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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Proper way to identify member devices in mdadm.conf

My current mdadm.conf looks like: $ cat /etc/mdadm/mdadm.conf DEVICE /dev/sdb1 /dev/sdc1 ARRAY /dev/md0 metadata=1.2 spares=0 UUID=357ff7cc:55e78d18:9fc7917b:f5b253f2 MAILADDR me@example.com Since ...
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69 views

Popped in replacement harddrive in RAID 1 configuration; Seeing I/O but the drive is not recognized by OS or RAID controller

CentOS 5.11; Dell PowerEdge R410; Dell SAS 6/iR Integrated Blades RAID Controller. Have two drives, both in a RAID 1 array. First drive failed. Pulled it out and popped in a new drive (same brand ...
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42 views

How to add disk back to RAID and replace removed

Received a message that RAID went into degraded state: Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid1 sda1[0] sdb1[1] 524224 blocks ...
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31 views

HP P212 RAID + Tape Library = Kernel Panic

I have a HP DL320e g8 v2 server running CentOS 7.1 (kernel 3.10.0-229.4.2.el7.x86_64). The onboard B120i SmartArray was disabled, and a PCI-Express P212 SAS HBA was installed with two identical 3TB ...
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1answer
115 views

HP B120i RAID0 very slow to read data from disks

I have a HP DL320e g8 v2 server running CentOS 7.1 (kernel 3.10.0-229.4.2.el7.x86_64). This server comes with a B120i onboard SmartArray controller, and it was configured with two identical 3TB ...
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21 views

Systematic deletion of files from RAID drive

I have a client with a Mac Pro and an two undetermined RAID storage systems from Areca, running off of an internal MRAID card. They are currently using the primary RAID array for working files, and ...
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3answers
164 views

Hard disk / SSDs - detection and handling of errors - is silent data corruption reliably prevented?

When an error occurs on a drive, is it correct to assume that it will always be detected and reported to the OS (if software RAID such as mdadm) or RAID controller (if hardware RAID) as a failed read ...
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2answers
87 views

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

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
56 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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355 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
60 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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36 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
72 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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39 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
60 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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1answer
35 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
47 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
44 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
41 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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69 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
37 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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1answer
89 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
83 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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49 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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40 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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41 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
94 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
50 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
98 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
45 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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0answers
27 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
38 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
39 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
137 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
139 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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5answers
3k 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 ...
4
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2answers
590 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
338 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
116 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
128 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
32 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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84 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 ...
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53 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
52 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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182 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
44 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
139 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
74 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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139 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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32 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 ...