RAID (redundant array of independent disks, originally redundant array of inexpensive disks[1][2]) is a storage technology that combines multiple disk drive components into a logical unit. Data is distributed across the drives in one of several ways called "RAID levels", depending on what level of ...

learn more… | top users | synonyms

36
votes
10answers
101k views

Which is better: RAID5 + 1 Hotspare / RAID6? [closed]

Just curious, I have 6 x 1TB 7200RPM Near Line SAS for my new server. I can either configure it as RAID5+1 Hot Spare or RAID6. What should I choose?
34
votes
5answers
17k views

Recover RAID 5 data after created new array instead of re-using

Folks please help - I am a newb with a major headache at hand (perfect storm situation). I have a 3 1tb hdd on my ubuntu 11.04 configured as software raid 5. The data had been copied weekly onto ...
20
votes
8answers
35k views

RAID-5: Two disks failed simultaneously?

We have a Dell PowerEdge T410 server running CentOS, with a RAID-5 array containing 5 Seagate Barracuda 3 TB SATA disks. Yesterday the system crashed (I don't know how exactly and I don't have any ...
15
votes
3answers
6k views

mdadm raid5 recover double disk failure - with a twist (drive order)

Let me acknowledge first off that I have made mistakes, and that I have a backup for most but not all of the data on this RAID. I still have hope of recovering the rest of the data. I don't have the ...
13
votes
6answers
17k views

How to recover from a drive failure in a RAID 5 configuration?

This morning a drive failed on our database server. The drive array (3 disks) is setup in a RAID 5 configuration. While we wait for a drive replacement we are preparing for a recovery strategy. Users ...
12
votes
9answers
31k views

How many disks is too many in this RAID 5 configuration?

HP 2012i SAN, 7 disks in RAID 5 with 1 hot spare, took several days to expand the volume from 5 to 7 300GB SAS drives. Looking for suggestions about when and how I would determine that having 2 ...
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 ...
12
votes
2answers
19k 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 ...
11
votes
2answers
2k views

What counts as a 'large' raid 5 array?

A recent issue with a Buffalo TeraStation NAS here in my office has got me investigating Raid 5. I've found a few different articles talking about the unsuitability of using raid 5 in large arrays, ...
10
votes
3answers
4k views

Recover from a Punctured RAID array

here is my situation. I have a Dell Server with a Dell Perc 7i controller, (LSI Controller). I had a drive give me an Failure Predicted warning so I called their support and they came out and ...
10
votes
2answers
4k views

Convert linux software raid from raid5 to raid6

I currently have a file server with 3 1.5TB disks in a RAID5 array. Since it's pretty much full, I got three additional disks (also 1.5TB each). Now I'd like to switch to RAID6 since 6TB space is ...
10
votes
1answer
7k 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 ...
8
votes
2answers
1k views

Windows Server Backup Error - Volumes Larger than 16.7TB cannot be protected?

I'm trying to use Windows Server Backup to backup a RAID array on my new server. But, when I do, I run into this error: The server is running Windows Server 2012 R2 and the array in question is ...
7
votes
3answers
21k views

What are the main points to avoid RAID5 with SSD?

My understanding is that an SSD has a limited amount of writes. RAID5 performs many writes due to parity information across the drives. So reasoning states that RAID5 would kill and lower the ...
7
votes
3answers
39k views

RAID 10 or RAID 5 for multiple VMs - what is the best choice?

I have just ordered a new rig for my business. We do a lot of software development for Microsoft SharePoint and need the rig to run several virtual machines for development and test purposes. We will ...
7
votes
3answers
7k views

Is it safe to transfer RAID 5 disks from one server to another?

I have (what I assume) will be a relatively simple question. I have an old file server that I've decommissioned and replaced. I would like to re-use the hardware from the old file server at our ...
6
votes
4answers
13k views

How do I configure RAID 5, especially stripe size, with 24 x 1.2 TB drives for CentOS 6?

