RAID, an acronym for Redundant Array of Independent Disks (sometimes incorrectly referred to as Redundant Array of Inexpensive Disks), is a technology that provides increased storage functions and reliability through redundancy. -Wikipedia

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Mdadm - detection and handling of unrecoverable read error

When an unrecoverable read error occurs on a drive, is it correct to assume that it will always be detected and reported to the OS as a failed read (i.e. it won't silently return corrupted data), and ...
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12 views

Create LVM2 volume group on top of RAID1 array

Basically, I have sda and sdb in RAID1 (mirroring). The RAID device is md0. I need to create a volume group on md0. I boot the OS from this RAID array. The command pvcreate /dev/md0 returns Can't ...
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2answers
38 views

Should I defrag RAID Array with SSD caching(Intel SRT)? [on hold]

I have an SSD in system and a RAID 0 array with SSD caching turned on(Intel SRT or Intel Smart Response Tech.). Should i defrag it? Also have a problems with windows defragmentator. It detects my ...
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2answers
33 views

Where do md array definitions come from?

I created a md array in an ARM computer with two USB/SATA disks in RAID 1. Then I moved both disks to my Ubuntu desktop and installed mdadm. Installation detected the RAID and added the definition to ...
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2answers
189 views

does adding heaps of drives to a raid 0 increase performance?

does adding heaps of drives to a raid 0 increase performance? i know that two drives in a striped raid will usually be faster than a single drive but will i notice a difference in performance between ...
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2answers
16 views

MegaCli create virtual drive from new disk (is it dangerous for the existing array?)

This is a linux system with a MegaRaid controller. MegaCli is installed. I currently have: Virtual Drive: 0 (Target Id: 0) Name : RAID Level : Primary-6, Secondary-0, RAID ...
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21 views

MD RAID Array Often Starts Without All Drives

I find that, when I start/restart my system, my MD array often doesn't start with all of the drives even though the device-names haven't changed at all. I'll have to stop the array and reassemble it, ...
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1answer
29 views

Linkstation WXL: RAID disappeared, /dev/md2 is inactive - how to troubleshoot

today I had problems accessing the SMB-share on my Linkstation. My NAS has two hard drive disks, configured as raid0. this raid was mounted to /mnt/array1/intern - the folder that i am missing. My ...
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0answers
24 views

why are zfs on linux transfer rtates reported incorrectly after expanding array?

I have upgraded the drives in a 4 drive Raidz array in a NAS server and the array has auto expanded to the new size. In testing transfer rates from the NAS server now I observe that when performing ...
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1answer
56 views

Multiple DSLs connected to single HP server

networking noob here! Got a pretty specific question. Is it possible to plug 10 cat5 (network) cables that come from 10 different DSL modems to an HP server so I have 10 different broadband lines ...
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37 views

DELL PowerEdge 2900, Perc 6/i Lost RAID 50 configuration after one disk failure

I have a Dell PowerEdge 2900 server with 10 SCSI HDDs that were configured in a RAID 50 Array. After a couple of year's of good use, the server became unresponsive today. It appeared to me that one of ...
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36 views

How to configure H700 raid on Dell R610 with no OS [closed]

Ok, I am a noob to dells. We have inherited a stack of R610s with 6 SAS drives each, and now I need to install vpshere 6 on some and ubuntu on others. There are two problems: how do I configure ...
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1answer
22 views

PCI RAID Controller Card bandwith for a RAID1 array of SATA III drives

I want to build a hardware RAID1 setup with two HDDs (SATA3, 7200, 64MB cache) and I'm looking at two, almost the same, Adaptec cards (6405E vs 6805E) The 6405E is PCI-E 2.0 x1 while the 6805E is ...
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1answer
36 views

Does this partition setup look OK for Centos 6.x and Plesk panel?

I have a new server with 2x3TB HDD, I want to setup software raid 1; When I use host's automatic install it makes my largest partition 2TB and the other 1TB a separate partition (not nice). So I am ...
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1answer
33 views

Can I recreate a unit from a single drive RAID1 in a 3ware Raid controller?

