We are running RHEL 5.4 connected to EMC Clariion.
Have created storage on SAN for this server, device is /dev/emcpowerb which has two I/O paths, sda and sdb.

All is well except on reboot of the server I get a string of messages like:

Buffer I/O Error on device sda, logical block 0

It appears that something in the boot sequence is trying to access these drives before powerpath can present them to the host.

Everything works fine, but it is annoying to see these messages each time we boot.

Can anything be done to get rid of them.

Thanks

Nope. EMC has a primus article on this that states that they may be safely ignored... as long as they are only seen during boot. If you, however, encounter them after PP has started and the emc psuedo-devices have been initialized and managing paths, you might have a problem somewhere.