"Daniel D. Arrasjid" <[EMAIL PROTECTED]> writes:
>
>We're about to deploy DCE/DFS services for High Availability on SUN
>systems. The model is very similar to IBM's DFS HA solution.
>Basically, you have two machines that are attached to the same
>storage system. All DCE/DFS related files are located on this
>shared storage system. I imagine, a similar solution could be
>implemented with AFS.
>The primary machine is configured as the DFS server, the secondary
>machine simply watches for the primary to fail(using a commerical
>solution). When failure is detected, the secondary machine changes
>it's ip address, imports the storage system, and starts up DCE and DFS
>services.
>The DCE/DFS startup/recovery process takes about 10 minutes to complete.
I'm not clear why you would actually want this solution -- with
good hardware, your time (AFS) for fsck+salvager+attach is on the order of 30
minutes. You are 'protecting' against the loss of a system, but I have
found that to be quite rare. Most of our AFS outages have been
software-related, not hardware. (Of course, in general, we mirror
root disks and RAID 5 data disks, so our exposure to disk failure isn't
bad). Are you seeing a different failure pattern?
There are circumstances where you cannot tolerate the difference in
downtimes, but the cost of such a solution is rather high, and needs
to be weighed against the real benefits.
Steven Jenkins
--
Steven Jenkins
