Clustering EXP300 and 4mx

[jmathergdv]

We have an application that needs one large single logical drive in a cluster. I'm wondering if anyone has ever attempted to set up clustering with multiple exp300's in a 2 node cluster, using a 4mx controller. My understanding is that this may not be possible without some sort of Third-Party Software solution like Veritas Volume Manager. Has anyone ever tried this and/or have further information?

 

[victorv]

hi,
I have often used EXP300 in 2nodes MScluster and 4?x.

EXP300 has 14 slots, 2 separated bus and 2 connectors, then 7 slots for each bus (scsi id of slot are 0,1,2,3,4,5,6 you can attach each bus on different systems also with different OS. In case of cluster or if you need all slots available to an host, using a switch, you can connect the 2 bus, obtaining a single bus .
(0,1,2,3,4,5,6 8,9,10,11,12,13,14 ) = 14 slots

If you are in a cluster env, you loose id=6, for the 2nd
adapter id, and max disk number becomes 13.

There is a knob in EXP300 called "unit id switch" but does not seems from doc that this can be used to translate ids
for the expansions following the first; in other storage system (DEC), this had this meaning.
If this was true, you could set to 1 the unit id and use 14 disks.

See doc:

http://www-3.ibm.com/pc/support/site.wss/MIGR-4NMKVZ.html

I don't know what is your config now (you have already an EXP300 and you want buy another), but now exist disks with very large capacity. If you say me your needing and actual situation, I can suggest, other sols.

Take in mind that exist disk of 146 Gb, and FasT solution
(fiber channel wired) are now enough cheap.

bye

 

[jmathergdv]

Thanks for your information. Currently we have one exp in the cluster that is full with 146gb drives. We just need to make sure we can add another exp to this existing exp and continue to have 1 large logical drive (except the quorum)...so any info on how you do that would be great...which actually leads to another question....Will there still only be the 1 quorum with 2 exp's in place?

Thanks.....