ibm ds4700 / logical drive not on preferred path

a ibm ds4700 with four exp 810 units lost it`s preferred path setting for one controller /some logical drives. consequences : there were some machines with non-redundant paths connected to the san – these machines lost their mounted luns.(datastore for a mail machine, datastore for a fileserver with 14TB…) first i changed on the fibre channel switch fabric the zoneing to the healthy controller and remounted the drives to get the server systems back on production. after some research i seems to be clear that the solution is just only to map the logical drives back to the preferred controller/path … *sigh you can change the controller settings for the logical drives under production scenario. learned: do *all* fc/san connections redundant – don`t save money on your fibrechannel san design … 🙂

message on the storage manager / recovery guru : Logical Drive Not On Preferred Path

vmware / centos 5 network settings

copied vm centos 5 machines with fixed ip settings to a different esxi server. put the machines in a vm net with an active dhcp server. the centos machines switched at boot-time to dhcp and automatically disabled the fixed ip settings. centos creates a new interface configuration file with dhcp settings. the old config file is backed. why ? the mac adress has changed ! (vmware moving). to prevent this you should probably configure the mac adresses from the old esxi system or adjust the network cfg files on centos.

new virtualization project

i`m planning a new virtualization structure for a customer. this time based on three ibm x3650 m3 machines; one machine as iSCSI target, the other two machines with vmware ESXi 4.1, for sure it will be real fun to configure one x3650 m3 as a iSCSI target – hoping debian stable will install clean without patching the kernel for raid modules or something ….  🙂