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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Do I need a second RAID controller for fault-tolerance?

I have a server with 3 hard drives installed, and a total capacity of 6. We're planning to max it out, but our consultant also suggested getting a second RAID controller "for redundancy" to support ...
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748 views

RAID array Considerations - Any advice?

We just bought a Dell PowerEdge r510 (12 drive bays) that will fill the role of an archive server. We have 6 drives (1TB each) installed. The plan is to have all the drives in a single RAID array and ...
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Poor read performance on Dell Perc H200 RAID10 with (4) 1TB 7200rpm 64MB drives

I am seeing only 50MB/s reads: ensnare@box:~$ sudo hdparm -tT /dev/sda [sudo] password for ensnare: /dev/sda: Timing cached reads: 4592 MB in 2.00 seconds = 2296.48 MB/sec Timing buffered disk ...
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How to find RAID configuration/level and RPM speed having only remote access to the server?

Having only remote access (no physical access), to a server (that is SSH), how do I (or may be is it possible): find out whether it is RAID configured or not? If it is RAID configured, whether it ...
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Can I create a “soft” RAID1 array without nuking data?

I've just bought two 1.5TB disks with the aim of creating a 1.5TB RAID1 array. In my infinite lack of wisdom (and a lack of space inside the computer - it already had 6 disks), I stuck one in, ...
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What does 3Ware's tw_cli mean by a “DEGRADED” disk vs “ECC-ERROR”?

I've got a sad RAID array on a 3ware 9650SE-16ML card. What I can't tell is if I've just suffered a double-disk failure (bummer!) or if I'm reading this wrong. The relavent output of /c0 show all ...
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How do I recover from a faulted zpool where one device is OK, but was temporarily offline?

I have a zpool with 4 2TB USB disks in a raidz config: [root@chef /mnt/Chef]# zpool status farcryz1 pool: farcryz1 state: ONLINE scrub: none requested config: NAME STATE READ ...
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144 views

How do I troubleshoot my RAID array?

I just checked into my RAID array this morning and what I got is: $ cat /proc/mdstat Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10] md1 : active raid1 sdc7[0] ...
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How do you connect more than 4 drives to a LSI 9361-4i MegaRAID controller?

I’m fairly new to proper hardware RAID having only used it in pre-built server machines before, but on the recommendation of some friends who work for datacentres I’ve bought an LSI 9361-4i MegaRAID ...
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973 views

For a server that can tolerate downtime, is it better to use a hot spare or a cold spare?

In other words, should I leave a spare disk on the shelf or set it up as a hot spare? If the server has a little bit of downtime, it isn't the end of the world. It's not a webserver or anything that ...
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2answers
459 views

Are different RAID cards setups compatible?

I'm setting up a new NAS/SAN system with RAID5, and I was wondering if going the software or hardware RAID way because I had this question in mind: If my hardware-RAID card fails, will I need to ...
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5answers
29k views

kernel: journal commit I/O error

I am having some problems with a Dell 1950 server. I am installing RHEL 4.6 along with Oracle and some other software on here. I am randomly getting an error message saying "kernel: journal commit ...
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2answers
673 views

convert 1x2TB HDD with LVM into 2x2TB HDD with RAID1+LVM or with LVM mirroring?

I have Ubuntu server with 1x2TB HDD and 1x128GB SSD (unused). There are 2 partitions: /boot, and a physical volume for LVM, which has 1 group and 5 logical volumes: /, /var/log, /home, /srv, /tmp. ...
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734 views

growing a raid z(1/2)

I'm planning on building a fileserver on top of opensolaris, using either a raid z1 or z2. Is it possible to later upgrade a disk at a time and immediately have access to the increased storage? Or ...
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1answer
18k views

Can Windows 7 do software RAID 10 (1+0)

Can Windows 7 do software RAID 10 (or RAID 1+0 depending on terminology)? There appears to be a lack of information about software RAID for Microsoft Windows products. Even a search of the ...
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Raid 1/10: Kernel panic- not syncing: attempted to kill init

