[Info-vax] USB disk enclosures

[David Froble]

Hans Vlems wrote:
> My DS10 at home runs axp/vms v8.4. It has a chinese USB interface that is
> recognized by VMS. Memory sticks of
various sizes work well and are recognized with their specific DNA device number.

Sure, throw that out there, and then forget to provide some specifics.  Perhaps 
others might want to try the device.


> Enter two 2.5" SATA disks, 80 GB and 120 GB respectively. I bought two
identical disk enclusures put the disks in and did an init/system on the 80G
drive on the DS10. Mounting worked well and I copied 40GB of disk images to it.
> Dismounted the DNA device. Disconnected the disk and replaced it with the
> 120G
disk enclosure.
> It got the same DNA device number. Init/system resulted in an error message
that the number of blocks was different from the previous time the device was
mounted. A backup to it failed and the DNA device was in mount verification state.

Ya know, I bet this could re-start the discussion on unloadable and reloadable 
drivers ...

:-)

Note, I don't do USB stuff, but, I'm guessing that your claim "recognized by 
VMS" and "works well" might not be quite as solid as you claim.  Could also be 
rather stupid drivers that don't know much if anything about removable media. 
They set up for the first media, and have no capability of re-setting up for 
other media.

Now, if you re-boot the system and try the 120G first, does it work?  This is 
the first thing to try.

> Apparently the same enclosure hardware for two different disks, both make and
> 
capacity confuses the USB drivers.
> 
> I connected both enclosures and sho device returned one DnA2: device while
> UCM
two disks were shown, both called DNA2.
> 
> Is there a workaround for this, so that I can use them both on the same
system, at least alternately?
> Hans