Re: raid1 issue, somewhat related to recent "debian on big machines"
On Tue, Mar 3, 2009 at 9:52 PM, Alex Samad <alex@samad.com.au> wrote:
> On Tue, Mar 03, 2009 at 12:26:27PM +0100, Goswin von Brederlow wrote:
>> Francesco Pietra <chiendarret@gmail.com> writes:
> [snip]
>
>>
>> That is a lot of raids. Have you ever thought about using LVM? The
>> different raid1 will mess up each others assumption about the head
>> positioning of the component devices. On read the linux kernel tries
>> to use the disk with the shorter seek and assumes the head is where it
>> left it on the last access. But if one of the other raids used that
>> disk the head will be way off.
>>
>> I would suggest the following scheme:
>
> this is what I would recommend as well
I understand that the double recommendation is fine. Though, I am
pressed by answering the referees about a submitted paper as they
requested additional computation. That was going on until the host
suspended access to sda. As I find risky to go on with one disk only
(for a many days computation), could you please explain how to
reactivate the removed sda, or format it to try if it recovers? I made
some proposals in previous post. Or indicated that the best is
replacing the disk with a new one.
Thanks
francesco
>>
>> sda1 / sdb1 : 100Mb raid1 for /boot (or 1GB for / + /boot)
>> sda2 / sdb2 : rest raid1 with lvm
>>
>> MfG
>> Goswin
>>
>>
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>>
>
> --
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