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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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Windows software raid drives deactivated

Not sure what to make of this behaviour, but here goes. I have 3 Seagate 4 T drives in a windows 2012 r2 server in a software raid 5. Recently, I logged onto the server to see that 2 disks (specifically the disks in sata slot 1 and 2) were…
Stephan
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Need Help Restoring A Failed RAID5

I was handed a Seagate NAS with 4 HDDs set up as RAID5. One of the drives failed: won't spin up, clicks, etc. The other 3 drives are fine. They spin up, when connected via USB, the data on them is clearly visible with a hex viewer. Seagate has…
Marc
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Raid Status - Online vs Ready vs Foreign

What does Raid state Online, Ready or Foreign means? What other state can it be? What needs to be done in such state? I think Online is the only safe state. What are the DO's and Don't during clearing its state or replacing drives (or when should we…
user630702
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What a benefit of RAID 1,5,10 vs every night simple diff backup

Given: 2 HDD in RAID and case when we lose 1 of them after 3 years: If we use RAID 0, we lost data If we use RAID 1, we have a copy on possible also bad-health disk, any restore may cause failure also If we use RAID 5, same as RAID 1, but we can…
alexloiko
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Server won't boot after adding two new disks

I have an HP ML350 G6 server with 3 600Gb SAS drives on RAID5. I added 2 new 1Tb disks and configured a new Array with RAID1. Al of a sudden I got the blue screen of death, the server rebooted and now I get operating system not found. I've run the…
MikeT
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HP Proliant DL360p gen8 Unrecoverable Media Error. Amber lights on 3 disks

I have HP Proliant DL360p gen8. 4 disk on RAID 5, 3 of them have amber light on them. I did chkdsk on my virtual machines none reported any error. Am i able to fix it without buying and replacing disks? If no then do i need to replace all 3…
Igor Sikora
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Recovering formatted Microsoft Storage Space Raid-5

I have accidentally formatted my Storage Space. The setup is 3 units of USB 3.0 Hard drives with 4TB each. Total 7.4Tb of storage available. I have used Active File Recovery with no success.It finds my files and directories. But the recovered files…
Amir Rezaei
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How to diagnose/fix slow file management on Windows Server 2012?

The setup is: FUJITSU PRIMERGY TX300 S7 RAID Ctrl SAS 6g 5/6 512mb (d2616) Windows Server 2012 64 bit Volume C: RAID 1 (2 HDDs) Volume D: RAID 5 (8 HDDs) The problem is: When we do something with a large amount of files on volume D:,…
real_sm
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Recover files from one of three mdadm RAID5 disks

I have lost 2 of 3 mdadm RAID5 disks. How can i recover whatever files are available on the remaining one disk? Sundeep
Sundeep Goel
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Install Windows Server 2012 on separate disk or in RAID 5?

I have a RAID controller with 4 1TB disks and first I put them all in a RAID 5 array, partitioned 1TB for OS and 2TB for data. Then I noticed that the raid array was never idle. It was constantly writing 24/7 and I figured it must be the swap…
Max Kielland
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Raid Drive Upgrades

I have a RAID 5 setup with 5 2TB drives. If I start to replace the 2TB with 4TB, once I have enough, can the Array be moved to 4TB's? I know that if I put a 4TB in a 2TB Raid, the 4TB will recognize 2TB for the RAID.
Bill Fry
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mdadm --grow power failure, /dev/md2 no longer detected, RAID5

Did a terrible stupid mistake. Please advise me how should I best proceed. My configuration is a RAID5 of 4x4TB drives. On top of it, LVM with various partitions including /, swap, everything. The configuration was quite automatic based on…
bigfailure
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Which raid array will be best practices with seven 1.2 tb hdd system

I have a server which have seven 1.2 tb hard disks. I have to create raid array but i don't decide which raid i use? First of all, first and most important matter is security. At any cost i must not to lose data. So, i think raid 6 and one hot…
cem
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Degraded md RAID5 won't boot

I'm running a Ubuntu server on a md RAID5. I started to have some issue with one disk, I received the following email from mdadm: A DegradedArray event had been detected on md device /dev/md/0. md0 : active raid5 sdb2[1](F) sdd2[2] sda2[0] …
Xantra
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Is it possible to recover a RAID 5 in this case?

Is it possible to recover a RAID 5? After losing the "/proc/mdstat" and run by mistake "mdadm --create --verbose /dev/md0 --level=5 --raid-devices=4 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1" instead of mdadm --assemble --scan.
juan
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