> > Our RS6K has been running smoothly with 320Mb memory (the primary
> > paging space as recommended when AIX 4.2.1 was installed is 352Mb)
> > We are going to run more memory intensive apps on the machine, so we'll
> > install 256Mb more RAM. Now could someone suggest the optimum size
> > of the extra paging space (assuming we add one more paging only)
> > to add for this amount of extra memory (Since we'll not install the
> > OS again, so i wouldn't be able to have the OS calculate a good value
> > for me like the last time we have 4.2.1 freshly installed)
> Approximate calculation for paging space requirement is RAM + 16 MB,
> but you might need more paging space depending on the type of applications
> you're using. Databases usually need more.
> The important thing is to use multiple paging spaces of similar size on
> different disks. If you are going to run more memory intensive applications
> I would add another paging space of 300 (or 352) MB and see what
> happens. If you are going to have many smaller paging spaces on many disks,
> you have to reduce the size of hd6 (the primary paging space), which
> requires special treatment.
Whoa! He shouldn't necessarily add separate paging spaces on different disks.
It really depends on what his machine does. This could*his performance
all up with added disk I/O. If it's a database machine, he'll be done for. If
not, it should work okay, but adding more paging spaces 'willy-nilly' is just a
bad idea. It should be planned accordingly. He may only need to increase the
existing paging space. Also, the "rule-o-thumb" for paging spaces is:
total paging space = 512MB + (memory size - 256MB) * 1.25
Separate paging spaces should be of equal size, if possible, for the
round-robin algorithm. The primary paging space can be a bit larger, though,
with no ill effects. In fact, it should be a scosh larger for booting
Robert Kennedy - These foolish ideas are all my own.
Boeing Space and Defense Group
Kent Space Center
System Administration - CAD/CAM
Small minds discuss people;
Average minds discuss events;
Great minds discuss ideas.