2001-11-14 13:40:53

by Roy Sigurd Karlsbakk

Subject: RAID-5 build time calculation?

hi all

I apologize if this is more of a support question, but I couldn't find it
anywhere...

How long time may I have to wait for kernel to build a software RAID-5 on
12 18GB 15k SCSI drives? Algorithm is set to left-symmetric and persistent
superblock is 1.

What can be done to speed this up_

thanks

roy
--
Roy Sigurd Karlsbakk, MCSE, MCNE, CLS, LCA

Computers are like air conditioners.
They stop working when you open Windows.

2001-11-14 15:27:20

by Steve Lord

Subject: Re: RAID-5 build time calculation?

On Wed, 2001-11-14 at 07:40, Roy Sigurd Karlsbakk wrote:
> hi all
>
> I apologize if this is more of a support question, but I couldn't find it
> anywhere...
>
> How long time may I have to wait for kernel to build a software RAID-5 on
> 12 18GB 15k SCSI drives? Algorithm is set to left-symmetric and persistent
> superblock is 1.
>
> What can be done to speed this up_
>
> thanks
>

I have seen the raid resync get stuck at really slow rates, it seems to
start running faster if you echo a larger number into

/proc/sys/dev/raid/speed_limit_min

You can look at /proc/mdstat to see how the rebuild is progressing.

Steve