I'm working on a project that involves supporting
multipath(*) access under the 2.2.x kernel. I known that
neither the current LVM and MD subsystems support this,
and as a first attempt at it I'm writing a MD personality
for multipath.
Anyhow, here's my question: has anybody written any
documentation on what a RAID personality needs to do,
and if the personality superblock is (a) required to
be on-disk and (b) if the automatic superblock probe is
done even on disks that don't have an 0xFE partition.
Is suspect (a) is true, and (b) is false, but I'd
like some confirmation. Also, it's a PITA to add a
new personality (requires kernel patching) and I was
wondering if the 2.4.x raid subsystem is planned to
use a name-based personality registration (like the
char, block, ether, vfs, etc subsystems)
Thanks in advance. I'll be reading the list, so
no need to CC me.
* Multipath - having two controllers on one machine that
can each see the same device, ie controller 1 -> /dev/sda,
controller 2 -> /dev/sdb, yet /dev/sda and /dev/sdb are the
same physical device. Useful in high-availability situations.
--
Jason McMullan, Senior Linux Consultant, Linuxcare, Inc.
412.422.8077 tel, 412.656.3519 cell, 415.701.0792 fax
[EMAIL PROTECTED], http://www.linuxcare.com/
Linuxcare. Support for the revolution.