I have a broken server and a broken disk on that same server on a RAID1 setup. I need to setup this same RAID unit, now on a new server, and from only 1 drive (since the other is broken). I moved ...
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0answers
20 views

Stress Test Hard Drive attached to a LSI controller on Hyper-V

I have a LSI 9265-8i controller running on Hyper-V. How can I stress-test the hard disks in-situ? I'd like to test things like iOPS, seek times etc.
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21 views

LSI Raid controller: identifying failing hard disk (MegaCLI)

Info: I have a LSI 9265-8i controller. It's been running pretty well for two years. More recently it looks like a drive may be failing - no errors reported and no media issues reported when viewing ...
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1answer
30 views

Copy OS from degraded array to another RAID 1 array

We have a degraded (second drive is not recognized at all) RAID 1 array with Windows Server 2008 R2 installed. I'm using CopyWipe from a boot floppy to image the new array. It should be mentioned that ...
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13 views

No Raid available in Redhat Hypervisor

We purchased Supermicro Server "SUPERMICRO CSE-827H-R1400B" . And each of its node has 9TB Storage . And we planned to use this server as a Host for Virtual Machines. So i started to install the ...
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1answer
57 views

Are RAID 5 systems suitable for larger disk sizes?

Why is it generally considered that RAID 5 systems are not suitable for larger disk sizes? Is the same true for RAID 6?
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1answer
53 views

How to combine multiple disks to act as one larger one?

In EC2 the i2.2xlarge (or i2.4xlarge) instance type come with 2x800 GB SSD (or 4x800 GB SSD) for instance storage. Is there a way (using RAID?) to make these separate disks be treated as a single ...
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38 views

File IO being slow

I've rented this root server with a RAID1 mdadm software raid setup. Using dd to benchmark the file IO speed it achieves 230MB/s write (default blocksize). Certain tasks such as mysql are way slower, ...
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0answers
26 views

Can I use external SFF-8088 connector as a inexpensive way to get 2 more internal SFF-8087 ports?

Here's the scenario: I'm shopping between the LSI MegaRAID 9280-16 and 9280-24. Both cards have a single external 8088 connector, but the difference is whether they have 6 or 4 8087 internal ...
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19 views

Intel Rapid Storage Technology install failure [migrated]

When I try to install IRST, it runs for a bit and then a popup appears saying that setup.exe had a problem. Expanding the details produces this: Problem signature: Problem Event Name: ...
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20 views

How to change bootable logical drive via arcconf (Adaptec 6805 controller)

I've got an Adaptec 6805, with two RAID 6 arrays attached - 4 drives each. I'd like to change which of the two is the one that it boots from. Is there any way to do that with the Adaptec 'arcconf' ...
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0answers
48 views

Dell C2100 - Replacing Per 6/i with Perc H200

I have been googling a bunch this morning and am having a hard time verifying that my setup is going to work and was wondering if i could get some quick feedback/advice. I have a Dell C2100 which ...
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1answer
39 views

Remove a drive from a 2-drive RAID 5 array using version 1.2 metadata?

My situation is nearly identical to "How to remove a drive from a non-standard 2-drive RAID 5 array?", except my 2 TB RAID5 is using mdadm super block version 1.2. According to the best answer, ...
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2answers
50 views

NAS RAID5 & Crash Scenarios

I need to validate my understanding on RAID. I'm planning to buy a Synology (or QNAP) NAS and plan to mount 4 HDD (4To each) in a RAID5 group. I’m considering several crash scenarios : one hard ...
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1answer
31 views

Recovering data from a RAID built with fakeraid [closed]

I have (had) a motherboard that supports (supported) fakeraid, which I used to build a RAID 1 with 2 WD Red 1TB. My motherboard died (as you would have guessed already) and now I have 2 options: Buy ...
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22 views

BTRFS new device cannot be added

I have a raid10 setup with btrfs with 5 disk currently: Total devices 5 FS bytes used 6.89TiB devid 1 size 3.64TiB used 2.83TiB path /dev/sde devid 2 size 3.64TiB used 2.83TiB path /dev/sdd ...
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1answer
31 views

Recover overwritten RAID5 array (XOR)

as I've mentioned in a recent question (RAID5 rescue with LVM2 running on it) I'm rebuilding an RAID5 array. Now, I think that the initial wrong mdadm --create ... command has started the ...
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1answer
26 views

Ubuntu - Folder replaced by lost+found/ on raid1 disks

Running Ubuntu Server 12.04 LTS I have setup a RAID1 on disks sdb & sdc (md0) following strictly this tutorial which I guess is very classical. I loaded data on my disk for archive purposes. A ...
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1answer
88 views

Low SSD mdadm raid0 performance

I have got ubuntu server 12.04 with software raid0 intel sata3 ssd(2*480GB). raid is used for postgresql database. There is 51% of raid space is free. After postgres shutdown, "dd" command shows ...
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1answer
47 views

Does the amount of disks in a RAID10 matter for a Microsoft SQL server in regards of the block size?

