Adding Fibre Promise RAID to Fibre channel

Hi everybody! This may be an easy question to answer... I have a Xserve (10.4.11) an Xsan pooling two Xserve RAIDS... 15 TB of usable storage... 3 provideo clients on Fibre, each sharing the XSAN... I would like to hang a promise RAID off of this server... not for online storage, but for backup only... My question, without creating a new data pool in my Xsan, can I hang a Fibre Promise RAID off of the Xserve; without it broadcasting itself as a volume at all of the Fibre clients? I simply want it to be a volume available only to the Xserve; to catch data for a d2d2t solution. Thanks,