* Fast RAID rebuild?
@ 2003-07-22 11:49 danci
2003-07-24 21:38 ` Warren Young
0 siblings, 1 reply; 3+ messages in thread
From: danci @ 2003-07-22 11:49 UTC (permalink / raw)
To: linux-raid
Hello!
I have a 3 disk RAID-5 array with one spare disk on two IDE controller. As
I'm experimenting with kernel and drivers, sometimes my kernel doesn't
detect one of the controllers and therefore marks one of the RAID disks as
faulty. The RAID-5 is my root fs...
Next time I boot the kernel with all disks detected, RAID starts
rebuilding which takes a long time - pretty unconvenient for testing...
Is there a way to quickly add the disk back to array without resyncing
- something like 'mdadm --unfail'? :)
D.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Fast RAID rebuild?
2003-07-22 11:49 Fast RAID rebuild? danci
@ 2003-07-24 21:38 ` Warren Young
2003-07-25 6:09 ` danci
0 siblings, 1 reply; 3+ messages in thread
From: Warren Young @ 2003-07-24 21:38 UTC (permalink / raw)
To: linux-raid
danci@agenda.si wrote:
>
> Is there a way to quickly add the disk back to array without resyncing
> - something like 'mdadm --unfail'? :)
md is right not to trust the state of the replaced disk. Just in order
to get to the mdadm point, you have to boot up, which means files have
changed on the live disks relative to the one that was temporarily
missing. You'd risk massive corruption by forcing it to accept the new
disk without rebuilding the array.
You maybe could get away with this in a hardware RAID system because you
can administer the array before the OS comes up. None of the RAID cards
I've ever played with allow this, though.
The real solution to your problem is to put all the disks on the same
kind of controller. A 4-port 3Ware card, for instance. Then all disks
come up together or none of them do. You can still use Linux soft RAID
with most hardware RAID cards, if you must. Or, if you want to cheap
out, get a 2-port Promise IDE card and put the three disks on it.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Fast RAID rebuild?
2003-07-24 21:38 ` Warren Young
@ 2003-07-25 6:09 ` danci
0 siblings, 0 replies; 3+ messages in thread
From: danci @ 2003-07-25 6:09 UTC (permalink / raw)
To: Warren Young; +Cc: linux-raid
On Thu, 24 Jul 2003, Warren Young wrote:
> danci@agenda.si wrote:
> >
> > Is there a way to quickly add the disk back to array without resyncing
> > - something like 'mdadm --unfail'? :)
>
> md is right not to trust the state of the replaced disk. Just in order
> to get to the mdadm point, you have to boot up, which means files have
> changed on the live disks relative to the one that was temporarily
> missing. You'd risk massive corruption by forcing it to accept the new
> disk without rebuilding the array.
I thought it shouldn't work and I said so to the guy asking me... But I
just asked to see if *maybe* it is possible somehow.
Thanks for the answer,
D.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2003-07-22 11:49 Fast RAID rebuild? danci
2003-07-24 21:38 ` Warren Young
2003-07-25 6:09 ` danci
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