Changing disks in RAID-5

["MITTELHEISSER Jean Claude" <mitteljc@xxxxxxx>]

Hi all,

We have a 620 in V4R2 with 6 disks (4.19 Gb #6807), 1 RAID-5 controller (#2741) 
and 1 tape unit (1/4 inch 2.5 Gb #6481). It will die at end 2005. So we don't 
want to make too much investments, but we have to add some disk storage. We 
will ask IBM if we can add new cards. But we thought about replacing some cards 
by others with higher volume (perhaps 8.58 Gb). At that level, is it possible 
to disable a 4.19 Gb disk, unmount it, mount a new 8.58 Gb one, activate it 
under READ-5 and repeat the operation for a second one ? Or is it easier to 
backup the whole machine, stop it, replace some disks and restart from tapes ?

Thanks.