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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How to monitor the hard disk status behind Dell PERC H710 Raid Controller with CentOS 6?

I have a Dell server running CentOS 6 using PERC H710 Raid Controller card with Raid 5 setup and I want to monitor the hard disk failure/working status behind the Raid Controller. Then I should be ...
11
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2answers
2k views

What counts as a 'large' raid 5 array?

A recent issue with a Buffalo TeraStation NAS here in my office has got me investigating Raid 5. I've found a few different articles talking about the unsuitability of using raid 5 in large arrays, ...
11
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3answers
203 views

If RAID5/6 are risky due to URE, are full backup/restore schemes at risk too?

As I understand it, you have a high chance of encountering an URE during a rebuild due to having to read a large amount of data to perform the task. Does this problem also affect backup and restore ...
11
votes
8answers
33k views

Guidelines for the maximum number of disks in a RAID set?

In any of the RAID levels that use striping, increasing the number of physical disks usually increases performance, but also increase the chance of any one disk in the set failing. I have this idea ...
11
votes
4answers
941 views

SQL Server setup check list

What are the things I have to consider when I have to install SQL Server (2005/2008) on a new server? Storage setup TempDB Security What are some common mistakes made in that process?
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3answers
15k views

How do I rename an mdadm raid array?

I have assembled a new raid array to replace an old one. However, this new array got assigned an automatic name of /dev/md127 and I want to rename it to /dev/md3, so that I don't have to change ...
11
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1answer
7k views

Managing battery relearn cycles on LSI and similar RAID controllers

How do engineers deal with RAID controller battery "relearn" cycles? As noted in: What's a "battery relearn" on a LSI MegaRaid?, relearn cycle discharges the RAID controller battery (...
11
votes
6answers
978 views

How to utilize spare workstation drive space for server storage/backup

So, given the fact that you can only get hard drives of about 160GB now for the cheapest price, I find i have a ton of extra drive space on workstations spread throughout my office. I'd like to ...
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12answers
2k views

How to remember RAID levels? [duplicate]

How do you remember(if you really do :-)) all the different levels and what each level does? Can anyone suggest an easy way to remember?
10
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7answers
732 views

Can a RAID 4 disk setup crash if only 1 hard disk fails? [closed]

I am a web developer. I have not much experience in hardware. For this reason, I use managed servers. This morning, one of the drives in our setup failed. However, the full site went down. I ...
10
votes
2answers
8k views

How to upgrade a ZFS RAID-Z array to larger disks on OpenSolaris?

I'm planning on installing OpenSolaris on my home server (right now it has Linux) and I would like to know how to prepare for upgrading the server to have larger hard drives in the future. Now the ...
10
votes
2answers
22k views

How exactly does a SAS SFF-8087 breakout cable work? + RAID/connection questions

Please let me know if my question does not makes any sense as I am not sure if I am interpreting it correctly from my thoughts due to my lack of technical knowledge on this. If I am using a ...
10
votes
3answers
10k views

Is a large RAID-Z array just as bad as a large RAID-5 array?

For a long time I've heard about how bad an idea a large (>5TB?) RAID-5 array is simply because there's a high risk for another drive to fail. Has RAID-Z1 managed to remedy this for an array of any ...
10
votes
3answers
20k views

Can we mount multiple disks as one directory?

Are there way to mount the different disks as one directory? Assuming I have some disks with ext4 partitions: /dev/sda1 1Tb mounted as /store1 /dev/sda2 2Tb mounted as /store2 /dev/sdb1 2Tb mounted ...
10
votes
3answers
11k views

Battery Backed Write Cache

I recently got some U server price quotes and some of them include BBWC: What exactly does it do? Is it just for RAID configurations? If there is a power malfunction, isn't the data loss ...
10
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2answers
2k views

Are consumer class hard disks okay for zfs?

I just recently bought a new server an HP DL380 G6. I replaced the stock smart array p410 controller with an LSI 9211-8i. My plan is use ZFS as the underlying storage for XEN which will run on the ...
10
votes
2answers
2k views

Why is my RAID1 read access slower than write access?

I have done some simple performance tests and it seems that reading from my RAID1 is slower than writing: root@dss0:~# for i in 1 2 3; do dd if=/dev/zero of=/dev/sda bs=1048576 count=131072; done ...
10
votes
7answers
4k views

Hot spare or extra parity drive in RAID array?

