2000-12-16 13:33:41

by Charles Wilkins

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Subject: kernel software raid support

What is the status of software raid development in 2.2.x?

There seems to be a growing number of hacks addressing kernel raid support, tools, and such specifics as read balancing, yet the kernel contains very old code for raid support which seems to act as nothing more than a placeholder for patching.

Would anybody happen to have a current list of working patches for a decent implementation of software raid1 using the 2.2.18 kernel that employs some level of read performance that exceeds that of 1 harddisk?

Regards,
Charles


2000-12-16 13:44:41

by Arjan van de Ven

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Subject: Re: kernel software raid support

In article <[email protected]> you wrote:

> Would anybody happen to have a current list of working patches for a
> decent implementation of software raid1 using the 2.2.18 kernel that
> employs some level of read performance that exceeds that of 1 harddisk?

This may seem odd, but it is actually not possible to get a sequential read
performance > 1 harddisk with RAID1 for single-threaded ussage patterns, given
the current on-disk structures.

I have a hack in my (2.4) tree that works around this limitation, but the
on-disk format is incompatible with the stock kernel, so it is no candidate
for inclusion...


Greetings,
Arjan van de Ven