I have installed rhel 5.4 with rdac driver and assigned the 8 LUNs from IBM DS 3400 storage. Server and storage is connedted with two Cisco MDS 9124 switch. Zoning is configured in both the switch. Server is having one HBA card with dual port and one port each connected to san switch. Storage controller is having two host port and each controller is connected to each san switch.
When i switched off the one san switch and fire the fdisk -l command in redhat it tackes time to come up with the output. This is a installation phase i want to know the working process in redhat. I have not checked with copying data to san disk from external source during powering off one switch.
Same type of configuration i have done in AIX i did not find any problem like this as mentioned above.
Will the data connectivity will loose for some second if one switch will fail?
If you have any suggestion are most welcome.
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2 replies Latest Post - 2010-07-15T23:09:27Z by malahal
Pinned topic SAN disk on RHEL 5.4
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Updated on 2010-07-15T23:09:27Z at 2010-07-15T23:09:27Z by malahal
malahal 1100009N014 PostsACCEPTED ANSWER
Re: SAN disk on RHEL 5.42010-07-15T23:05:21Z in response to SystemAdminUsually the DS3K works in active/passive mode where only one path is active. If
you switch off one Fabric switch, the corresponding HBA should detect link
down. After some timeout, the system should reject all I/O's on that path.
If you use multipath, the multipath software will failover to working path
after certain time period. All I/Os will be retried by the multipath driver
after switching over to the working path. Applications will not notice any
failure unless it is a tape drive related applications as some of the tape
drive commands can't be retried.