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On Saturday 06 May 2006 15:47, Neil Stone <neil@×××××××××××.com> wrote |
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about 'Re: [gentoo-amd64] How to install to a RAID set?': |
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> Now here is a thing, is it possible to build gentoo form the ground up |
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> on a software RAID config.. i am pondering purchasing a gentoo server, |
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> but i figure theres no point is it won't play from the word go. |
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There's two types of SW RAID in the kernel. One is standard, pure |
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software, md-raid which can be maintained using raidtools (old and busted) |
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or mdadm (new hotness). I'm using this to run RAID 0 across two raptors. |
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Upsides include ease of configuration and hardware independence. |
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Downsides include (in practice) OS (Linux) dependence. |
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|
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Then, there is the "firmware" raid. The raid configuration is stored in |
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hardware but all the actual /work/ is done in software. Downsides include |
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difficultly configuring, hardware dependence, and generally flakey |
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implementation -- on both the firmware and Linux sides. Upsides include |
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(some) OS-independence. |
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|
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Both are supported by Gentoo, but like most things Gentoo you will need to |
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get in and configure stuff yourself, mostly using the tools provided by |
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upstream. While I know my way around mdadm and lvm fairly well and could |
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help you there (they are simple tools anyway), I wouldn't be able to |
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troubleshoot issues with dmraid or raidtools. |
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|
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> I want to use software raid 1 and LVM together, is this doable ? anyone |
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> have pointers or a website for me to look on ? |
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Absolutely possible. Use mdadm to create your RAID 1 block device |
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(generally /dev/mdX) and then run pvcreate against that block device. At |
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this point all your standard LVM tools work like normal. |
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So that everything falls into place on boot, make sure your LVM |
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configuration scans md devices for pvs (the default configuration does) |
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and that mdadm attempts to recreate the device node on boot by adding a |
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line like: |
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ARRAY /dev/md0 level=raid1 num-devices=2 |
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UUID=b64934c5:85356513:9b13d76e:c0280a56 |
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to your /etc/mdadm.conf |
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|
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-- |
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"If there's one thing we've established over the years, |
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it's that the vast majority of our users don't have the slightest |
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clue what's best for them in terms of package stability." |
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-- Gentoo Developer Ciaran McCreesh |
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