1 year ago
Not, presumably a 1900 capable of running George 3, since that had one of the best backup systems I've ever seen. George automatically extended its file system onto tape, by making backups at predefined intervals onto 1 to 3 tapes in parallel. If the on-disk part of the filing system got over full, the largest, oldest backed up files were erased from the disk store until the free space quota was reached. When a logged-on user or batch job needed any of these files, George 3 asked the operator to load a tape containing the most recent copy(s) of the file(s) and put them back on disk. It also had the ability to free old backup tapes by moving any files that hadn't been deleted and had no more recent backups back to disk and then removing that tape (and its parallel copies) from the active backup tapes list.
VME/B, the 2900 OS did something recognisably similar, though with tweaks to deal with large databases - IIRC these could be duplicated onto removable disks rather than tape. True enough, but a well-designed security system should not interfere with normal activity by an authorised user. UNIX/Linux is less annoying than other OSen I've used, but it limited by being a two-level system ('root' + other users).
I think George 3 was better here, since it had a user hierarchy. Under it :manager was the equivalent of 'root' and also owned the whole filing system. It could create other users and give them storage and CPU budgets. These in turn could create subordinate users and give parts of their budgets to them.
FWIW, Multics (1967) was the first OS with a hierarchic filing system.
George 3 (1969) seems to be the first widely used OS to support a hierarchical filing system (I think there must have been more 1900s running George 3 than the 80 Multics installations: I've used or been sysadmin on 6, but I have no idea how many G3 installations there were overall.
UNIX doesn't seem to have left Bell Labs until it was rewritten in C (1973), but wasn't really portable before 1978.
Microware OS9 was released 1980, so precedes MS-DOS (1981) by a year. Linux was first released in 1991.
-- Martin | martin at Gregorie | gregorie dot org