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.
127
questions
97
votes
12
answers
34k
views
How bad is it really to install Linux on one big partition?
We will be running CentOS 7 on our new server. We have 6 x 300GB drives in raid6 internal to the server. (Storage is largely external in the form of a 40TB raid box.) The internal volume comes to ...
- 1,081
47
votes
10
answers
153k
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?
- 1,021
18
votes
6
answers
12k
views
Why is RAID 1+6 not a more common layout?
Why are the nested RAID levels 1+5 or 1+6 almost unheard of? The nested RAID levels Wikipedia article is currently missing their sections. I don't understand why they are not more common than RAID 1+0,...
- 358
16
votes
4
answers
7k
views
Linux mdadm software RAID 6 - does it support bit corruption recovery?
Wikipedia says "RAID 2 is the only standard RAID level, other than some implementations of RAID 6, which can automatically recover accurate data from single-bit corruption in data."
Does anyone know ...
- 1,328
16
votes
1
answer
3k
views
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 ...
- 306
13
votes
4
answers
10k
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 ...
- 388
13
votes
1
answer
2k
views
RAID 6 array, one disk rebuilding?
I have got a 10 disk (16 TB) RAID-6 array (AVAGO MegaRAID SAS 9380-8e) in a Supermicro JBOD enclosure. The controller started beeping today and one disk is blinking red/blue. I entered the AVAGO ...
- 233
11
votes
2
answers
7k
views
Windows Storage Spaces - a useful replacement for RAID6?
// short update at the bottom
// another update is near the bottom to reply to a suggested edit
So, at first I had this idea: Find a virtual driver to set up and use software raid on windows. Result: ...
- 119
10
votes
2
answers
2k
views
Areca 1280ml RAID6 volume set failed
Today we hit some kind of worst case scenario and are open to any kind of good ideas.
Here is our problem:
We are using several dedicated storage servers to host our virtual machines. Before I ...
- 199
9
votes
3
answers
2k
views
Is it safe to write data to a RAID 6 while it's rebuilding?
I have a test RAID controller on my network which hosts a very large RAID 6 (11 drives, 3TB each). One of the drives failed, and the array is now rebuilding. At this rate, I think it will take about 3 ...
- 1,013
9
votes
4
answers
71k
views
Minimum number of disks to implement RAID6
RAID6 is intended to provide fault tolerance in the event 2 disks fail.
What is the minimum number of disks required to implement RAID6?
thanks
- 211
8
votes
2
answers
679
views
Is it possible to ask ReFS to use hardware RAID6 for parity calculations?
Does ReFS use FPGA-based XOR engines for RAID parity calculations? If not, is it possible to get it to use such tech?
- 889
8
votes
4
answers
6k
views
Optimal RAID 6+0 Setup for 40+ 4TB Disks
I am setting up a JBOD containing 44 4TB 7200 RPM SAS HDs. I chose RAID 60 as I prefer drive failure protection over the performance improvements offered by RAID 10. My issue is how to choose the ...
- 371
7
votes
2
answers
17k
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....
- 71
6
votes
1
answer
8k
views
3Ware 9650SE RAID-6, two degraded drives, one ECC, rebuild stuck
This morning I came in the office to discover that two of the drives on a RAID-6, 3ware 9650SE controller were marked as degraded and it was rebuilding the array. After getting to about 4%, it got ...
- 276
6
votes
1
answer
2k
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 are ...
- 445
6
votes
1
answer
931
views
RAID6 resync with fast writes but slow reads
I'm using Debian Jessie.
# uname -a
Linux host 4.9.0-0.bpo.3-amd64 #1 SMP Debian 4.9.30-2+deb9u5~bpo8+1 (2017-09-28) x86_64 GNU/Linux
And have setup a RAID6.
# cat /proc/mdstat
Personalities : [...
- 304
5
votes
1
answer
1k
views
How to recover mdadm raid6 array? mount: can't read superblock. 8/13 drives show all drives present, 5/13 drives show only 5 drives present
I rebooted my server today to find it hanging. I commented out the entry in fstab that loads /dev/md0 and the machine proceeded to boot. The raid was accessible and working prior to the reboot, I only ...
- 171
5
votes
1
answer
982
views
Linux mdadm --grow RAID6: Something wrong - reshape aborted
I have a RAID60 that I want to expand.
The current is: 2 axles each having 9 disks + 2 spares.
The future is: 4 axles each having 10 disks + 1 spare.
So I need to do some --grow to reshape the ...
