 array (/dev/md0) for the boot volume, and the ...
5
votes
2answers
2k views

How to know which disk has failed on a Mirrored Raid? marked as DR0

Our 2ndry DC, which is on a W2K8R2 Mirrored software raid has lost it's sync, and disk management displays the failed redundancy error How do I know which of the disks has failed? (beside to try ...
4
votes
1answer
374 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 ...
3
votes
2answers
4k views

How can I view Server 2008 Software RAID 5 Resync Progress?

Skipping over the pros/cons of RAID 5, I have a software RAID-5 array made from 3x 2TB disks. I started the sync and nearly 12 hours later the sync is still going. Is there any way that I can view the ...
3
votes
2answers
165 views

How to know which Sata Channel my dev/sd* associated with

Just in case for me (and others) when a software raid 5 degraded, how do I know which Sata Channel my dev/sda, /dev/sdb, etc. associated with, so that we can replace them properly?
3
votes
3answers
8k views

Windows Server software RAID volume constant “Failed Redundancy”

I'm using Windows Server 2008 software RAID volumes. So, recently I've started to receive error in System event log: "The device, \Device\Harddisk7\DR7, has a bad block." Meanwhile volume in Disk ...
2
votes
0answers
2k views

How to recover an mdadm array on Synology NAS with drive in “E” state?

Synology has a customized version the md driver and mdadm toolsets that adds a 'DriveError' flag to the rdev->flags structure in the kernel. Net effect - if you are unfortunate enough to get a array ...
1
vote
1answer
662 views

How to boot after RAID failure (software RAID)?

Previously I had a software raid set up using (mdadm) of drives sda and sdb. sdb failed and the only way to reboot the system was by unplugging the second hard drive. Now I've added fresh sdb and sdc ...
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: ...
1
vote
3answers
2k views

Creating a partitioned raid1 array for booting a debian squeeze system

I'd like to have the following raid1 (mirror) setup: /dev/md0 consists of /dev/sda and /dev/sdb I created this raid1 device using mdadm --create --verbose /dev/md0 --auto=yes --level=1 ...
1
vote
1answer
3k views

Unable to access resume device in CentOS

I moved my CentOS soft-RAID1 drives to another box, and now it fails to boot. When I launched the boot process from the grub menu, I get the following error: "Unable to access resume device ...
6
votes
1answer
595 views

Should I worry about the integrity of my linux software RAID5 after a crash or kernel panic?

I have a dual core Intel i5 Ubuntu Server 10.04 LTS system running kernel 2.6.32-22-server #33-Ubuntu SMP with three 1TB SATA hard drives set up in a RAID5 array using linux md devices. I have read ...
5
votes
1answer
2k views

High I/O latency with software RAID, LUKS encrypted and LVM partitioned KVM setup

I found out a performance problems with a Mumble server, which I described in a previous question are caused by an I/O latency problem of unknown origin. As I have no idea what is causing this and how ...
4
votes
3answers
2k views

How do I stop and repair a RAID 5 array that has failed and has I/O pending?

The short version: I have a failed RAID 5 array which has a bunch of processes hung waiting on I/O operations on it; how can I recover from this? The long version: Yesterday I noticed Samba access ...
3
votes
1answer
104 views

ZRAID1 pool size bigger than expected

I have 3x 4TB drives for a ZRAID1 config (single parity drive) After running zpool create data zraid1 sdb sdc sdd I have a volume that's 10.9T in size, which is what I would expect from a stripe ...
3
votes
1answer
1k views

Removing a device in “removed” state from Linux software RAID array

My workstation has two disks(/dev/sd[ab]), both with similar partitioning. /dev/sdb failed, and cat /proc/mdstat stopped showing the second sdb partition. I ran mdadm --fail and mdadm --remove for ...
3
votes
2answers
3k views

Can't boot after Disk 0 of software raid is replaced

On a windows 2008 R2, which was on a mirrored software raid, Disk 0 has failed. After I replaced it with an alternate drive (can not find the same capacity and model) - the server isn't booting. ...
2
votes
2answers
482 views

Remake SW RAID1 from a new HDD and an old HDD with bad blocks

I have a SW RAID1 and I just replaced /dev/sda with a new HDD as the old one failed. Now, upon trying to recreate the RAID array I discovered that the "good" HDD (/dev/sdb) has bad blocks with prevent ...
2
votes
4answers
175 views

Setup a Backup for 90k+ photos and desktop file structure

I'm working for an engineer that takes about 500 pictures a month and uses Adobe Lightroom to manage them. He currently has about 2TBs of data that need to be backed up regularly. To setup a backup ...
2
votes
6answers
1k views

Raid1 question

Let's say I have a software raid1 array from two partitions. I get one HDD out of the computer, and put it into another computer, and copy some data to the mirrored partiton. What happens when I put ...
1
vote
1answer
158 views

How to display/define Mirror/Stripping pairs with mdadm

I want to make a standard linux software Raid10 over 4 HDD. The server has 4HDDs, 2 pairs from different vendors in order to avoid batch problems. I want to have the mirror over two different ...
1
vote
2answers
1k views

Is 5MB/s a reasonable speed for Dell Software Raid Controller in Raid5

I have a new PowerEdge T320. Details are: Intel Xeon E5-1410 @ 2.8 GHz 16GB Windows Server 2008 r2 configured as Domain Controller Dell PERC S110 Software Raid 4x 7200 rpm 1TB drives configured in ...
1
vote
2answers
7k views

mdadm rebooted, array missing? can't assemble?

Not sure what is going on with my Array. I rebooted ubuntu 12.04.1 and got a error on startup that fstab couldn't mount the filesystem UUID I have for my mdadm array. After running a few commands a I ...
1
vote
1answer
681 views

What parameters to mdadm, to re-create md device with payload starting at 0x22000 position on backing storage?

I try to recover from mdadm raid disaster, which happened when moving from ubuntu server 10.04 to 12.04. I know the correct order of devices from dmesg log, but given this information, I still cannot ...