to RAID-5. peter claims that it might be faster for sequential
reading, since the drive caches don't trip over the parity blocks. I
have seen no evidence to support this, but it's a trivial change.
Requested-by: peter
Change checks for striped or RAID-5 plexes to a macro 'isstriped',
which now also includes RAID-4.
Change checks for RAID-5 plexes to a macro 'isparity', which now also
includes RAID-4.
atoi(): Remove, nobody was talking to it.
give_sd_to_drive: If no space is available, make the subdisk down,
don't delete it.
Change the manner in which the subdisk count was maintained to avoid
cases where the count was not adjusted correctly.
config_drive: Check if we have subdisks referencing us, and add them
if so. This fixes problems which arose when a drive is replaced in a
running system.
config_sd: Add support for a keyword 'partition', whose meaning will
be revealed in the fullness of time.
Cosmetic: Shorten some console messages.
Approved-by: jkh