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Questions tagged [software-raid]

RAID solution handled by the operating system.

Software RAID is implemented in the OS. It uses CPU to handle the RAID setup. It is cheaper than hardware raid. It often doesn't support features which you can find with hardware raid like:

  • hot spare
  • fast rebuilding of an array
  • hot swapping
  • high write throughput

Another problem is that it uses the CPU and memory of the computer to perform all the tasks (hardware raidcards have a special cpu and memory for this task). Therefor generating more load on your system.

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What is better LVM on RAID or RAID on LVM?

I currently have LVM on software RAID, but I'd like to ask you what you think it is better solution, maybe some pros and cons? Edit: It is about software raid on lvm or lvm on software raid. I know than hardware raid is better if we are thinking…
Ency
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How to interrupt software raid resync?

I want to interrupt a running resync operation on a debian squeeze software raid. (This is the regular scheduled compare resync. The raid array is still clean in such a case. Do not confuse this with a rebuild after a disk failed and was…
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RAID - software vs. hardware

I have always used hardware based RAID because it (IMHO) is on the right level (feel free to dispute this), and because OS failures are more common to me than hardware issues. Thus if the OS fails the RAID is gone and so is the data, whereas - on a…
Robert MacLean
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How do I tell if grub is installed on a device?

How can I tell if grub is installed on a disk, and if it is what settings it has (noteably, what it has for the root parameter) I need to check a lot of disks in software RAID1 arrays to make sure both disks have grub installed, with the grub on…
DrStalker
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Readahead Settings for LVM, Device-Mapper, Software Raid and Block Devices - what wins?

I've been trying to find a straight answer on this one, and it has proved elusive. This question and its answer is close, but does not really give me the specifics I would like. Let's start with what I think I know. If you have a standard block…
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How beneficial are self-healing filesystems for general usage?

I have recently looked into advanced filesystems (Btrfs, ZFS) for data redundancy and availability and got interested in the additional functionality they provide, especially their "self-healing" capabilities against data corruption. However, I…
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Why is RAID 0 classed as RAID when it's not redundant?

I've worked in IT quite a number of years, so I know what a RAID array is, what RAID 0 is, RAID 1, 5, 6, 10, 50, 60, etc., but something sprung to mind in a recent conversation at work; if RAID stands for redundant array of independent (or…
Gavin Burke
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How to view status of software RAID 1 resynching?

I have two 500 GB disks and yesterday I mirrored first drive to the second one using software RAID 1. PC has now been on for 30 hours. Both disks say "Resynching", but there is no progress indicator. In addition, there is a small yellow exclamation…
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How do I move a Linux software RAID to a new machine?

I have a newly built machine with a fresh Gentoo Linux install and a software RAID 5 array from another machine (4 IDE disks connected to off-board PCI controllers). I've successfully moved the controllers to the new machine; the drives are detected…
romandas
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Best way to grow Linux software RAID 1 to RAID 10

mdadm does not seem to support growing an array from level 1 to level 10. I have two disks in RAID 1. I want to add two new disks and convert the array to a four disk RAID 10 array. My current strategy: Make good backup. Create a degraded 4 disk…
Hans Malherbe
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Sanity check on 40TB server configuration

I've got 40 years in computing, but I've never had to build a server quite like this one, so this might be a n00b question. I have a client that is going to offer ultra-high def music files for download. In this case that means FLAC-compressed…
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Can you change the metadata version on an existing array?

So grub requires metadata version 0.90 I'm wondering if I can change my existing arrays to use that instead of the default which is 1.2. That way I don't have to go about a reinstall. If yes, how can I do it?
xenoterracide
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Device: /dev/sda [SAT], 1 Currently unreadable (pending) sectors

I have a software RAID 1 array on RHEL. I am getting this error emailed to me each morning: Device: /dev/sda [SAT], 1 Currently unreadable (pending) sectors When I run a test on sda (or sdb) everything appears to pass. Am I missing…
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How do I list which drives are part of each RAID array?

I have a linux software RAID using md. I want to list all of my RAID arrays and each hard drive attached to them. Is there an easy way to do that?
fatal_error
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High server load - [jbd2/md1-8] using 99.99% IO

I've been having spike in load over the last week. This usually occurs once or twice a day. I've managed to identify from iotop that [jbd2/md1-8] is using 99.99 % IO. During the high load times there is no high traffic to the server. Server specs…
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