RAID - Redundant Array of Independent Disks. A Storage technology to provide redundancy and performance, to reduce I/O bottlenecks involved in using multiple disks for large storage.

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RAID disk lost in just one machine

I have a Blade Center H and a DS4700 SAN. Today we detected one problem in the mail service in one of the blades. It can't see a particular volume available in the SAN. All other blades can see SAN ...
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2answers
654 views

Linux software RAID-1 and device name

I want to set up software RAID-1 on my Ubuntu system, and found this example of an /etc/raidtab: raiddev /dev/md0 raid-level 1 nr-raid-disks 2 nr-spare-disks 0 ...
4
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1answer
554 views

Alternatives to LVM

I was thinking about alternatives to combine several HDDs together. The only options I know so far are using LVM and/or RAID. The thing is, using LVM, I will most probably lose all data, if one ...
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1answer
4k views

Raid 0 Linux Installation fails to install grub

I have a Raid 0 setup (striping) via BIOS not through software raid. When I install linux mint or Ubuntu it fails to install the boot loader or set the boot loader to boot. I get an error stating ...
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6k views

What's the difference between mdadm state “active” and state “clean”

I have two different computers with different RAID5 arrays. When I run the command mdadm --detail /dev/md0 one drive reports "active" while the other reports "clean" for the "state" field. What ...
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1answer
456 views

Migrating from hardware to software RAID

I have an old PCI-X controller running 8 drives in RAID 5. I'd like to dump the controller and go to software RAID under Ubuntu. Is there a way to do this and retain the data from current array? ...
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2answers
144 views

RAID Lag-Behind Burst Write

I would like to setup RAID1 so that a ramdisk in the RAID configuration has occasional synchronisation with a physical disk (that is very battery intensive to run, so I hope to let it spinout). Is ...
4
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1answer
140 views

ext4 directory lists as a file

I'm working with a large (8TB) EXT4 filesystem in linux. After a power outage, the filesystem wouldn't mount. fsck is taking weeks to complete, but i ran testdisk and i'm able to see my partition ...
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207 views

Dual/Triple Booting with dmraid and non-raid disk

I currently have 3 hard drives in my computer The first two disks are in a RAID-1 array, using an Intel P55 chipset, and accessed through dmraid, with the third drive partitioned like so: Filesystem ...
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1answer
2k views

How do I know that a /dev/dm-XX device isn't used by anything on SLES 10.4 (64bit)?

I have a device that I can see in the output of fdisk -l: /dev/dm-XX (XX is a number.) How do I know that I can use this /dev/dm-XX to add it to a RAID1 array? How can I be 100% sure that nothing ...
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1k views

RAID 10 can not be started

I have a RAID 10 array managed with mdadm which has failed . The symptom was that X has crashed and I was unable to logon from the terminal. I have restarted the computer and /dev/md1 did not start. ...
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307 views

Media server RAID difficulties (on FreeNAS)

Disclaimer: I've never used FreeNAS or any type of RAID before, so this is a first. I've decided to build a media server in my new apartment. I'm going to be going with a total 10TB of space (6x2TB ...
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305 views

Software raid checksumming slow

On my new 24 disk array I get 900 MB/s of raw read or write using dd to all the disks. When I set the disks up as a 24 disk RAID6 I get 400 MB/s write and 600 MB/s read. It seems to be due to ...
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3answers
4k views

Mounting multiple devices at a single mount point on Linux

Is there a way to mount multiple hard drives to a single mount point? Let's say I run out of space on /home and decide to add an extra hard drive to the computer. How do I scale the space on a mount ...
5
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1answer
2k views

Linux: LUKS and multiple hard drives

I have a Debian Linux system (amd64) installed on a RAID-1 system encrypted device (LVM on LUKS) and will have a RAID-6 of >=4 disks where I'll put my data (LUKS and maybe LVM). I think the basic ...
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2answers
624 views

Software raid + separate partitions?

I have setup software RAID1-arrays using two 250GB harddrives. There's two arrays - one named md0 in which the system is kept and the other, md1 works as swap: # cat /proc/mdstat md0 : active raid1 ...
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3answers
35k views

How to check mdadm raids while running?

I'm starting to get a collection of computers at home and to support them I have my "server" linux box running a raid array. Its currently mdadm raid1, going to raid5 once I have more drives (and ...
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1answer
2k views

Why does btrfs allow to create a raid1 with mismatched drives?

I'm creating a btrfs using sudo mkfs.btrfs -m raid1 -d raid1 <small-disk> <large-disk> or sudo mkfs.btrfs -m raid1 -d raid1 <large-disk> <small-disk> it creates the fs with ...
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1answer
1k views

Interpreting tiobench results

I'm running tiobench on my raid1 and it gives me the following results. Why is there ##### shown instead of throughput? Why does seq.reading with 8 threads use 2836% CPU? My results: $tiobench No ...
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1answer
277 views

Raid5, what could happen? Partition corruption, now what do I do?

First, I probably deserve this for not having a backup. My system was installed with Debian and Mint11. I recently installed Mint12 to play with. I expected all three to continue to work. I can no ...
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2answers
129 views

View Files from mirrored RAID outside the device

The Product I have is a Western Digital My Book The device has stopped working but there is nothing wrong with either of the two mirrored drives. I would like to take out the two mirrored hard ...
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3answers
1k views

Is creating a sparse image using dd appropriate for backup/restore from a RAID?