I have setup Raid 1 & Raid 10 in Virtual Box for learning purpose. The following Partitions for 4 Hard Drives: I make a 100mb partition (/boot) on four drives and make that a raid 1 partition. ...
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2answers
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Boot from software RAID 1 on Windows Server 2008 R2

I have a Windows Server 2008 R2 x64 system with a single hard drive, and I have a spare hard drive of same size/model that's not being used. I was thinking about dropping in the new drive and setting ...
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1answer
3k views

How to select the best Stripe Size when configuring a RAID Array

There are various "references" on the Internet that delve into some discussion about what factors to consider when selecting a particular RAID stripe size (4KB to 128KB or more) for an array of disks, ...
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LSI 9285-8e and Supermicro SC837E26-RJBOD1 duplicate enclosure ID and slot numbers

I am working with 2 x Supermicro SC837E26-RJBOD1 chassis connected to a single LSI 9285-8e card in a Supermicro 1U host. There are 28 drives in each chassis for a total of 56 drives in 28 RAID1 ...
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764 views

Which block sizes for millions of small files

I have 2x 4TB Disks in hardware RAID1 (it might be a LSI MegaRaid) on Debian Wheezy. The physical block size is 4kB. I'm going to store 150-200 million of small files (between 3 and 10kB). I'm not ...
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Will spinning down hard disks create Linux Raid problems?

I'm setting up a server that will need to be accessible 24/7 but will be rarely accessed (archive storage). To save heat/power, I'm thinking of setting hard disks to spin down using hdparm. However, ...
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362 views

RAID with 4 drives offers very minimal speed improvement

Setup 1.5TB x 8 on a SANS Digital enclosure configured into two sets of 4 drives and connected to a Windows Server 2003 computer over eSATA. They are all identical Seagate Barracuda ST31500341AS ...
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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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RAID strategy - 8 1TB drives

I'm setting up a backup storage device- This machine has Windows Server 2008, on a separate boot drive. It has 8x 1TB drives, and uses a hardware RAID card. My question is, which RAID configuration ...
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11answers
24k views

Most efficient RAID configuration with 6 disks?

I have a hand-me-down server that I'm setting up at home and it's got 6 72Gb hard disks (as well as 2 18Gb drives that I'm using for the OS). What is the best way to configure those 6 drives? Should ...
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7answers
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Use of 2.5" Laptop Drives in a Server?

We're acquiring several 1U servers with (8) 2.5" drive slots. Although we can use either SATA or SAS, there is a large price variance as soon as you order 16 or 24 of these drives, so we are looking ...
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4answers
298 views

Why are there RAID models where there are more than one parity disk?

I was just wondering how multiple "parity disks" would work, since it seems that doing so might defeat the purpose of having a parity.
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8answers
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24TB RAID 6 configuration

I am in charge of a new website in a niche industry that stores lots of data (10+ TB per client, growing to 2 or 3 clients soon). We are considering ordering about $5000 worth of 3TB drives (10 in a ...
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RAID 0 recovery

I know the theoretical answer is "not possible". But theory and practice do not always match. So I'm wondering if you know any trick to recover something... Is there any chance to recover anything ...
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750 views

RAID with three disks (RAID 5 vs RAID 1E)

I am upgrading a server which has four drive bays. I'll be putting a new Adaptec RAID card into the server so it will support large drive sizes. I need to squeeze as much capacity as possible out of ...
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4answers
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howto plan RAID for ESX

eight 300GB SAS drives are available. Can ESX be put on one disk as RAID-0 and others as RAID-5 ? so that in the event of disk failure data (VMs) are safe. if os disk RAID-0 fails could that be ...
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How do I configure RAID 5, especially stripe size, with 24 x 1.2 TB drives for CentOS 6?