For a Dell R920 with 24 x 1.2TB disks (and 1TB RAM), I'm looking to set up a RAID 5 configuration for fast IO. The server will be used to host KVM VMs that will be reading/writing files of all sizes, ...
6
votes
2answers
10k views

Convert a Smart Array RAID5 array to a RAID6 (ADG) variant

I have an HP MicroServer (N36L) with a SmartArray P410 controller, a 512MB BBWC unit and four (4) 2TB disks connected. Three of those disks are configured as a single RAID5 array and one is left alone....
6
votes
4answers
486 views

mdadm: Replacing array with entirely new drives

I have a server with three 500GB drives, with most of my data in a RAID5 configuration spanning the three of them. I just purchased and installed four 1TB drives, and the intention is to move off of ...
6
votes
2answers
2k views

Reusing Raid 5 Drive?

We have two servers (ML530 G2 and DL380G2) w/ identical HP 10K RPM SCSI drives w/ a raid 5. One is decommissioned and the other will be decommissioned shortly. However, one of the drives on the ...
6
votes
1answer
724 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 ...
6
votes
2answers
203 views

How to get Newly Expanded RAID to show correct size in Debian

I recently expanded my RAID 5 Storage Virtual Drive from 6TB to 9TB. The Dell OMSA and the bios for the RAID controller both show I'm at 8382GB. Which is fine. But when get into Debian and poke ...
6
votes
1answer
5k views

Is it safe to shutdown a machine while rebuilding/recovering/growing a RAID5 array that was built with mdadm

I have recently started a recovery on my 5-drive RAID in my file-server, and it says it'll take 691+ minutes to complete. I was wondering what would happen to the process if the machine lost power - ...
5
votes
7answers
10k views

Raid 5 with hot spare or RAID 10 with no hot spare?

Yes, this is on of those "do my job for me" questions, have some pity:) I'm at the limit for what I can do with the number of hard drives in a server without spending a substantial amount of money. ...
5
votes
5answers
24k views

Replacing a dead hard drive in RAID 5 with a different type

One of the drives failed in my server configured with RAID 5, and I can't find a exact replacement. From my understanding, RAID 5 supports drives with different sizes. Is this safe? Any ...
5
votes
2answers
6k views

RAID 5 with big SATA disks. Do or don't?

Is it sane to build a machine with RAID 5 expecting to hold around 5 Tb (and able to grow) with 1.5 or 2 Tb SATA II disks? It will be used as audio and documents storage. I already have chosen a ...
5
votes
3answers
998 views

ZFS, raidz1: Why is the volume size (42T) so much smaller than the pool size (50T)?

I have a pool of 28 2TB-disks (56T) in 4 arrays of 7 disks. Since it's raidz1 (~RAID5), I'd expect 1 disk to be used for parity in each array, so the resulting volume should be 2TB*4*(7-1)=48TB, right?...
5
votes
4answers
10k views

How to grow a hardware Raid 5?

I have a Dell PowerEdge 2970. Currently it runs as a ESXi server with a handful of VM's on it. I have 3 300GB drives plugged in to it, and 5 open trays across the front. It is setup as a hardware ...
5
votes
3answers
2k views

Which RAID level (5 or 0+1) should I use with 3 disks and why?

This is specifically for backup storage but, for informational purposes, I would like to know why would you chose one over the other? Five minutes ago, I was not even aware that RAID 0+1 was an ...
5
votes
1answer
2k views

Why do I get a DegradedArray event with mdadm

Just so we're clear on what's happening: I bought 4 new sata 2 drives, with the intent of using them in a raid5 all drive are fully recognised by both my bios and my linux box (gentoo) I created a ...
5
votes
2answers
5k views

Ext4 superblock corrupted after successful(?) mdadm grow and resize2fs

Some system details AMD Phenom II X6 1090T, 16GB DDR3 1600 running 11.04 natty, 2.6.38-8-server Raid in question consists of 5 SATA drives; 4 Samsung, 1 Western Digital; 500 GB each Drives are ...
5
votes
1answer
660 views

RAID-5 or RAID-6 - is RAID-5 really that bad? [duplicate]

Possible Duplicate: Which is better: RAID5 + 1 Hotspare / RAID6? I need to decide myself between RAID5 and RAID6. The servers have a hardware-RAID controller and 6 drives each. The drives ...
5
votes
3answers
2k views

How do I calculate the disk subsystem i/o capacity

I am trying to figure out the number of 8K page i/o capacity for a disk subsystem. The drives are SATA 7200 RPM - 4 drives in a RAID-5 configuration. I am not sure about the SCSI controller but the ...
5
votes
1answer
1k views

Configure Windows RAID-5 “drive failed” timeout?

