Adding disks to expand raid

[Nicolas Triantafillou]

Hi all,

I have a poweredge 2850 running Debian (sarge), with 3x 300GB 10k scsi 
disks in raid5 (perc4/dc), and I'm running out of space.

Is it possible to add disks to the raid and expand one of the partition 
sizes? (the last partition on the disk is the one I want to expand) or 
should I create a new array with 3 more disks and just have different 
partitions?

I've searched the dell forums but most there seem to be windows admins.

Cheers,

Nick.