In a different question about configuring a RAID array, the author is building a RAID array with 8 drives. One answer suggests using 7 drives in RAID 5 with one left over as a hot spare. Since RAID 6 ...
10
votes
5answers
16k views

How do you monitor the health of a mirrored disk in Windows?

I have a Mirrored Dynamic disk on my Windows 2003 Server. How do you monitor the health of the volume? Is there a way to have the server send an email when there is an issue with the volume? Is there ...
10
votes
1answer
7k views

Easy to expand Linux software RAID 5 with XFS. Best practices?

I use my Ubuntu machine as a file server for Windows/Linux/Mac clients using a Samba share. I need it to be easily expandable by just adding more hard drives without having to move any data back and ...
10
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2answers
1k views

Areca 1280ml RAID6 volume set failed

Today we hit some kind of worst case scenario and are open to any kind of good ideas. Here is our problem: We are using several dedicated storage servers to host our virtual machines. Before I ...
9
votes
3answers
9k views

explain md's raid10,f2

I know how most of the various RAID's work. But I stumbled on the recommended raid10,f2 mode while researching linux software raid. I don't really understand how it works on 2 or 3 disks. could ...
9
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2answers
38k views

What is the fastest and safest RAID combination for SATA drives?

I wonder what is the fastest and safest RAID combination for SATA drives and general use (some write, mostly read)? RAID 0 is fast but utterly unsafe, RAID 1 is safe but slow, RAID 5 is safe but not ...
9
votes
6answers
8k views

ZFS Like Alternatives on Windows

Conceptually, and I don't think I am alone here, I love the concepts of ZFS. You can create one big disk, everything is stored on multiple drives, and you can grow and shrink the pool and drive at ...
9
votes
4answers
119k views

How to check if hardware RAID is configured?

I have several servers running Windows 2008 and Red Hat 5 that are capable of hardware RAID. How do I check that hardware RAID is configured?
9
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4answers
964 views

Do disks in Raid-1 function outside of the raid?

Raid-1 is mirroring two disks (if I haven't messed up completely here :p). Does that mean that I could take one disk out and put it into another machine and it would work like a normal disk? Or does ...
9
votes
2answers
17k views

Megacli is killing me, any help appreciated

I run a server with 2 drives in raid0 configured through BIOS. I just added 2 more drives using hotplug (the server is dell r610 with RHEL 5.4 64bit) and I would like to configure a separate raid0 ...
9
votes
3answers
2k views

Best practice for 24 Disk Array

we have just migrated for our old fibre SAN storage to an IBM v3700 storwize with 24 SAS 600GB disks. This storage is connected directly to two IBM ESXi 5.5 servers each with two 6Gbps multipath SAS ...
9
votes
5answers
5k views

Squid or Other HTTP Caches with SSD Cache Store?

I'm contemplating setting up a squid (or possibly varnish) cache on a system with SSD drives. The obvious benefit is that these systems have great READ speeds and I expect my hit ratios to be fairly ...
9
votes
1answer
1k views

Why does df shows only half the size of a RAID10 array?

I've created a RAID10 array using 4 75G drives, to create a storage of 150G. After everything finished (including the initial syncing), everything looked good except the output of df -h which showed ...
9
votes
2answers
1k views

How to check CentOS 6 Server VM Host after a power falure?

This afternoon, someone at our office decided to pull the plug out of our server because it was storming outside. They didn't shut it down, they just pulled the plug out while it was running. The ...
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3answers
2k views

Linux fileserver storage pool

Is it possible to get linux server to share several hard drives as one storage pool through Samba? So that when I use the share I don't have to worry about saving to a certain drive that has free ...
8
votes
3answers
1k views

Is it safe to write data to a RAID 6 while it's rebuilding?

I have a test RAID controller on my network which hosts a very large RAID 6 (11 drives, 3TB each). One of the drives failed, and the array is now rebuilding. At this rate, I think it will take about 3 ...
8
votes
4answers
25k views

Why do I need a raid battery pack?

I'm trying to understand why one would add a batterypack to a raid card. It seems to me like if power goes down, running just the raid card is going to do little good: without power for HDs and ...
8
votes
5answers
30k views

Disabling RAID feature on HP Smart Array P400

I'm planning to use ZFS on my system (HP ML370 G5, Smart Array P400, 8 SAS disk). I want ZFS to manage all disks individually, so it can utilize better scheduling (i.e. I want to use software RAID ...
8
votes
2answers
6k views

Can different drive speeds and sizes be used in a hardware RAID configuration w/o affecting performance?

