Tagged Questions

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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0answers
50 views

Backup Solutions for 20 TB of data

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 ...
2
votes
1answer
45 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 ...
0
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1answer
33 views

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 ...
0
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1answer
49 views

RAID6 generates quite a IO wait at relatively low TPS

I have a RAID6 array made of 9 SATA3 disks @7200 RPM, 4TB in size. I have them partitioned with Gparted Live as GPT partitions, starting at the first megabyte. I am concerned about the read speed. ...
1
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1answer
58 views

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; ...
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1answer
191 views

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. ...
0
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2answers
61 views

soft raid6 recover second disk fault

I had a disk failure in a hosted system and had the failed drive replaced. During recovery, a disk error on a different drive occurred. when the original error occurred: md2 : active raid6 ...
0
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1answer
92 views

S/W RAID6 and 4k sector format — slow resync

I'm looking for reason why Linux software RAID-6 re-sync is much slower than I expected. I have used 6 WDC WD40EFRX HDDs (with 4k physical sectors) to create RAID-6 array. $ sudo mdadm -v -C ...
0
votes
1answer
97 views

System wont boot from degraded RAID6

I have a Debian Wheezy with 3 Partitions as RAID6. MD0 is for Root and OS, MD1 is for SWAP and MD2 for Files. While copy files to MD2 the system reports kernel panic and halts. I have had shutdown on ...
2
votes
1answer
60 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 ...
1
vote
0answers
135 views

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 ...
0
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0answers
84 views

Intransa Server Failure/Software

Our agency has an IntransaBrand VideoAppliance storage server. It is currently running a Windows Vista client on server equipment and has 2 RAID arrays. One is a RAID 5 (4 x 2TB Western Digital ...
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3answers
295 views

mdadm raid6 built, but no mounting or fsck

I had some problems with my RAID 6 drive on mdadm recently. No LVM in between. Two drives died, and were pulled out while the machine was powered down. Now, I boot up the system, and cannot mount the ...
0
votes
2answers
692 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 ...
2
votes
2answers
383 views

Strange performance issue with Dell R7610 and LSI 2208 RAID controller

Connecting controller to any of the three PCIe x16 slots yield choppy read performance around 750 MB/sec Lowly PCIe x4 slot yields steady 1.2 GB/sec read Given same files, same Windows Server 2008 ...
-1
votes
1answer
948 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? ...
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0answers
30 views

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 ...
0
votes
1answer
198 views

Which partition size for fresh install Debian Wheezy with 6 Disk in Raid?

i want to install Wheezy on a System with 6x3TB Disk. The aim is to use the most of it for a samba share. My idea is to make: 1 partition on each disk for gpt with 100MB 1 partition for "/" with 3GB ...
2
votes
1answer
185 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 ...
1
vote
1answer
144 views

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 ...
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votes
4answers
258 views

Hardware Acceleration for MD RAID?

Is it possible, or feasible, or even sensible to consider hardware acceleration for MD RAID? I am referring more here to RAID6 type levels where there is a computation overhead. My thinking is that ...
2
votes
2answers
83 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 ...
1
vote
1answer
61 views

Safest approach when designing storage server [duplicate]

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 ...
0
votes
2answers
133 views

Disabling Server 2003 Wonderware App Server Page File on VMware

There are so many threads on whether you should mess with the page file or not. This scenario describes a unique circumstance that is real world in my production enviornment. The conclusion I've ...
5
votes
1answer
312 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 ...
1
vote
0answers
93 views

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 ...
0
votes
1answer
798 views

3ware raid controller, unit unusable, several degraded disks

I was switching the disk drives in my server, running RAID 6 on 5 disks on a 3ware 9650SE controller, for newer disks and have run into a problem. The two first disks went fine, I took out one disk ...
3
votes
1answer
435 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 ...
3
votes
1answer
230 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 ...
1
vote
1answer
483 views

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 ...
1
vote
1answer
816 views

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 ...
0
votes
1answer
359 views

mdadm: superblock on /dev/sdd1 doesn't match others - assembly aborted

OS: Debian Squeeze Kernel: 2.6.32-5-amd64 mdadm version: 3.1.4 (31 August 2010) mdarrays md1 = raid1 (this is working) (devices: /dev/sd[fg]1) md0 = raid6 (previously raid5, ...
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votes
7answers
740 views

Which RAID/LVM configuration for new 2x8TB file server is safest?

I just built a totally new PC to be a fileserver. It has one 60gb SSD for OS (ubuntu 12.04), and 8 2tb data drives in it. I am looking for the safest, most stable way to set up a single giant ...
4
votes
1answer
372 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 ...
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votes
2answers
1k views

High IO latency on ESXi 4.1 on HP DL580 G7

at my Company we were experiencing some weird spikes on IO latency on one of our ESXi instances. we've spend 24h figuring out whats wrong and no clue so far. after giving up we put all the disks ...
4
votes
1answer
3k 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 ...
6
votes
2answers
4k 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 ...
8
votes
2answers
2k 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
votes
1answer
450 views

3ware 9650SE-24M8 INOPERABLE data recovery

I have a raid6 array with 16 hdds. Two harddrives had failed (device error), but when I went to replace them, I pulled out one wrong disk! Now the raid array is INOPERABLE. Is there any way to ...
9
votes
2answers
974 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 ...
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 ...
3
votes
3answers
758 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 ...
3
votes
1answer
194 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 ...
0
votes
1answer
705 views

HP Storageworks MSA60, one failed disk replaced, all 12 bays flashing rapidly

I replaced a faulty disk yesterday afternoon, and the rebuild process started (RAID6). All disks were previously 750GB, but the only disk I could get is 1TB. Right now, almost 18 hours after replacing ...
1
vote
1answer
7k 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 ...
0
votes
2answers
356 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 ...
0
votes
2answers
497 views

How to identify RAID (5 or 6) controllers that allow dynamic resize of the array

I'm building a server with a RAID5 array, based on a hardware controller. I want to be able to later add additional disks and have the array rebalance across all of the disks, enlarging the usable ...
3
votes
2answers
876 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 ...
1
vote
2answers
2k 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 ...
1
vote
3answers
845 views

mdadm & raid6: does “re-create(with different chunk size) + resync” destroy orig. data?

I would like to rescue data on my software raid-6 array. I did some stupid actions (described bellow) with this original array. Main Question: I need to know if original data stored on raid-6 array ...