Running into continuous "swap space below 10 percent free"
warning messages when Netscape Enterprise 3.5 is initialised.
-------- Before any webservers are started : ----------
Swap partition /dev/rz0b (default swap):
Allocated space: 16384 pages (128MB)
In-use space: 40 pages ( 0%)
Free space: 16344 pages ( 99%)
Total swap allocation:
Allocated space: 16384 pages (128MB)
Reserved space: 5143 pages ( 31%)
In-use space: 40 pages ( 0%)
Available space: 11241 pages ( 68%)
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
3 35 16 5124 5167 1080 25K 6998 6130 89 5275 0 21 246 68 3 4
93
2 36 16 5252 5030 1089 338 168 53 0 23 0 7 256 62 3 3
95
2 36 16 5252 5030 1089 29 0 28 0 0 0 0 190 46 0 1
99
2 36 16 5252 5030 1089 28 0 28 0 0 0 1 191 49 0 1
99
-------- With one instance of the webserver running : -----
# swapon -s
Swap partition /dev/rz0b (default swap):
Allocated space: 16384 pages (128MB)
In-use space: 389 pages ( 2%)
Free space: 15995 pages ( 97%)
Total swap allocation:
Allocated space: 16384 pages (128MB)
Reserved space: 10703 pages ( 65%)
In-use space: 389 pages ( 2%)
Available space: 5681 pages ( 34%)
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
4 49 16 7526 2621 1225 30K 7829 8070 154 6914 0 26 303 91 3 4
93
2 51 16 7542 2599 1231 332 76 58 0 22 0 0 305 170 2 2
95
4 49 16 7542 2599 1231 35 0 34 0 0 0 1 272 174 0 1
99
3 50 16 7555 2586 1231 76 7 40 0 0 0 27 264 185 2 1
97
--------- With the second instance started : -----------
# swapon -s
Swap partition /dev/rz0b (default swap):
Allocated space: 16384 pages (128MB)
In-use space: 389 pages ( 2%)
Free space: 15995 pages ( 97%)
Total swap allocation:
Allocated space: 16384 pages (128MB)
Reserved space: 15362 pages ( 93%)
In-use space: 389 pages ( 2%)
Available space: 1022 pages ( 6%)
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
5 56 16 9249 816 1308 36K 8399 10K 350 8963 14 31 354 115 4 4
91
3 58 16 9265 794 1314 348 78 62 28 22 0 0 406 216 3 3
94
2 59 16 9264 795 1314 38 0 36 0 0 0 0 293 218 0 2
98
2 59 16 9264 795 1314 139 29 36 0 2 0 9 295 231 1 1
98
Refering to the Digital webserver tuning paper (found
at
http://www.digital.com/internet/document/ias/tuning.html),
I used the dxkerneltuner to change the vm's vm_mapentries
from 200 to 20000 and rebooted.
This didn't help much. (in fact the above vmstat is taken with
vm_mapentries at 20000)
Past summaries in the archive suggested that increasing the
vm_mapentries did the trick; others suggested deleting or
renaming the symlink /etc/swapdefault but that doesn't even
exist on my box.
So, I figured I could configure the process (in this case, Netscape
Ent. server 3.5) to reserve or use less memory.
But the only 'performance tuning' available is to reduce the
Max No of Simultaneous Requests from 512 which I don't really
want to do. (and I've messed up my magnus.conf
and other config files enough to know not to edit them by hand anymore).
Unfortunately I have no free partitions to allocate
another swap space, and in any case this doesn't seem like
a scalable solution judging by the amount of swapspace each
instance of netscape reserves. I should be able to hang 10
webservers off this machine (at least) but not at the current
rate (about 36 MB swap space per instance).
Any advice much appreciated,
thank you very much,
chas
Received on Tue May 05 1998 - 07:49:33 NZST