2010/7/14 Jens Neu <jens.neu at biotronik.com>: > Dear all, > > unfortunately I observe drastic drops in read- performance when I connect > LUNs >2.2T to our Centos 5.5 Servers. I suspect issues with the GUID > Partition Table, since it happens reproducibly only on the LUNs >2.2T and > goes back to normal performance when using a LUN <2T with "normal", Legacy > MBR partitions. > All machines are CentOS 5.5 (and RHEL 5.5) on IBM Blades LS21/LS41, all LUNs > via Brocade 4G FC Switches from a SUN 7310 Unified Storage, EXT3 filesystems > with standard settings. > > Any hints? I think ext3 is a bit slow on so big LUNS, try xfs or similar? -- Eero