Questions tagged [raid5]

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 redundancy and performance (via parallel communication) is required. RAID 5 is a specific implementation.

RAID 5 (block-level striping with distributed parity) distributes parity along with the data and requires all drives but one to be present to operate; the array is not destroyed by a single drive failure. Upon drive failure, any subsequent reads can be calculated from the distributed parity such that the drive failure is masked from the end user. However, a single drive failure results in reduced performance of the entire array until the failed drive has been replaced and the associated data rebuilt. Additionally, there is the potentially disastrous RAID 5 write hole. RAID 5 requires at least three disks.

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Source: wikipedia

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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?
Raptor
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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 another separate off the computer hard drive until…
Brigadieren
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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 controllers to the new machine; the drives are detected…
romandas
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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 logs). Upon booting up into the RAID controller…
Mike Furlender
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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 performance of Solid State Drives at a faster rate. The…
Damainman
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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 kind of money to take the drives to a recovery…
Peter Bos
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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 volumes in the SAN, each one with RAID 5, would be…
Tom
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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 are continuing to work on the system, albeit very…
Philip Fourie
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What's the difference between a "degraded" RAID 6 array and a "clean" RAID 5 array?

Suppose you have two RAID arrays, one with N disks and one with N+1 disks. The array with N disks was formatted as a RAID 5 and left alone, while the other array was formatted as a RAID 6 before one of its disks was removed. Now both arrays have N…
ATLief
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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 enough and I'd like to have the increased safety of…
ThiefMaster
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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 forth. This is how I have done it so far. I have…
Taskinen
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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 read the parity data was read to make sure that…
andynormancx
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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, or with large disks Here is one example article…
Rob
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Raid 5 Hard disk corruption

I have got IBM x3650 M4 server. It is configured with Raid 5 & includes 4 SAS hard disk with capacity of 500 GB each. Now the 2 Hard disk are showing as bad. So by replacing the 2 hard drives with new one will the data get rebuild automatically or…
lakhan vasre
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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 20TB in size (with 18TB usable); less than 1TB is…
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