For a Dell R920 with 24 x 1.2TB disks (and 1TB RAM), I'm looking to set up a RAID 5 configuration for fast IO. The server will be used to host KVM VMs that will be reading/writing files of all sizes, ...
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ZFS on top of Hardware Mirroring, or just mirror in ZFS?

I have an IBM x346 with dual 3.2Ghz Xeons and 2x36GB 15k SCSI disks. I'm running an entirely ZFS-based install of FreeBSD 8.1. I can configure the bios to mirror the two disks, and then put ZFS on ...
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3answers
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What is the difference between a HBA card and a RAID card?

I thought I knew the difference between HBA and RAID. In my mind, HBA is offloading from the main motherboard/CPU and is simply JBOD... usually has an external SAS ports, whilst a RAID card does the ...
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2answers
513 views

Is SAFE new terminology that is replacing RAID? [closed]

I was looking for an external drive enclosure with a RAID controller and found one in Newegg. Looking at Wikipedia, I cannot find information on this "SAFE" terminology. Is this a replacement for ...
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Moving a RAID array from one machine to another

I'm not too familiar with RAID arrays, but I plan on making a RAID 5 array for a fileserver. However, once I get the RAID running for a while, I have plans to move it to another machine (with ...
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5answers
4k views

RAID level confusion (MegaCli vs megasasctl output)

I'm utterly new to working with LSI MegaRAID controllers and I'm confused as to what RAID level I am actually running. My server is equipped with 4 disks, 4TB each and I would like to have them ...
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6answers
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SQL Server Transaction Log RAID

We have three SQL Server servers, and each server has a about five or six databases on it. We are in the process of moving these servers to a new SAN and I am working on the best RAID configuration. ...
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5answers
4k views

SW SSD Raid 1 over HW RAID 10

A provider(data center) recommended I go with 1TB SSDs in a software RAID 1 over HW RAID 10 with mechanical drives. Their quote: Typically SSDs are most reliable than RAID cards and since you ...
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2answers
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Does adding more drives to a RAID 10 Array increase performance?

I'd like to know if I were to add additional drives to an existing Raid 10 if this would increase the speed of the entire array?
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5answers
39k views

RAID 6 vs RAID 10? Which would you choose

My choice would be RAID 6 for a file server since you can lose two drives and it does not matter which set of two can die. From what I understand with RAID 10 you can lose two drives but if they ...
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Upgrading RAID controller to 4kn - do I have to reinitialize the array to use 4kn?

I have an enterprise-grade workstation with an Adaptec 6405E RAID controller in it. According to Adaptec, this RAID controller does not, and will never be able to, natively support 4K disk sectors. If ...
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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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1answer
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Does ZFS replace the need for hardware/software RAID?

I want to provide protection against data loss on my servers. Typically, I'd use hardware RAID 1 or 5, but I've been reading up on ZFS. Is it correct that ZFS itself provides RAID 1 or 5 like data ...
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2answers
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Dell Perc 6/i and 3TB drives?

Does the dell Perc 6/i controller support 3TB drives?
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5answers
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What is the best way to configure 6 disk raid for SQL Server + OS?

I'm setting up a SQL Server on Win 2k8 with following hardware: 6 x WD RE3 500G SATA PERC H700 I've read some suggested that putting log file and OS on its own RAID1 while the rest of data is on ...
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3answers
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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
819 views

Would unplugging a drive simulate a drive failure?

I just set up a RAID 1 array, 2 2tb drives mirrored. I am wondering what will happen if one were to fail. Would unplugging one of them be a valid test? I am using the Onboard controller of an asus ...
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How long should rebuilding 250GB take? [closed]

In a PowerEdge 1900 have I a hardware RAID 5 of 5x250GB disks + 1 hot spare 250GB. Disk 2 have errors, so I forced it offline in the raid bios to replace it. Now it have been rebuilding to the hot ...
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485 views

mdadm: Replacing array with entirely new drives

I have a server with three 500GB drives, with most of my data in a RAID5 configuration spanning the three of them. I just purchased and installed four 1TB drives, and the intention is to move off of ...