GFS and iSCSI

[Matthew B. Brookover]

> b) Is implementing DLM better than GULM? It sounds better without needing a
> dedicated lock manager?


DLM does not require dedicated lock servers.  We are getting ready to
upgrade from 6.0 to 6.1 and switch to DLM.  The GULM servers will become
additional web servers.


> c) Can I implement GFS without needing a HBA i.e. since I'm using iSCSI,
> would I suffer too badly in CPU usage if I were to use a dual Intel
> Pro/1000GT GigE adapter (maybe use Ethernet bonding or DM multipathing?) for
> better performance?


I have never compared the performance between an ISCSI SAN and a fiber
SAN.  The cluster here is all ISCSI and seems to be fine with the dual
Intel Pro/1000 cards.  We bonded them together on 2 different Cisco 3750
switches.  According to the statistics from then network people, the 6
servers and ISCSI SAN hosts regularly hit 120MB/sec.

Your biggest problem will be fencing.  We hacked up a perl script to
fence with SNMP in the Cisco Switches.

You might want to get on the cluster mailing
list:https://www.redhat.com/mailman/listinfo/linux-cluster

Matt