[Info-vax] RAID vs. MOUNT/BIND

[Phillip Helbig---undress to reply]

I might need some logical disks bigger than any physical disks I have.  
Controller-based RAID is not an option (don't have enough controllers 
for the needed redundancy), so the options are host-based RAID and 
volume sets.  If the only point is to create a larger logical disk, 
which is better?

HELP says:

     The following command creates a volume set with the logical
     name TEST3. The volume set TEST3 is not shadowed, however each
     element of the volume set (TEST3011 and TEST3012) is a shadowset,
     providing redundancy for the volume set as a whole.

     $ MOUNT/BIND=TEST3013 DSA3011/SHADOW=($1$DUA402:,$1$DUA403:),
     DSA3012/SHADOW=($1$DUA404:,$1$DUA405:) TEST3011,TEST3012 TEST3013

Presumably, the opposite is not possible (i.e. shadow a volume set with 
another volume set).  Right?

HELP says:

     If you mount an ISO 9660 volume using the /SYSTEM or /CLUSTER
     qualifier, and the volume label is not unique within the first
     12 characters, you must supply an alternate 12-character volume
     label using the qualifier /BIND=volume-set-name. If you choose
     this option, then Mount verification is disabled for the device.

Why is mount verification disabled in this case?  (Not relevant for my 
current problem; I just want to know.)

With host-based RAID, do I have the option of a) binding several small 
shadow sets into a larger RAID 0 device or b) shadowing two (or more) 
RAID 0 devices?  If so, which is better?