- 3,026
5
votes
1
answer
493
views
3 drives fell out of Raid6 mdadm - rebuilding?
i had an mdadm raid6 array with 13x1TB drives. Within 10 minutes 3 of these drives fell out of the array... we assume bad cable to the controller card and replaced, however now we need to get the ...
- 51
5
votes
2
answers
2k
views
Linux software RAID6: rebuild slow
I am trying to find the bottleneck in the rebuilding of a software raid6.
## Pause rebuilding when measuring raw I/O performance
# echo 1 > /proc/sys/dev/raid/speed_limit_min
# echo 1 > /proc/...
- 3,026
4
votes
2
answers
1k
views
Why does ZFS RAIDZ2 only use 2GB of data when I create a 1GB File
I have created a ZFS RAIDZ2 / Raid 6 file system, which from what I believe will store parity on 2 disks.
root@zfs-demo:/data# zpool status
pool: data
state: ONLINE
config:
NAME ...
- 215
4
votes
2
answers
1k
views
Linux mdraid RAID 6, disks drop out randomly every few days
I have some servers that run Debian 8 with 8x800GB SSD configured as RAID6. All disks are connected to a LSI-3008 flashed to IT mode. In each server I also have a 2-disk pair as RAID1 for the OS.
...
- 41
4
votes
1
answer
1k
views
XFS very slow on LVMed Raid 6
i have a new storage server with 6 x 8TB WD Red HDDs. They build a RAID 6 with mdadm and a chunk size of 256k. On top of that mdraid i have LVM which then holds the different filesystems.
Initially i ...
- 758
4
votes
1
answer
1k
views
Backup Solutions for 20 TB of data [duplicate]
First, some background on out situation. We're a small-medium business who has around 20 TB of data on two different NAS's, and that number grows by at least 10% annually. 90% of this data we need to ...
- 41
3
votes
1
answer
482
views
recover highly degraded raid array
I have a Linux RAID6 array (mdadm) composed of 8 disks.
2 disks failed. I replaced them, now I have 2 new empty disks.
I would like to rebuild the raid
but
when I start a raid rebuild, the rebuild ...
- 1,817
3
votes
2
answers
288
views
Remove second RAID6 drive during resync from first failure?
I have a RAID6 comprised of five 1TB drives in good working order. I'd like to redistribute the array differently in my system (change the drive distribution over controller cards). I pulled the first ...
- 1,158
3
votes
2
answers
23k
views
LSI MegaRaid warning: Patrol Read can't be started
We run a HyperV server on RAID-6 (the OS is Windows Server 2008 R2). The hardware is LSI MegaRaid SAS 8704EM2 controller, with 4x 1TB WesternDigital SATA drives. The server is up & running on this ...
- 131
3
votes
2
answers
5k
views
ZFS: 3 devices: what's the difference between mirror and raidz2?
It would seem like with 3 devices, it's possible to configure a ZFS pool with either mirror or raidz2 mode.
What's the difference in performance and reliability?
(In regards to reliability, I'm ...
- 14k
3
votes
1
answer
501
views
Abort raid6 expansion on Adaptec 52445 SATA RAID?
I am expanding my raid6 array from 18x2Tb to 20x2Tb disks and after 3 weeks status shows:
Logical device Task:
Logical device : 0
Task ID : 105
Current ...
- 140
3
votes
2
answers
1k
views
How to diagnose intermittently slow raid data transfer rate?
I have an encrypted RAID6 set up on Centos 5.5. When I transfer a large 10gb file from the raid to my computer it will pause at around 4-5gb and again at 9gb. The data transfer drops from 25mb/sec to &...
- 131
3
votes
2
answers
12k
views
RAID6 setup - adding additional drives
I want to setup a dedicated server. To begin with we need a minimum of 8TB. I believe I can begin with 6x2TB drives in a RAID6 setup to achieve this.
Now when I need to increase this capacity to 10TB....
- 1,205
3
votes
1
answer
3k
views
How is the HPE SSA "remove drives" command supposed to work to shrink an array?
I have an HPE ProLiant DL380 Gen9 Server with 15 internal 8TB SAS LFF drives, in a RAID6 configuration through an HP Smart Array P840ar controller. It contains a single 94.6 TB Logical Drive [Size: ...
3
votes
1
answer
3k
views
Upgrading RAID6 drives with larger capacity (Best practices)
I have been tasked with upgrading an existing RAID6 array with new disks. Currently we have a 6 disk setup with 1 hot-swap. This is inside a Dell R340 with a PERC H730 Mini controller. I have not been ...
