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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Risky to have RAID5 with 3x3TB drives? What alternatives should I be considering?

A drive dropped out of my raid 5 array yesterday. It looks like the reason was due to a bad controller so I switched it out and attempted to re-add the drive but mdadm claimed it couldn't do it. So I ...
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0answers
107 views

What should I know before I set up RAID 6 on Linux?

I just ordered five 1TB drives to install as a RAID 6 array in a Linux server (keeping the existing 1TB drive as a boot disk). I want to use Linux MD for RAID rather than a RAID card, to avoid ...
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4answers
470 views

When using RAID10 + BBWC why is it better to separate PostgreSQL data files from OS and transaction logs than to keep them all on the same array?

I've seen the advice everywhere (including here and here): keep your OS partition, DB data files and DB transaction logs on separate discs/arrays. The general recommendation is to use RAID1 for OS, ...
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1answer
624 views

raid10 in mdadm reports incorrect “Used Dev Size”

I previously had a raid5 with mdadm using four 2TB drives. I've recently disassembled the raid and created a raid10 with six 2TB drives, but mdadm --detail is showing "Used Dev Size" as only 2TB (the ...
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1answer
944 views

Server 2008 R2 - Boot disk RAID 1 - migrate to larger disk

My group inherited several 2008 R2 servers with single 70GB RAID 1 boot/system disks. No other disks in the servers. We need larger boot / system disk. Plan is : to replace one disk with new 500 ...
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1answer
440 views

ML 350 additional SATA RAID controller (mirror only)

I have a Proliant ML350 G8 with two SAS raid arrays currently set up - thereby maxing the default P420i raid controller. I need to set up a large video dump space in addition to this existing set-up ...
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4answers
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Do raid controllers syncronize HDD platter rotation?

I'm in the market for a new storage solution. While researching various specs one of my coworkers said that some raid controllers can synchronize HDD rotation to the effect of all drives' sector/block ...
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258 views

RAID disk not booting

my hosting facility replaced disk /dev/sda for me and I've added it to the RAID via sgdisk -R /dev/sda /dev/sdb mdadm /dev/md0 -a /dev/sda1 mdadm /dev/md1 -a /dev/sda2 mdadm /dev/md2 -a /dev/sda3 ...
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33 views

Backup RAID1 and RAID10 before upgrade

I have two machines, one with mdadm RAID 1 on root partition and one with mdadm RAID 10 on root partition with 4 drives. Ubuntu machines, now I need to upgrade these. If something goes wrong I need a ...
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1answer
119 views

Building hybrid RAID10 + RAID5 environment

I have the following configuration: simple video surveillance system (server 1: recording past 24h; server 2: recording past 30 days). I am primarily using the content on the 24h storage, while I ...
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1answer
369 views

mdadm superblock hiding/shadowing partition

Short version: Is it safe to do mdadm --zero-superblock /dev/sdd on a disk with a partition (dev/sdd1), filesystem and data? Will the partition be mountable and the data still there? Longer ...
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2k views

HP PROLIANT ML110 RAID 1 don't rebuild

I have an HP Proliant ML110 G5 with RAID1 mirror. One disk is dead and I took a new disk (same size, rpm and model) and put on the bay, BUT the system doesn't see it... I believed that I had only to ...
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1answer
807 views

ZFS SSD Trim and Software Raid 5

I am trying to find if the ZFS filesystem has added support for Trim to Raid 5? I am setting up an SSD array in Raid 5. I also would like to know if there is any good software raid 5 alternatives to ...
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2answers
4k views

HP DL380 G5 Predictive failure of a new drive

Consolidated Error Report: Controller: Smart Array P400 in slot 3 Device: Physical Drive 1I:1:1 Message: Predictive failure. We have an HP DL380 G5 server with two 72GB 15k SAS drives ...
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1answer
1k views

Linux Software RAID: How to fsck on hard drive?

