FDT routine access can now be traced. This will show access to the driver which is otherwise hidden, since some driver functions can complete in the FDT routines. It can be enabled with $ LD TRACE/FDT (Alpha only). Accurate timing of I/O requests can now be done by enabling it this way: $ LD TRACE/ACCURATE (Alpha only). This allows I/O duration to be measured with a resolution of one microsecond, as opposed to the normal 10 mSec accuracy. The drawback is that if this is used all I/O has to go through the primary processor. Container files may now reside on remotely mounted NFS volumes. Note however that members of a shadowset may not be used if they reside on such a device. This is because the NFSdriver does not support the IO$_WRITECHECK function. This restriction will be lifted in a future release. The restriction of the maximum size of the logical disk not exceeding 2097120 blocks without specifying the geometry has been lifted. Any size up to the size of the disk holding the containerfile is allowed.