Thursday, February 08, 2007

This post is a bit late, but I figured people would be interested.

I started to re-organise Edinburgh's dCache at the end of last week. I've been meaning to do this since purchasing a qLogic HBA just before the holidays but have only now managed to find time to do the work. The new card is a QLA3242 (2Gb, dual port) and our intention is to use it to connect a dCache pool node
( directly to the University SAN via fibre channel, rather than using NFS (which we saw led to lots of problems with stale file handles and terrible write rates).

The installation went fine, kudzu did it's job well and immediately picked up the new card after a reboot. We are using the qla2300 module, loading it at boot time. There were teething problems in seeing the new scsi devices from the SAN, but these have since disappeared. Still need to do a couple of things before getting the storage into dCache. I need to properly setup multipathing (any advice would be appreciated) and also to format the 1.6TB volumes. Each volume is it's own independent set of disks which eases the configuration issues slightly since I don't have to worry about simultaneous reading/writing to the same disk.

All of our IBM disk is now hanging off of pool1 again and this is our currently our only gridftp door. Strangely I've not seen any CLOSE_WAITs recently....

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