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 ...

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4answers
13k 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 ...
21
votes
10answers
62k views

Which is better: RAID5 + 1 Hotspare / RAID6?

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?
16
votes
7answers
6k 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 ...
13
votes
7answers
12k 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
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
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3answers
2k 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 ...
10
votes
9answers
16k 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 ...
10
votes
2answers
789 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
1k 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
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 ...
9
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
2answers
2k 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 ...
6
votes
3answers
25k 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 ...
6
votes
2answers
5k 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 ...
6
votes
4answers
458 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
1answer
591 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
7answers
9k 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
4answers
3k 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, ...
5
votes
3answers
4k 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
4answers
9k 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
3k 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 ...
5
votes
1answer
1k 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
960 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 ...
5
votes
2answers
4k 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
3k 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
3answers
1k 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 ...
4
votes
5answers
2k 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
242 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
2answers
332 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
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
3answers
1k 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 ...
4
votes
2answers
401 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. ...
4
votes
0answers
37 views

Is it safe to stop a RAID 5 expansion? [migrated]

I'm having some issues expanding a RAID 5 array on a Synology DS413. The drive has gone from 3 x 3TB WD Green drives to 4 x 3TB. I started an expansion operation and it's been stuck at about 60% and ...
3
votes
8answers
942 views

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

Which is more standard in large enterprises: RAID5 or RAID10?
3
votes
6answers
822 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
995 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
1k 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
3answers
3k 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 ...
3
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 ...
3
votes
2answers
4k 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 ...
3
votes
2answers
139 views

Drive configuration for 5 large databases

I've got 5 databases, each 300GB, currently on a RAID 5 array consisting of 5 drives. All the databases are used heavily, at the same time, so drive speed is an issue. Would I see better performance ...
3
votes
4answers
1k views

Optimizing RAID 5 for BackupPC use (small random reads)

I am running a BackupPC server with a hardware RAID 5 for the main storage of the backups. Since the machine was created on a tiny budget, the controller is a 3Ware 9500S-4LP for the PCI port and the ...
3
votes
2answers
638 views

Replacing a Hard Disk in RAID 5 Array with Newer Version

Recently, 1 out 4 disks in my RAID 5 array failed. I searched for a replacement part and learned that only a newer version of the hard disk is available. This "newer" version has the exact same specs ...
3
votes
4answers
1k views

MediaShield RAID 5 is showing up as 760GB when the actual size is 2.7TB

I just finished setting up Windows 2003 Server on my new server, and I started setting up a RAID 5 for it. I have 4x1TB Hard Drives. From MediaSheild RAID Utility (at boot time) the RAID size is ...
3
votes
1answer
105 views

how to determine which drive belongs to which slot on raid 5

i have an HP DL380 G8 machine with 4 hard drives of same size and running on raid 5. unfortunately during a service process of our data center one of the junior team members pulled out all four hard ...
3
votes
2answers
2k views

Raid 5 with 4 disks on Debian automatically creates a spare drive

I'm trying to to create a RAID 5 with 4x 2TB disks on Debian 6. I followed the instructions from: http://zackreed.me/articles/38-software-raid-5-in-debian-with-mdadm I created the raid with following ...
3
votes
1answer
4k views

RAID5 on SmartArray P410i online resize

I have P410i+256M Cache without battery backup. My RAID5 was build over 3*136GB disks, now all disks were replaced to a 3*300GB array. How can I extend it to use the whole space? HPacucli doesn't ...
3
votes
1answer
868 views

Growing a RAID5 using mdadm with multiple drives?

I have a RAID5 array that consists of 3, 2TB drives. I want to add 2 more drives. The tutorials involve adding a single drive to an array, such as this: https://raid.wiki.kernel.org/index.php/Growing ...
3
votes
6answers
4k views

Recover RAID-5 that was already running in degraded mode (lost a second disk)

this is silly, this has happened before and I figured out how to fix it and it was fine. I'm running 4 500GB SATA drives in a RAID-5 on Ubuntu 7.10 server. One of the disks failed (actually I think ...