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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LVM over Raid 1 with different size disks in Ubuntu

I'm currently building a backup server for a few of the machines in the office. I plan to run ubuntu 10.04 LTS on it. My current setup is: 2 x 1TB disks in software RAID 1 configuration 2 x 2TB ...
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2k views

Why does MDADM Raid 5 require a spare

From the mdadm man page: "When creating a RAID5 array, mdadm will automatically create a degraded array with an extra spare drive. This is because building the spare into a degraded array is in ...
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973 views

RAID, Number of Disks and IOPS

I am trying to understand the optimal number of disks required in a RAID configuration for an application which has been monitored, at peak time, to have the following IOPS. The disk subsystem is ...
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793 views

Hardware RAID controller set to 256kB stripe size, but XFS to 4k block size

Is this configuration ok? I've read that the stripe size should match the block size. I am mostly storing 8-30GB single files that are read sequentially. What should I adjust, and how? Ubuntu ...
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2k views

Perc 5/i and 3TB drives?

Any way to get a Dell Perc 5/i controller to recognize 3TB drives?
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7answers
5k views

Good filesystem for 20TB hardware-controlled RAID5 array?

What's the best file system for Ubuntu 10.10 assuming the average filesize is 8-30GB with no more than 1-2 users accessing the array at any given time?
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Linux software RAID that uses system RAM for write cache

Is it possible to configure software RAID 5 on linux that uses system RAM for write cache? I have a file server with 8GB of RAM ... would be really cool if I could dedicate 4GB to write cache. If ...
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1k views

Damaged Disk with ESXi Data Store needs Recovery

We have a server which has a single 2TB drive in it (it was part way through an upgrade). During this upgrade, the engineer had moved all the Virtual Machines from the main drive set on to this 2TB ...
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135 views

Determining Raid Disk Set

Update Unfortunately looks like the engineer in question had rebuilt the drive we were looking for, and the two sets he thought he had were actually from two completely different machines. I am now ...
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282 views

Mdadm resize not mounting at correct new size

Before, I had four 1TB drives on a RAID array. I added two more 1TB drives to the array, let it do its rebuild and it is not showing the size increase when I mount it. jacks@Gen2:~$ df -h ...
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Dell PowerEdge 1800 Hangs at boot after Dell Cerc Sata RAID Controller Successfully POSTs

Server crashed one night. I rebooted, now it hangs just after the SATA RAID Controller successfully POSTs. This unit has a RAID 5 array, but I haven't pulled a recent enough backup of the data on it ...
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406 views

Restore raid configuration (Ubuntu 8.04 server)

Lost RAID After rebooting AWS, I have lost the RAID (mdadm), while the disks seem to be OK (separately). Symptoms mdadm not working After machine restart (stop and start on Amazon AWS), the device ...
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MegaCLI Media Error Count

This morning, I just got a Nagios alarm because of: BRUBLUst01:/usr/local/bin# /opt/MegaRAID/MegaCli/MegaCli64 -PDList -a0 Adapter #0 Enclosure Device ID: 32 Slot Number: 0 Device Id: 0 Sequence ...
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1answer
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for ZFS: passthru, I-T mode on LSI 9260-8i?

LSI 9260-8i firmware version 2.0x the controller menu does only have RAID: 0, 5, & 6 Solaris ZFS requires passthrough or Initiator-target mode to get direct access to disks.....how to get that ...
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3k views

Is there a list of compatible RAID hardware with standard linux kernel

I am installing a large storage system under Debian 6.0. We bought a HightPont RocketRAID 2720, a very powerfull card claiming to be linux compatible, but when i installed they just provide a already ...
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244 views

How should I arrange partitions/LVs for a 30TB mirror server?

I am planning to upgrade a free software mirror server, and I'd appreciate advice on setting up the new primary disks. My current usage: system software, config and workspace <30GB - stays on ...
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203 views

How to lay out high capacity storage

I'm building high capacity storage for video. It is currently at 20TB mark and keeps growing. Currently, I have 12-bay enclosure filled with 2TB drives and configured in RAID-6. I'm considering to buy ...
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3answers
3k views

Why does mdadm write unusably slow when mounted synchronously?

