http://now.netapp.com/NOW/cgi-bin/bol?Display=13880&Type=Detail

Though it's not clear from the description on that page, the problem occurs only when mixing different-sized disks in a single VOLUME. Having different-sized disks on the same filer, even on the same SCSI or fibrechannel adapters, is not a problem, as long as the different disks are kept in different volumes.

Also, there's no performance impact when right-sizing an oversized spare, i.e. using a spare 18GB disk as a replacement for a failed 9GB disk.

-----Original Message----- From: dnb@ccs.neu.edu [mailto:dnb@ccs.neu.edu] Sent: Monday, January 17, 2000 10:00 AM To: David Schairer Cc: mats.oberg@tietoenator.com; toasters@mathworks.com Subject: Re: problems mixing 18/9 GB disks?

Howdy- Could I ask for a little more clarififcation about this (either from you or the folks at NetApp)? The way I read this message was he was going to add 9G disks to a volume composed of 9GB disks and and 18GB disks to a volume composed of 18GB disks. Are you saying that:

a) having both 9GB and 18GB disks on the same *filer* is bad? b) mixing 9GB and 18GB drives in the same *volume* is bad (I would guess this would be true if one didn't watch out for the parity & spare drive gotchas)? c) having a volume served from two different *shelves* is bad (can't believe this is the case)?

Thanks!

Respectfully, David N. Blank-Edelman Director of Technology College of Computer Science Northeastern University