When a hard-drive controller detects an error, and needs to remap a sector, the drive normally becomes unresponsive for the seconds (or possibly minutes) it takes to try to complete the re-mapping. ...
4
votes
5answers
4k views

How should I sanitize a SAS drive that I removed from a RAID 5 Array?

I had a disk experience a predictive failure. As a result, I removed the drive and replaced it. Now that I have the drive removed, I would like to sanitize it. What is the easiest way to go about ...
4
votes
4answers
331 views

Is it safe to mark a disk ok, in a degraded raid 5 array?

Intel Matrix Storage Console 8.9 showed a degraded array with one disk failure. Yet it offers the option to mark the disk as ok and rebuild the array? When would it be appropriate to do this? Does it ...
4
votes
4answers
3k views

How does RAID detect a faulty HD?

I have been looking over Raid levels over the past 3 days. And have been weighing up the pro/cons of raid controllers hardware/software. I understand that RAID is not a backup solution and I'm ...
4
votes
2answers
700 views

What steps should I take to best attempt to recover a failed software raid5 setup?

My raid has failed, and I'm not sure what the best steps to take are in order to best attempt to recover it. I've got 4 drives in a raid5 configuration. It seems as if one has failed (sde1), but md ...
4
votes
2answers
417 views

Extended raid 5 is not expanding

I have a D2700 with 25 1Tb disks with a P421 raid card in a dl360p gen8 HP server. It was raided as two raid 5 with 2 spare each. I decided to make one raid 5 out of them, deleted one raid and added ...
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 ...
4
votes
2answers
6k 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 ...
4
votes
2answers
517 views

Windows Server 2008 Software Raid 5 - Data integrity issues

I've got a server running Windows Server 2008 R2, with a (windows native) software raid-5 array. The array consists of 7x 1TB Western Digital RE3 and RE4 drives. I have offline backups of this array. ...
3
votes
8answers
980 views

Which is more standard in large enterprises: RAID5 or RAID10?

Which is more standard in large enterprises: RAID5 or RAID10?
3
votes
7answers
24k views

RAID5 2-disk failure - what steps to take?

I've got a 6-disk RAID5 array on a gentoo server. mdadm is reporting that two of the disks have failed. In the event that the disks are actually gone, I'm prepared to send the drives to professionals ...
3
votes
6answers
2k views

Server RAID died. How would you recover data from its drives?

We have 9 machines at the moment. One of them had an electrical fault which fried the board but the drives seem ok. I'm not entirely sure how I would even attempt to recover data from it. The drives ...
3
votes
4answers
2k views

Running swap on RAID10 or RAID5?

In follow-up to this previous question (and it's excellent answer), I am curious to know if running swap on a RAID5 might not be better than on a RAID10. My thinking is that you might lose a bit on ...
3
votes
6answers
2k views

Linux RAID 5 with non identical disks

I want to use a software raid on a Linux server I am creating. I have 2 identical Maxtor 250 GB hard drives and one Western Digital 250GB hard drive. I know I know I can easily set up raid 1 with the ...
3
votes
5answers
2k views

Detecting raid setup in centos 5

We have bougth a server off of Iweb web hosting and its supposed to have raid5 hardware installed. At this point so many things have gone wrong with IWeb we are just not sure we have our raid at all. ...
3
votes
5answers
5k views

How long should a RAID Reconfiguration take? (Adaptec 6805)

I'm experimenting with various RAID configurations of a new Adaptec 6805 (not the 'E' model) Attached are 8x Hitachi 5400RPM 2TB SATA 6Gb Drives using the miniSAS to SATA cables provided. I created ...
3
votes
2answers
7k views

Proliant DL360 Raid5 Hot Swap Drive

I have a DL360 G5 running WinSrvr2003 with a 3 drive (72GB) SAS Raid 5 array on P400i controller. The single array has two partitions. (OS and a data store) Drive 2 has failed and is off line (Amber ...