We bought a config on specs. of a reseller. It consists of:
1 ESL9000 library with 10 tape drives
1 8 port fibre channel switch
2 modular data routers with a total of 5 interfaces to the library
(2 drives each)
2 kgpsa fibre channel controllers for an Alphaserver 4100 running
tru64 v4.0f
When we first started using this config we had 1 kgpsa, and were
able to see and use all 10 tape drives. We then added the second
kgpsa (which was specified by the vendor to provide sufficient
bandwidth to drive 10 drives backing up multiple hosts connected
to this one via 100Mbit copper) and on reboot we see 20 tape drives -
*rmt0* -> *rmt9*
and *rmt10* -> *rmt19*
It appears, based on output from mt queries, that rmt0-9 are from
the first controller, and rmt10-19 are from the second controller,
and these are duplicate views of the same drives.
I have Compaq phone support researching this, but am wondering if anyone
else has a similar config or any insights into this. It appears as if
perhaps the vendor was wrong, that you can't actually use 2 controllers in
this config without some kind of kludge where we perhaps use:
*rmt0* -> *rmt4*
and *rmt15* -> *rmt19*
and delete the rest of the device files.
Here's a stab at an ugly ascii picture: 2 2 2 <---- # of drives
| | | bus talks to
____________________ _|_|_|__
host -kgpsa0----------|8 port fiber switch|---|mdr1 |
-kpgsa1----------| | --------
| | _____
| |---|mdr0|
-------------------- ------
| |
| |
2 2 <---- # of drives bus talks
to
As you can see, each HBA sees all drives via the switch. Does this
make sense? What do you think about having sufficient bandwidth to
backup upwards of 25 hosts thru 1 HBA to the switch/library containing
10 drives? What about if we moved the server to Gigabit ethernet,
as we are considering? We are using Networker, a minor version or two
back, as our backup software. Comments welcome.
Regards,
Judith Reed
jreed_at_appliedtheory.com
Received on Tue Feb 13 2001 - 21:57:22 NZDT