Gilles wrote:

>
>It's more desireable to assign each mirror set to different SCSI cards -
>but not always possible - and certainly not a reqirement.
>
>In any case, depending upon the environment, mirroring on a single SCSI
>card is preferable to not mirroring at all, though probably less desireable
>than using multiple SCSI cards.
>


Gilles is correct. It all depends on why you are mirroring. If you are
mirroring simply to protect the data against disk failure, then having
mirrored pairs on the same card can be OK (performance issues aside.) Of
course, you have to take into account that a hardware failure on a SCSI
adapter could corrupt both partners.

If you are mirroring to reduce downtime then you want to have the mirrored
pairs on separate adapters. For this option there should not be any single
point of failure, such as a SCSI adapter.

Doug.

Doug Werth                                     Beechglen Development Inc.
[log in to unmask]                                       Cincinnati, Ohio

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