Specifically, I have a RAID 1 array configuration with two 500gb 7200rpm SATA drives mirrored as logical drive 1 (a) and two of the same mirrored as logical drive 2 (b). I'd like to add two 1tb ...
8
votes
1answer
2k views

FREENAS: Why isn't mv command instant within a RAIDZ1 volume?

I'm currently 'reorganizing' file structure within a RAIDZ1 volume. Moving directories from one dataset to another, which are both contained on the same volume. SSH'ed into the machine and did a ...
8
votes
4answers
5k views

One large RAID 10 vs several smaller arrays?

My question is: when is it appropriate to simply create one large array with fast read & write performance, such as RAID 10, instead of creating smaller arrays for specific applications? It ...
8
votes
3answers
1k views

Migrate raw disk image over LAN

Here is my situation: Two dedicated servers in the same datacenter with gigabit ethernet between them. Both dedicated servers booted into a rescue environment based on Debian Squeeze with extra ...
8
votes
1answer
5k views

mdadm and 4k sectors (advanced format)

There are numerous questions on Serverfault about aligning 4k sectors disks, but one thing is not really clear to me yet. I successfully aligned my RAID1+LVM. One of the things I did was use mdadm ...
8
votes
2answers
989 views

Windows Server Backup Error - Volumes Larger than 16.7TB cannot be protected?

I'm trying to use Windows Server Backup to backup a RAID array on my new server. But, when I do, I run into this error: The server is running Windows Server 2012 R2 and the array in question is ...
8
votes
8answers
16k views

How to Monitor an Adaptec/Intel ICH10R RAID Controller (any SNMP notification options?)

SuperMicro's Super Doctor III is the software I was looking for. It is SuperMicro's equivalent of IBM's ServerGuide or Dell's OpenManage. Unfortunately, while it supports hardware monitoring and SNMP ...
8
votes
3answers
3k views

Restoring an Amazon EBS RAID0 array from snapshots taken with ec2-consistent-snapshot

I've configured a new MySQL server on Amazon EC2 and decided to store my data on a EBS RAID0 Array. So far so good, and I've tested taking snapshots of those devices with ec2-consistent-snapshot, ...
8
votes
1answer
13k views

Ubuntu server, gpt partition table, mdadm, grub boot fail

Basic working system details: I used the Ubuntu 12.04 server CD to install a server. I have 4 disks. On all disks I did the following, similar to this howto : created a 2GB swap partition created ...
8
votes
2answers
1k views

Linux RAID-0 performance doesn't scale up over 1 GB/s

I have trouble getting the max throughput out of my setup. The hardware is as follow : dual Quad-Core AMD Opteron(tm) Processor 2376 16 GB DDR2 ECC RAM dual Adaptec 52245 RAID controllers 48 1 TB ...
8
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2answers
1k views

How to attach an existing RAID1 to a fresh Linux system?

I have a RAID1 currently operating on a single hard drive (yes, the mirror is absent). Is it possible to reorganize my system using the following algorithm? I set up another single-disk RAID1 (onto ...
8
votes
3answers
12k views

How to resize RAID1 array with mdadm?

I've running Ubuntu 11.04 (kernel 2.6.38-11). I replaced 2x160GB with 2x500GB drives. They are configured as RAID1. The partition tables show the right sizes. Here's sfdisk: # sfdisk -d /dev/sdb # ...
8
votes
1answer
2k views

Can I use dmraid instead of md (mdadm) to make software RAID-1 and RAID-1+0 volumes?

On a related question about SSDs and TRIM (see: Possible to get SSD TRIM (discard) working on ext4 + LVM + software RAID in Linux? ), it turns out that dmraid may now (or shortly) support TRIM on RAID-...
8
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2answers
1k views

Linux Software Raid 10 hung after 1 drive failed, mdadm will not let me force remove the faulty device

I have a Linux software raid 10 setup consisting of 5 RAID 1s (Two drives per mirrored setup) and a RAID 0 across all 5 RAID 1 pairs. To test that none of the drives were going to fail quickly under ...
7
votes
7answers
10k views

Can I just remove a disk from a live RAID 1 array?

I've read the story about the manager taking out a disk from a RAID 5 array, and then a second one, but I’d just like to try out for myself what happens when I simply disconnect a disk from a live ...