We have a Linux server running with Software RAID1. We see some issues in /var/log/messages like: unreadable sector. I want to perform a complete fsck on the drive to get some more information, but a ...
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1answer
141 views

Linux RAID: Replacing Failed Drive…permanantly

Okay, odd question here. I have a server with RAID 5. A drive failed, in a really physically in a really odd way. On the machine it boots and is seen by the BIOS but...no partition can be seen on the ...
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2answers
53 views

HP DL 380G7 Raid swap drives

disks 0 and 1 are raid redundant (OS) and the remaining 6 drives are in raid 5 I believe. i would like to pull out disks 0 and 1 and install new drives to build a new OS. I need to be able to ...
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1answer
588 views

Different block sizes for partition and underlying logical disk on HP Raid Controller (Linux)

Following links collected in this thread I started to check blockdev and found the following output indicating different sizes for partition c0d9p1 and the underlying device (c0d9): [root@machine ~]# ...
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2answers
334 views

Preventing h/w RAID cards from dropping slow JBOD disks

I'm considering buying a used SAS h/w RAID card for externally attaching HDDs to an HP ProLiant I'm setting up. However, I only require RAID functionality on some of the drives. Theoretically it ...
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2answers
71 views

RAID Controller Link Speed

I was wondering what sequential speed should I expect from a RAID controller that has 1 x MiniSAS 6Gbps port. In the product details -> Data Transfer Rates: Up to 6Gb/s per port Does this MiniSAS ...
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2answers
374 views

How to perform fresh linux install while preserving software raid and user accounts

I have a system with two software raid arrays. The OS is Ubuntu 9.04 and is no longer receiving updates. I'd like to update the system to 12.04 rather than trying to do the automatic update from ...
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0answers
127 views

Debian squeeze server hangs when accessing md raid 5 over network

My debian squeeze server ha begin to hang/freeze when I try to access my md raid 5 over network (via samba or afp/netatalk). This behavior started when I installed netatalk, libgcrypt11 from wheezy. ...
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1answer
392 views

What is the procedure to replace a failing hard drive in a RAID array?

3 years ago a co-worker setup a software RAID-6 array on Ubuntu 9.04 and I'm getting messages from the OS that the drive has bad sectors and should be replaced. I'd like to remove this drive and ...
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1answer
378 views

PERC 5/i Enable alarm on disks failures

I'm trying to enable one the alarm of my server's raid controller PERC 5/i. Using this documentation, under the chapter Audible Alarm Warnings, it's explained that enabling an audible alarm is ...
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1answer
163 views

Storage setup on Ubuntu Server used for running virtual machines with software redundancy

I have a server I would like to use explicitly for running virtual machines under Ubuntu Server 12.04. It has plenty of RAM, 64GB and three large identical HDD´s. I would like redundancy through ...
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1answer
990 views

What effect does RAID stripe size have on read-ahead settings?

I'm trying to figure out the correct read-ahead values to set on a RAID10 array, and I'm wondering if the RAID stripe size should factor into my considerations. I've heard conflicting information ...
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80 views

Raid - “Rebuilding up” the storage [closed]

Say I have a RAID 1 config of two 1TB drives. (1TB of storage) I take one out, insert a 2TD drive and let it rebuild. (Still 1TB of storage) Now I take the second one out, and insert a 2TB drive and ...
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1answer
132 views

RAID5 and different sizes of HDDs

Today I set up my first RAID ever. I decided to use RAID5, because I want as much space as possible, but I'm to afraid to use RAID0 because of possible data loss. I have 4 0,5TB drives and in RAID5 I ...
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2answers
102 views

Selecting a RAID Card That Will Work With Linux? [closed]

When selecting a RAID card for a project, how can I ensure that it is well supported under Linux (Debian 6)?
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1answer
81 views

DegradedArray event on /dev/md0 without actually having a RAID

Since I upgraded from Ubuntu LTS 10 to LTS 12, I have been getting error messages like: N 60 mdadm monitoring Mon Sep 3 06:38 31/1022 DegradedArray event on ...
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174 views

four-disk md raid10-far can be assembled and ran as “clean, degraded” with only 2 disks. Bug or i'm missing something?

Today i was solving raid failure on raid10-far with four disks. One disk failed and another wasn't re-added after a hard reboot. The mdadm -D was reporting it's clean and running with only two out of ...
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1answer
8k views

Virtual Disk Degraded

There is a physical DC with a Raid 1 Mirror, 2 Physical Disks, 500GB each. Dell Server Administrator is installed on the DC, and is reporting both physical disks are fine, online, in a good state etc. ...
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1answer
397 views

Linux software RAID5 on SSD. One SSD 40% more worn out than the others

We have a 6 SSD, RAID5 volume. The SSD disks we are using are Crucial M4-CT512M4SSD2 firmware 000F. We write 100 ~ 200GB data through MySQL InnoDB to the volume daily. The RAID5 volume is only used ...
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2answers
791 views

HP Proliant DL160 G6 - Hardware RAID card to get? [closed]

I have bought a DL160 G6 server (Product number: 490427R-001 ) and it does not come with a hardware RAID card. I am trying to set up a VMWare Esxi server and as such I would need a hardware RAID card. ...
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1answer
874 views

What is the default RAID-50 stripe size on a Dell EqualLogic PS6510?