I have a 6 disk raid6 mdadm array I'd like to benchmark writes to: root@ubuntu:~# cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] md0 : active raid6 sda[0] sdf[5] sde[4] sdd[3] sdc[2] ...
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126 views

Raid 5 fail safe

In a 4 300 GB disk raid 5 setup, the usable space is 900GB. So in the event that one of the hard disk fail, is it that the space available for write will drop to 500GB? It is right to said that in ...
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3k views

How do I replace hard drives in a Dell PowerEdge 1950

My Dell PowerEdge 1950 has 2x 3.5inch 146Gb SAS attached to a PERC 5/I Raid controller card in a raid1 configuration. I want to replace these with 2x 2TB SATA drives which the Dell documentation ...
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4answers
1k views

ESXi 4.1 on separate RAID 10 logical drive or RAID 10 single logical drive

Looked through numerous answers around the varying RAID configurations and the best approach when dealing with ESXi. I still however have some outstanding questions. There are 8x 300GB 10K SAS ...
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mkfs Operation Takes Very Long on Linux Software Raid 5

I've set-up a Linux software raid level 5 consisting of 4 * 2 TB disks. The disk array was created with a 64k stripe size and no other configuration parameters. After the initial rebuild I tried to ...
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3answers
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How do you check the health of individual hard drives in a RAID array?

I'm running a simple 1 TB RAID 1 array with mdadm on Ubuntu Server 10.10. I would like to simply check the status of each hard drive to make sure their both functional before it is too late. How ...
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384 views

Ubuntu raid 1 write errors

I have an Ubuntu server set up with two SATA drives in a RAID 1 configuration with MDADM. The machine is used to record raw video, which involves a lot of writing to the disk. Sometimes during video ...
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869 views

HP ProLiant server - multiple raid controllers?

We just got a brand new HP DL370 G6 server with 14 X 146 gb and 2 X 300 gb sas drives. Inside we got 3 raid controllers (one HP DL370, one HP P410 and one HP P812). It has 2 disk bays and each of them ...
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161 views

Erratic write patterns with linux md RAID1

I'm experiencing strange write performance patterns on a RAID1 array of SATA disks. My kernel is vanilla 2.6.37 and my server has 32G RAM. I'm copying a 32G file from an XFS filesystem on a SAS drive ...
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646 views

Nagios Plugin for Dell Desktop RAID

Is anyone aware of a plugin for Nagios that will report on the status of the RAID controller on dell Workstations, primarily Dell Precision Workstations, T3400 & T3500? I'm currently using this ...
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1k views

RAIDZ vs RAID1+0

Hi guys I just got 4 SSDs for my FreeNAS box. This server is only used to serve a single iSCSI extent to my Citrix XenServer pool and was wondering if I should setup them up in a RAIDZ or a RAID 1+0 ...
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2k views

Email alerts when RAID fails on IBM server?

Have two RAID controllers on an IBM server (X3500 M3) running Windows 2008R2: ServeRAID M5014SAS/SATA Controller LSI Adapter, SAS 3000 series, 4-port with 1064E Can anyone explain how to get email ...
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2answers
3k views

Would you recommend mdadm raid10 for EC2?

I read a blog article somewhere that RAID10 on EC2 cuts down performance by half compared to RAID0. But when you have critical database data on the volumes, how else do you prevent data loss in case ...
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10k views

Proliant RAID 1 Rebuild Questions

I have a HP Proliant ML350 G5 server that experienced a power supply failure overnight. The power supply was replaced but unfortunately it got restarted with only 1 disk in the RAID 1 set plugged in. ...
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HP SmartArray P400 has slow read and write speed

I have desktop in which I installed HP SmartArray P400 controller with two HP DF0146B8052 hard drives. I made RAID0 logical volume from them, but I am getting 20MB/s write speed and ~140-120MB/s read ...
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4answers
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Linux SW Raid: whole disk or per-partition?

I have inherited a machine which has 2 physical disks and uses Linux SW RAID(1). Both disks are partitioned and are are all individual arrays (/dev/md0, /dev/md6, etc.). Those arrays are then mounted ...
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222 views

New hard disks for Xserve RAID

We have an Xserve in our office: MAC OSX 10.4 2 X 2Ghz Dual Core Xeon 2GB RAM It has 4x250GB drives in it and we need to expand. What I am wondering is: Are we limited to what sort of drives we ...
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830 views

cheap storage server: Linux support for RAID on SOHO motherboard chipsets

looking to build a hardware RAID-5 using SATA disks... this will be exposed to a Hypervisor: VMware ESX or Xen but none of the below seem to have driver support on Linux / ESX except AMD SP5100 ...
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164 views

How does RAID compare to secure data against replication?

