- Q:
I have SCSI adapter brand XYZ (with or without several channels),
and disk brand(s) PQR and LMN, will these work with md to create
a linear/stripped/mirrored personality?
A:
Yes! Software RAID will work with any disk controller (IDE
or SCSI) and any disks. The disks do not have to be identical,
nor do the controllers. For example, a RAID mirror can be
created with one half the mirror being a SCSI disk, and the
other an IDE disk. The disks do not even have to be the same
size. There are no restrictions on the mixing & matching of
disks and controllers.
This is because Software RAID works with disk partitions, not
with the raw disks themselves. The only recommendation is that
for RAID levels 1 and 5, the disk partitions that are used as part
of the same set be the same size. If the partitions used to make
up the RAID 1 or 5 array are not the same size, then the excess
space in the larger partitions is wasted (not used).
- Q:
I have a twin channel BT-952, and the box states that it supports
hardware RAID 0, 1 and 0+1. I have made a RAID set with two
drives, the card apparently recognizes them when it's doing it's
BIOS startup routine. I've been reading in the driver source code,
but found no reference to the hardware RAID support. Anybody out
there working on that?
A:
The Mylex/BusLogic FlashPoint boards with RAIDPlus are
actually software RAID, not hardware RAID at all. RAIDPlus
is only supported on Windows 95 and Windows NT, not on
Netware or any of the Unix platforms. Aside from booting and
configuration, the RAID support is actually in the OS drivers.
While in theory Linux support for RAIDPlus is possible, the
implementation of RAID-0/1/4/5 in the Linux kernel is much
more flexible and should have superior performance, so
there's little reason to support RAIDPlus directly.