3
votes
1
answer
2k
views
Expanding RAID6 with LVM
My question is a bit broader than the question title, but here is my situation: I have Synology Hybrid Raid (SHR) built on 2 x 2TB drives. I want to migrate to a software-RAID on a homegrown linux ...
- 131
3
votes
1
answer
229
views
Adding a disk to an existing RAID fails with "disk doesn't have enough capacity"
I have a very old physical server using many disks in a number of RAID6 group. Those disks are not in the same chassis, instead is a JBOD system connected through the RAID controller on this server. ...
- 131
3
votes
1
answer
230
views
mdadm raid6 recovery reads more from one drive?
I just replaced a fault drive in my raid6-array (consisting of 8 drives) during the recovery I did notice something strange in iostat. All drives are getting the same speeds (as expected) except for ...
- 31
3
votes
1
answer
265
views
HP Smart Array P812 - Why is my Raid 60 gone?
I've got an HP ProLiant DL380 Gen7 with a Smart Array P812 which is connected to an MSA20 that houses 19 600GB drives.
After my VMs didn't boot up, I checked my array config and 2 drives failed:
=&...
- 41
3
votes
0
answers
499
views
What could go wrong with ext4 on LVM on a hardware RAID6?
Intro
Recently one of my systems using ext4 on LVM on hardware RAID6 experienced a disastrous failure. To name some of the disasters: several filesystems failed beyond repair, at least one was ...
- 219
2
votes
3
answers
2k
views
Need to recover RAID 6 array
By definition
RAID 6 is an array of independent hard drives equipped with two
independent and distributed checksum schemes
Does that mean I can recover each of the hard drives one by one using ...
- 121
2
votes
5
answers
3k
views
Which disk is bad in raid6 array
Server: Ubuntu Lucid
RAID controller: Adaptec 3805
8 disks in RAID6 on HP Proliant DL180 G5 Hardware
My kern.log tells me that I have an error on sdb, as shown below:
[2740390.344436] sd 4:0:1:0: [...
- 55
2
votes
4
answers
734
views
Which RAID format is best for data privacy during RMA?
So there are several RAID configurations to chose from, and I was wondering, eventually I expect some 25-45% of my drives may need to get swapped for a warranty repair. I know that there is no hope ...
- 157
2
votes
2
answers
3k
views
mdadm RAID6 to RAID60
Is it easy to convert a RAID6 to a RAID60?
Right now, I have an 8-drive RAID6. I'm looking to upgrade to a 3U 16-bay system and thinking of having a 16-drive RAID60. Is it possible to move my ...
- 800
2
votes
2
answers
231
views
Progressive upgrade of a RAID array
I have a 16 disk backup RAID6 array. Currently, those 16 disks have the following specs;
500 GB
16 and 64MB cache
3 Gb/s SATA
I would like to begin upgrading these disks if possible, primarily for ...
- 471
2
votes
1
answer
272
views
(Why) Does lvmraid6 need 5 drives?
I'm investigating using LVMRAID instead of MD+LVM. In my case, I'm looking at a RAID6.
As expected, the docs say you need N+1 devices for RAID5, and a minimum of 3 drives.
The docs say for RAID 6 ...
- 1,825
2
votes
1
answer
1k
views
How to create degraded raid6 array using megacli
There is a server with few disks. And - a new server with PERC controller.
I would like to migrate existing data into a new server to raid6 which uses 6 disks(4+2).
Unfortunly - i don't have enought ...
- 1,056
2
votes
4
answers
957
views
RAID6 failed instantly and switched to RAID0 - any chance to rescue?
I´m running a server ob Ubuntu 16.04. Data storage on this system uses a lvm on top of a software raid 6 whereas the os is installed on a separate raid 1 with lvm.
The raid 6 is built up of 7 ...
- 21
2
votes
1
answer
2k
views
Concerns of simultaneous failure of SSD Raid1
Since SSD's have a write limit requiring wear leveling one would assume that all things being equal 2 identical SSD drives would wear nearly identically if they mirror data writes. When one drive ...
- 257
2
votes
1
answer
6k
views
How is the parity calculation in a RAID 6? [duplicate]
In a RAID5, the parity block is a XOR calculation of the rest of blocks but, in a RAID6, the second block parity is the XOR calculation of what blocks?
http://upload.wikimedia.org/wikipedia/commons/...
- 39
2
votes
2
answers
516
views
PERC 6i / RAID 6 failures
I've got a new server that I'm trying to install a RAID6 config on with a PERC 6i controller and 6 cabled drives.
I installed the card, battery and cabled the drives and all looked fine. I installed ...
- 4,028