I have two non-networked servers, each with 1.2TB of storage in a RAID5 config on an LSI MegaRaid 9240-8i controller. I have been trying without success to get Symantec Ghost to image one machine to ...
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3answers
1k views

Avoid pause during dm-raid initialization

On my CentOS 5 workstation I get a few seconds wait after dm-raid45 has been loaded ("Initializing Driver" or something like that). This seems to be part of the initrd. After that the system boots ...
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3answers
4k views

Using mdam --examine to write mdadm.conf

I'm trying to script the RAID setup for a (growing) number of identical servers. The advice I've seen for using mdadm suggests that once the RAID array has been created you can run mdadm --examine ...
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1answer
325 views

is it possible to recover a raid 5 array by using usb enclosures?

I had a RAID 5 (Linux software RAID) server which recently decided not to boot anymore. It seems to be a motherboard problem possibly due to not being protected by a UPS during a power failure. It ...
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2answers
280 views

Copying linux install from non-RAID/x86 to RAID/x86-64

I'm copying an Ubuntu Server install from an x86 machine with a single hard disk to a new machine with x64 and two identical disks. Two partitions will span the new disks: One small-ish RAID1 for ...
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2answers
147 views

Move Web Directory to Raid Array

I want to improve the performance of a web application running on Apache, so I created a Raid Array on /dev/md0. Now I need to figure out how to move the application to the array and make sure that ...
2
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1answer
120 views

Rosewill RC-212 and Fedora 15

I recently bought a Rosewill RC-212 and configured it in the BIOS for RAID0. Windows 7 recognizes the array without any extra drivers and installed to it without problems. I installed Fedora 15 on a ...
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3answers
267 views

Get Position of RAID Hard Drives

I was recently tasked with creating a hard drive management system on Linux. I needed to write a program that monitored when drives came online and offline and created/removed links to the drive ...
2
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1answer
411 views

curious soft raid 5 setting inconsistency

Lately I bit the bullet and upgrade my OS from Fedora 11 to Fedora 15, and I've been trying very hard to figure out why Fedora 15 can't see the Raid setup that I created in Fedora 11. I think I must ...
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3answers
2k views

Linux + how to verify mirror configuration on linux red-hat

I have an IBM blade server and we've installed RedHat Linux on the machine. How can we check if we have both disks running as a mirror, or if everything is only running on a single disk? What ...
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713 views

Linux Mint installer does not see fakeraid drive

I have a computer with a fakeraid 0 array (the computer came with it, and I don't want to remove my other OS to get rid of it), and I am trying to install Linux Mint. When I first boot up from the ...
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443 views

Intel Z68 chipset raid5 disappeared

I have this motherboard, it's a gigabyte Intel Z68 chipset. I used the Intel chipset configuration (between BIOS and OS) to configure a 3 disk Raid5 array which I formatted as NTFS (Linux already has ...
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6answers
3k views

Pros and cons of software Parity-RAID (e.g. RAID5)

I was recently told about some problems concerning Parity-RAIDs without a non-volatile cache. More exspensive HW-controllers do have battery-powered caches to finish write-operations in case of power ...
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2answers
995 views

Choosing filesystem for a 16TB Raid

I'm just putting together a machine with eight 2TB disks. I will be using Raid 6 (12TB of usable capacity) on top of them, but I'm not sure whether I should make LVM on top of the RAID, or what ...
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1answer
513 views

In my Dell R310 server, i would like to install CentOS, but for RAID1 what special care i need?

I have my Dell R310 server to install CentOS latest version, it has 2 hot plug disk drive, about 250GB of each. - But i need to install RAID1 on it. My question is for RAID1 installation with ...
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0answers
248 views

Using device node of host bus adapter to send ioctl calls to monitor RAID status

I am interested in determining the status of a RAID array on my system (using Debian, and Intel ICH10R sata RAID controller = fakeRAID). What I have learned so far is that: I can use CSMI I/O ...
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5answers
936 views

Consumer Level software RAID5 and LVM

Hi I am going to build a 6 drive consumer level RAID 5 (10TB) with Ubuntu10.10 and using EXT4 as filesystem, and OS on another drive. Question: Should you use LVM on top of the RAID5 or should just ...
6
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1answer
2k views

mdadm Raid5 gives spares missing events

I succesfully builded up a raid5 array on debian testing (Wheezy). As the manpages and further tell, the array would be created as an out of sync array with just a new spare injected to be repaired. ...
0
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1answer
209 views

If there's no /dev/md* and not /proc/mdstat, is it safe to use a second disk as a second disk?

There's two HDs in this server. I don't see an md device (see title) or an mdstat file. So, can I be safe that the second disk is currently unused? Yes, I do want/need the second disk as space much ...
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3answers
371 views

What would be a good choice for an elastic file system (for adding storage at a later date)?

I'm currently running a Debian 6.0 server with EXT3, but I'd like to move over to Arch. It's being used as a file server right now with a 1TB drive in it (of which 650GB in it is used). What I'd like ...
6
votes
2answers
2k views

Will the system make sure that mdadm is sync-ed before completing a reboot?

This is a follow up to my crazy mdadm problem. I'm trying to figure out what might have caused sda to get out of sync in the first place. The only thing I can think of is that I had just run a bunch ...
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1answer
1k views

installing grub 2 on mdadm, which device?

when installing grub(2) to mdadm devices are you supposed to install it to /dev/sdX or /dev/mdX?
2
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1answer
364 views

Drive was unable to assemble into the array

I ran mdadm -A /dev/md0 /dev/sda1 /dev/sdb1 Only /dev/sdb1 was loaded into the array though. I have a few more arrays on the same two drives too. Each time the partition on sda failed. dmesg told ...
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2answers
546 views

In place upgrade of a software raid 5 array

I run a software raid array for my backups, but my data has outgrown capacity. considering I have a full 2.4TB array with 5*600GB drives and also have 5*2TB drives I would like to swap in. What ...
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2answers
404 views

Is their a 'friction free' way to convert RAID1 to RAID5?

What's the best way to convert Linux software RAID 1 array to RAID 5? ( I have already bought the 3rd Hard Disc !)