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Questions tagged [raid6]

RAID6 is a method of configuring fault-tolerant hard drive storage. It is similar to RAID5, but differs in that it writes two sets of parity information, thus can survive the simultaneous failure of two hard drives.

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RAID 6 - any write amplification in 4-drive RAID?

We're planning to move from a 4-drive RAID6 to a SSD RAID 1, and I was analyzing smartctl data to see how many GB we've writen to the drives over the past year so I can estimate the lifetime of the SSDs based on their endurance rating. I'm thinking…
sa289
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Raid 6 with HP P421?

I cant figure out if I need to buy a licens key to enable Raid 6 for this raid controller? I can't find where to buy one and I find pages where it says that its now free. sudo hpssacli ctrl slot=1 show detail gives me: Smart Array P421 in Slot 1 Bus…
user1506602
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Repairing RAID6 with two drive issues mdadm

I have had two disk failures on my RAID6 array. I have added two new disks and did the following: I ran mdadm /dev/md1 --remove on the two disks I set up my RAID on the 1st partition of each disk (for alignment reasons). As the replacement disks…
user3526827
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Linux soft RAID6 how to identify last failing drive

I have a RAID6 array that had been neglected, and just had the third drive fail. I want to do a ddrescue of the last drive to fail to try to recover the RAID, however I don't know how to identify which drive that was. To make matters worse, I'm…
John P
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Running RAID 6 with a smaller drive

It looks like one of my hard drives failed in our RAID 6 (4 x 2TB) configuration. Unfortunately, I only have immediate access to a 1TB drive. Would there be an issue with temporarily replacing the 2TB with a 1TB drive? At this time, we are consuming…
Sean
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First 500MB of RAID6 array is wiped, how to recover?

We have a RAID6 array with 12 disks on a 3ware 9650SE-12ML controller. An engineer of our server provider issued this command by mistake: sudo dd if=/dev/zero of=/dev/sde bs=1M count=500; sync; /dev/sde is the linux device of the raid array. This…
refik
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recovering a corrupt degraded btrfs RAID6, need to manually clear an inode

I have a btrfs RAID 6. I have lousy hard drives, one failed, and another failed during recovery. Now I am without parity and cannot rebuild--a third drive is throwing read errors on a few sectors. Since I can't remove it, I overwrote the bad…
Jacob Stoner
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RAID6 Ubuntu rebuild - how to calculate best parameters for fastest rebuild

I am doing a resync on a RAID6 array and I am looking at some 2 days to complete. I looked here for hints on how to speed it up, but I have, instead, managed to slow it down! HW details are: 10x 4TB WD Black HDDs (one died so resync is due to this)…
MarcusL
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Need help recovering RAID 6 array

My CentOS 6.5 server had its primary drive fail the other day. Our hosting company replaced the primary drive and reinstalled the OS. The system is up and running, but the 15TB of RAID6 storage isn't mounting. I need help figuring out how to get it…
Jerry Palmer
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Which Inode Size for Files bigger than 60mb

I will create a new server and wondered about the I-node options default, news, large file and largefile4. I searched the net and found explanations about 256kb until 4mb for one I-node, but i cant conclude the average file size for one of this. I…
Sunghost
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mdadm raid6 array reports incorrect size in df -h after grow

I've recently grown a 5x 3tb mdadm raid6 array (8tb) with a sixth disc in fedora 18, and after full rebuild and check, "mdadm --detail /dev/md127" returns the below: Version : 1.2 Creation Time : Sun Feb 10 22:01:32 2013 Raid Level :…
Faufnir
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Safest approach when designing storage server

We are planing cloud solution for our customers and we are really concerned with designing safest storage servers for their files. This storage won't be IO demanding, as it will contain only files which are uploaded by users. Databases will be…
Goran Radulovic
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Online expansion PERC700 RAID6 server

I have a Dell PowerEdge r510, with 5 HDDs in a RAID6 configuration. I'd like to add a 6th disk (and, in the future, more) to grow the hardware RAID configuration. I have a logical volume, in which the current disks are all physical volumes. I…
radpotato
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Using 2-port LSI 9286-8e card to control 24 SAS HDDs

I would like to rely on a RAID-on-chip solution to control 24 SAS hard drives in a direct-attached environment. How would you approach this to get best bandwidth given that I'd like to spend less than $10,000 on the interconnect. I've read that LSI…
GregC
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Linux software RAID6: 3 drives offline - how to force online?

This is similar to 3 drives fell out of Raid6 mdadm - rebuilding? except that it is not due to a failing cable. Instead the 3rd drive fell offline during rebuild of another drive. The drive failed with: kernel: end_request: I/O error, dev sdc,…
Ole Tange
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