We have a Dell EqualLogic PS6510 RAID Array. I have full access to the web-based "PS Group Manager" app, as well as the "SAN Headquarters" app. I have hunted high and low, and searched Google for ...
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1answer
1k views

Linux software RAID60: Can I have global hot spare?

As far as I can see Linux has RAID6 and RAID0, but not RAID60. So RAID60 is emulated by creating RAID0 on top of some RAID6s. It is possible to add a hot spare to each of the RAID6s, but is it ...
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0answers
1k views

Calculating correct stripe size for Linux mdadm RAID10 arrays in “far” layout

I'm creating RAID10 array from 6 drives. When created in near layout, e.g. mdadm --create /dev/md2 --chunk=64 --level=10 --raid-devices=6 --layout=n2 /dev/sda1 ... Checking stripe size as ...
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2answers
353 views

Alternative to software RAID for mirroring

I've read "on the interwebs" that Raid is starting to become an inadequate solution with todays large disks. As I've understood it, the rebuild time and the risks for rebuild failures are very ...
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1answer
5k views

Why has ESXi 5.0 not used the software RAID configuration on my test server?

I've got a test server which was running WS 2008 Enterprise on the bare metal. It was correctly using the software RAID 1 configuration (2x250 GB disks which appeared as one disk), setup on the Dell ...
0
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1answer
238 views

file read performance degrades as number of files increases

We're observing poor file read IO results that we'd like to better understand. We can use fio to write 100 files with a sustained aggregate throughput of ~700MB/s. When we switch the test to read ...
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votes
2answers
2k views

Using RAID1 vs. rsync pros and cons [closed]

I am building myself a Linux NAS/home server. I am considering either using sw RAID-1 (mdadm) to replicate data or alternatively just rsync them periodically. What are advantages/disadvantages of both ...
0
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1answer
204 views

How to recover data from a partially overwritten partition

By mistake, I configured a 900GB partition to be part of a 50GB raid. The sync is complete and my understanding is that only the first 50GB of the bigger partition is overwritten. How do I recover the ...
0
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1answer
384 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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1answer
284 views

Dell Poweredge 2900 SAS Raid 1 Data Consistency Check Failure

We have at work a Powerdge with two SAS drivers in a RAID1 configuration, it's been like this since way before I started but today we started getting disk access errors on the console so I took a ...
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2answers
20k views

Can't enter HP SmartArray P410 RAID ORCA set-up on HP ProLiant DL320G6

I've just installed an HP SmartArray P410 controller into my HP ProLiant DL320G6 server. The controller seems detected by the server BIOS (it shows up in controllers list in the BIOS set-up), hard ...
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2answers
736 views

RAID disk failure - Replace disk or whole array?

I have a 5 disk Raid5 array of Western Digital Green (WD10EADS) 1TB. Raid5 is via Windows Server (software raid). One disk has failed, and it looks as though I can't get the same model replacement. ...
4
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1answer
361 views

How to recreate a RAID 10 array with mdadm

So our virtual machine has broken (it's actually a Linux machine in Azure) on which we were running a RAID10 array of 4 disks. It's an ubuntu box. From what I can tell the four data disks are fine, ...
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1answer
286 views

Smart Array P212 Raid controller on SBS 2008 ProLiant G6

I had a mirrored array with 2 * 1TB drives. I have replaced both drives (one at a time and allowed it to rebuid) with 2 * 2TB drive. So I now have a capacity of 2TB rather than 1TB. However, the array ...
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4answers
2k views

Is it necessary to have RAID in a virtual machine?

I have a Windows 2008 Enterprise on RAID 10 running Active Directory, Hosted Exchange, and a web server on HyperV VMs. Do I need a virtual RAID for Exchange? If so, why? Edit: thanks everyone for the ...
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1answer
2k views

Does a RAID 1 really protect from HDD failure?

If using a RAID 1 and if there are any inconsistencies between both disks found, data is copied from the primary disk (most likely the one with the lower port number) to the secondary disk. 1) But ...