root is on a multipathed device multipathd can not be stopped
 

Hi guys.

I am installing RH 5.8 booting from a HP SAS storage with multipath.. the server is a HP proliant..

there is a / partition, swap and /var all in the storage..

the issue is when I restart the server while the system stop all service one says ERROR... and the error is this:

root is on a multipathed device multipathd can not be stopped

I can restart the server and it will boot.. but I am not sure if this is a critical issue that could affect me in the future.. the server will be in production and the only reason for restart or shutdown will be a for a very critical failure...

I am trying to find information about this but I allways end in any page showing the script which stop this service.. not sure if it is a bug or should I replace the original script with the one I found..

the other thing is if I update the system with yum update it wont boot with the new kernel.. I think I should rebuild the kernel image with mkinitrd.

If I run the command multipath -v0 or 1 2 it doesnt show anything..

any idea?

thanks in advance

If you are booting off the san, multipathd cannot be stopped because your data to shutdown the server is on the SAN. If multipathd gets turned off it will not be able to communicate with the san thus your data is not accessible. The main implication with booting from the san is you may have slow downs if there is anything wrong with the connection from the server to the san. For instance we had a fibre channel go down and that server went turbo slow...like 5 minutes to log in, dropping connections etc...

As for the kernel - try reloading the kernel with yum and check grub for ordering. When you install it with yum it should edit the grub.conf file, but there may be something preventing it. For example permissions.

Hopefully that helps.

An alternative to SAN boot is PXE, or similar protocol, with a local / partition (Or, NFS mounted partition); with everything else SAN mounted. It's not a bad deal, since generally, the / partition wont change enough to merit central management, as long as you SAN mount /var, /opt/...