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Am 2010-12-10 16:41, schrieb Volker Armin Hemmann: |
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> On Friday 10 December 2010, Stefan G. Weichinger wrote: |
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>> Am 09.12.2010 18:21, schrieb Volker Armin Hemmann: |
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>>> Put /boot on raid1, / on raid6. Don't bother with lvm - it is |
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>>> just another layer that can go wrong. |
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>> |
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>> You mean "don't use lvm for /" ? ... for other stuff it's very |
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>> useful, isn't it? |
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> |
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> no, I mean don't use lvm. It is a very compley, easily broken layer |
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> reducing data safety. |
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ok .... hmmm |
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> There is no need for lvm with bind mounting and ln -s. |
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I don't fully get that yet ... |
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>>> If Raid6 is like raid5 you should be able to have the kernel auto |
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>>> assemble everything, so no initrd is needed. Pay attention to the |
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>>> metadata format when creating the raid. Also have a look at |
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>>> stripe sizes. And stripe_cache_size. |
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>> |
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>> Thanks for your reminders. What exactly do you think of with |
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>> stripes and sizes? You point at the performance-impact? large files |
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>> vs. small files etc? |
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> |
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> stripe size has nothing to do with big and small files. But choosing |
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> the wrong stripe size can impact your performance very, very badly. |
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> We are talking about abysmal performance, Challenger depht abysmal. |
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> XFS and ext4 - for both is a lot of documentation available about |
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> choosing the right stripe size. |
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> |
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> stripe_cache_size can be set in /sys and has a 4-5x performance |
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> impact on raid5 (where I tried it). A good size for me is 8192. For |
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> example. |
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Ah, yes, already found that and I will check that out soon. Thanks! |
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