Archive for the ‘Linux’ Category.

Howto change MTU in Red Hat Linux

In Red Hat Enterprise Linux you can change the MTU (Maximum Transmission Unit) dynamically

# ip link set mtu eth0 512

or using ifconfg

# ifconfig eth0 mtu 512

but to make it permanent even after a reboot you need to add the MTU setting to the correct interface configuration file.

continuing the above examples, that would be:





Qlogic HBA WWN’s in SLES 9/10

If using Qlogic HBAs in SLES 9, the recommended driver is the vendors own driver. In this case wwn's as well as wwpn's could be found by looking in /proc/scsi/qla2xxx
# cat /proc/scsi/qla2xxx/* | grep node


# cat /proc/scsi/qla2xxx/* | grep adapter-port

In SLES 10 the native HBA driver is the recommended. You can find WWNs and WWPNs by looking in /sys/class/fc_host or using the systool

# cat /sys/class/fc_host/host?/node_name


# systool -c fc_host -A "node_name"