We are planning to deploy a Microsoft SQL Server and to store the databases on a RAID10 (RAID1+0) block-level-storage. Does it matter how many drives altogether I put into the array for optimum ...
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4answers
1k views

Software vs hardware RAID performance and cache usage

I've been reading a lot on RAID controllers/setups and one thing that comes up a lot is how hardware controllers without cache offer the same performance as software RAID. Is this really the case? I ...
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2answers
235 views

Samsung 850 EVO + HP P410 limited iops?

I´m experiencing a weird write iops limitation with a HP P410 256mb cache controller and 4x consumer grade ssd´s (Samsung EVO 850) in RAID5/10. After upgrade to latest firmware (6.64) for HP P410 ...
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1answer
320 views

Rotate entire disk set in RAID0 array?

We have a Lenovo RD430 with a RAID 500 controller. Installed in the server are 6x 4TB drives configured as 2x RAID0 arrays of 3x 4TB each, however, we also have another 3x identical 4TB drives and ...
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2answers
76 views

After power loss, my RAID config changed, some drives marked as foreign, but all data still there

I have a Perc 5/i in a Dell Precision 590. The controller DOES have a battery backup, and the controller reports that its status is healthy. There are five 1TB SATA drives connected to the controller. ...
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3answers
69 views

Resize RAID partition with GPT partition layout, without LVM

OK so I am a freelance sysadmin. I was asked to resize root partion (/) because it was 20Gb and /home was 3Tb. What I wasn't told is that the server is using RAID and GPT, so I can't use fdisk but ...
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0answers
30 views

Proper Partition Alignment

I'm trying to follow the advice from this TechNet article about partition alignment. Our San is an EMC, the disks are in a 4 disk raid 10. This services an I/O intensive application, 60:40 write:read. ...
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0answers
33 views

Proxmox VMs Fail to start on reboot due to unmounted drives

For whatever reason, I have to re-assemble my RAID arrays on boot, I don't know why, and Ive banged my head against my desk over that issue to much already, so I put the RAID mdadm commands in ...
2
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0answers
46 views

Raid 1 seeding to speed up identical installs

I was thinking of installing Ubuntu on one of our Dell servers in a RAID 1 configuration, then using the mirrored drive as the primary drive in a second identical server with another RAID 1 setup. ...
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1answer
28 views

Do I need FIS-based switching for Linux software RAID when *not* using a port multiplier?

I'm planning to build a home NAS with an ASRock AM1H-ITX with four S-ATA disks. According to the manual the board features two S-ATA controllers: 2 x SATA3 6.0 Gb/s Connectors by AMD AM1 Series ...
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71 views

Get disk serial number by smartctl under raid0 of LSI

I'm trying to get the disk serial number of disks attached to the Centos server. When there was no raid0 (under LSI), I can get the serial number and model of /dev/sdb by: smartctl -i /dev/sdb and ...
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1answer
36 views

How do I prevent Windows from presenting software RAID discs as a single volume?

Here's my issue: I had a server's software RAID fail. I don't believe it's the hard drives, as they are brand new RE drives from Western Digital and the RAID software said that 2 dives had failed. ...
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1answer
65 views

HP DL360 G5 RAID controller not recognizing drive bays 5 and 6

I have an HP DL360g5 bios P58. With a Slot 0, HP Smart Array P400i Controller (256MB v2.08) The server originally was running Windows Server 2003 with 2 72GB 15k SAS drives in RAID0. One of the ...
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2answers
67 views

What is RAID 5 write logic with 8 drives running SQL 2008?

We recently had a raid array fail on a SQL 2008 server with 8 x 73GB drives. (Dell 2950). There were two drives that went bad (one had been bad for a few months it seems and was not caught...). To ...
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73 views

Unable to install grub to software Raid array in Ubuntu

How do you ensure Grub is properly installed on a software RAID array in Ubuntu? I have a failed RAID array on an Ubuntu 14.04 server. When I first tried booting it, the Grub screen came up, but ...
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21 views

How to diagnose RAID drive showing incorrect size

I have a software RAID1 array on Ubuntu 14.04. Each drive has 1TB, for a logical size of 500GB. Suddenly, one drive started reporting it only had 4.1GB and I can no longer run any SMART self tests on ...
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1answer
49 views

How to fix destroyed software RAID after Ubuntu upgrade

I upgraded a headless server from Ubuntu 12 to 14 following the built-in do-release-upgrade script. It seemed to run fine until I rebooted, and was left with an unusable machine. After the grub ...