How do I plan RAM and Swap space on a workstation?
(Rule of Thump?)
--------
Most of the informations from swapon -s or vmstat or top
are concerning the very moment I issue the commands.
How do I get informations about the top / average usages?
Also, how do I interpret the information correctly?
How do I calculate the needed additional RAM so that paging is reduced to
an acceptable amount?
How do I calculate the really needed swapspace?
How are you planning this? Which information are you using?
How are you collecting this information?
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some details, examples, background information:
============
After the upgrade to DU4.0b (with CDE surface) one of our workstations
(64MB RAM) seems to be much slower (swapping).
Also, swap space was too small, which I increased now.
This machine is used for interactive logins (X11) and some computing jobs
with nice 19.
At the moment I get
# vmstat 2 4
Virtual Memory Statistics: (pagesize = 8192)
procs memory pages intr cpu
r w u act free wire fault cow zero react pin pout in sy cs us sy id
4124 18 4427 167 2663 24M 1M 1M 2M 2M 88K 30 153 326 94 2 5
4124 18 4442 152 2663 154 12 120 31 8 0 4 30 347 96 4 0
4124 18 4442 152 2663 95 0 95 0 0 0 7 31 343 96 4 0
4124 18 4441 152 2664 95 0 95 0 0 0 6 24 344 96 4 0
swapon -s gives:
...
Total swap allocation:
Allocated space: 68786 pages (537MB)
Reserved space: 23145 pages ( 33%)
In-use space: 10005 pages ( 14%)
Available space: 45641 pages ( 66%)
On an other workstation (384MB RAM) which is mainly used for computing
(no monitor attached to it) I've got the feeling that there is not
all of the RAM really used.
vmstat 2 4 currently gives me
# vmstat 2 4
Virtual Memory Statistics: (pagesize = 8192)
procs memory pages intr cpu
r w u act free wire fault cow zero react pin pout in sy cs us sy id
5122 20 33K 7440 6658 20M 2M 8M 246K 3M 1306 24 310 324 90 1 9
5122 20 33K 7425 6658 159 3 133 0 6 0 8 3K 357 97 3 0
5122 20 33K 7425 6658 111 0 111 0 0 0 8 4K 266 97 3 0
5122 20 33K 7425 6658 111 0 111 0 0 0 4 3K 344 97 3 0
swapon -s gives:
...
Total swap allocation:
Allocated space: 212769 pages (1662MB)
Reserved space: 41433 pages ( 19%)
In-use space: 11211 pages ( 5%)
Available space: 171336 pages ( 80%)
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TIA,
Rainer Landes, eMail: Computer-Administration_at_Physik.uni-karlsruhe.de
Tel(+49)721 608 3578
http://www-comp.physik.uni-karlsruhe.de/
Computer facilities of the Faculty of Physics, Univ. of Karlsruhe, GER
Received on Thu Mar 06 1997 - 16:28:46 NZDT