20 Aug
2021
20 Aug
'21
9:20 a.m.
On Fri, Aug 20, 2021 at 9:50 AM Peter Allan via cctalk <
cctalk at classiccmp.org> wrote:
How can I make a larger /usr partition? Is it possible
to do this at
installation time? There did not seem to be an option for this. Can it be
done by using an additional disk? That would seem likely, but not what a
system manager back in the 70's or 80's would expect to need to do,
especially as there is a relatively large amount of space left to create
/user1.
Ultrix-11 is old-school Unix. This means that it uses hard-wired partitions.
It's based on the controller that you use. So for an RD54 connected to an
RQDX3 would use the rq_sizes entry from dksizes.c:
/*
* Sizes for RD31/RD32/RD51/RD52/RD53/RD54/RX50/RX33 disks.
*/
struct rasize rq_sizes[8] = { /* RQDX1/RQDX2/RQDX3/RUX1 */
9700, 0, /* RD31-32,51-54 root (swap+error log -
rd51) */
17300, 9700, /* RD32/RD52/RD53/RD54 /usr */
3100, 27000, /* RD32/RD52/RD53/RD54 swap + error log */
-2, 30100, /* RD32/RD52/RD53/RD54 user files */
-2, 9700, /* RD51 /usr */
3100, 9700, /* RD31 swap + error log */
-2, 12800, /* RD31 /usr */
-1, 0, /* RD31-32, RD51-54 entire disk */
};
* Note - nblocks has two values with special meaning:
*
* An nblocks value of -1 specifies a partition length of
* the size of the entire disk minus the partition's
starting
* block number. In other words, the partition ends at the
* end of the disk.
*
* An nblocks value of -2 specifies a partition length of
* the size of the disk minus the size of the maintenance
* area minus the starting block number of the partition.
* In other words, the partition ends at the start of the
* maintenance area.
So a RD-54 is
* RD54
* +-----------------------+
* | 0 9700 root |
* | |
* +-----------------------+
* | 1 17300 /usr |
* | |
* | |
* +-----------------------+
* | 2 100 error log |
* | 3000 swap |
* +-----------------------+
* | 3 281068 user |
* | |
* | |
* | |
* +-----------------------+
* | 32 maintenance area |
* +-----------------------+
* 7 311200 (user = 311168)
*
and that's what you get. You could change the rq_sizes array, but that's
tricky to set up...
It's a lot easier to use a RA81 instead. It's 450MB instead of the 150MB
the RD54 in the
example and gives plenty of room.
You could also use a RA80 instead. It's a little smaller than the RD54 at
120MB, but it
as a 20,000 block /usr instead of the kinda tiny 17,200 block area of the
RD54. The RA60
is also an option at 200MB with the same 10MB /usr.
Warner
P.S. Kudos to the anonymous DEC employee that drew all the pictures for
each of
the supported disks in dksizes.