I am currently trying to figure out the best setup to secure my DB data, but I also have a tight budget. My first (and obvious) solution would be to use replication. But I wonder, apart from problems ...
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SAS vs SSD Performance

Hi does anyone have any input on how a SAS 15k RPM drive would perform compared to a sata based SSD drive, assuming its using the latest verison of sata. These drives would be in a 4 drive raid 10 ...
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3answers
2k views

How do I stop and repair a RAID 5 array that has failed and has I/O pending?

The short version: I have a failed RAID 5 array which has a bunch of processes hung waiting on I/O operations on it; how can I recover from this? The long version: Yesterday I noticed Samba access ...
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617 views

Do all mirrored pairs in a RAID 10 configuration need to be homogeneous in size?

I was planning to expand an existing raid 10 array composed of four 1TB disks with the addition of two 2TB drives. Then I wondered whether, despite the configuration of RAID10 (striping of mirrored ...
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1answer
2k views

Setup options for an HP Storageworks D2600 Array

I have a shiny, new D2600 storage array with 6 x 2TB disks fitted, together with the licence pack that allows me to configure this all as a RAID 6 array. A few questions for you: 1) The array has two ...
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2answers
928 views

Degraded RAID-5 array with lvm2 lost superblock and partition table

I have a RAID-5 array of 4x1TB hard disks with one lvm2 partition on Ubuntu Linux 10.04 LTS. One of the disks has failed. I have re-assembled the array without this failed disk but now mdadm --examine ...
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279 views

What Raid should I use for Website Static Files / Content

I'm building a Web server (IIS7) and would like to know the best practice for storing static content and the uploaded files of website's users (predominantly pictures, but also other documents like ...
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3answers
4k views

btrfs vs. ZFS on a Ubuntu file server

I have a server which is running Ubuntu (Server Edition), and its main job is serving files through FTP (vsftpd) and AFP (netatalk). My /srv directory is starting to fill up, and I need to add more ...
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SAS Expanders vs Direct Attached (SAS)?

I have a storage unit with 2 backplanes. One backplane holds 24 disks, one backplane holds 12 disks. Each backplane is independently connected to a SFF-8087 port (4 channel/12Gbit) to the raid card. ...
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430 views

Get error (Repair Filesystem) 1 # when I install 4 new Hard drives in RedHat Linux 5 on a Dell PowerEdge 2900

I am using a Dell PowerEdge 2900 running RedHat 5. I had 4 drives in the system using RAID 5; I purchased and installed 4 more drives keeping the configuration the same. Set up the Virtual disks in ...
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3k views

ZFS: How can I stop a zpool replace that's currently in progress?

A few days ago, I noticed that the ZFS pool on my home server had started reslivering a disk by itself but was no longer making any progress. The disk had some SMART errors (but did not consider ...
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2answers
1k views

2nd drive in RAID 1 keeps failing

I have a bit of a problem here. I have a Ubuntu Linux server set up with 2 SAS drives in a software RAID 1 (created with mdadm). The RAID will run fine for a day, I can do cat /proc/mdstat and it ...
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3answers
2k views

Removing RAID on a DELL power-edge server

We have a Dell Power-edge T110 server, with either a PERC S100 or S300 raid controller (I suspect S100), and 2 x 500GB SATA hard discs. These discs are running in RAID-1 configuration, (either 1 or 2 ...
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1answer
147 views

Use the exact same type of disk in a RAID, or different manufacturer/batches

What rule do you follow when buying disks for RAID arrays: to buy the disk as similar as possible? to buy the disks from different manufacturers? Some people chose the same type for performance ...
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1k views

Best way to part disks in Linux? (raid, partition or LVM)

There are a few ways to part disks in Linux: raid, partition, and the LVM. How to choose? We have a server with 10+ disks. Some data in our system is temporary and we wish to use RAID 0 on them. ...