MAXGROUPID(5)
NAME
maxgroupid - replicated volume number allocation mechanism
DESCRIPTION
The system control machine (SCM) has a file, /vice/vol/maxgroupid,
which contains the maximum replicated (aka group) volume number that has
ever been allocated in the system. This is used as a simple way to
guarantee that group volume numbers are unique.
Replicated (or group) volume ids are allocated out of the same namespace as
replica ids and non-replicated volumes ids. The latter two types of ids have
a 1 byte (8 bit) prefix to identify the server on which they are stored. We
suggest using prefixes in the range 00-7F for replicated volume ids, and
prefixes in the range 80-FF for other volumes. When initializing a system,
put the number you wish to use for the first replicated volume in
/vice/vol/maxgroupid. For example, if you wish to use 7f000000 as the first
replicated volume, create /vice/vol/maxgroupid with the number 2130706432.
FILES
/vice/vol/maxgroupidon the SCM
BUGS
This file should be salvaged, but it is not.
Removing this file (without reinitializing the whole system) is a recipe for disaster. Grave confusion will result if group (or any other) volumes are created with the same number.
SEE ALSO
servers(5), createvol_rep(8)
AUTHOR
- Jay Kistler, 1990, Created