We're using Zimbra 3.1 on CentOS4 Linux with 1GB RAM. The Zimbra client is quite slow to respond to requests, so I did a quick check of top and got the following unusual stats. High load average and unusual amount of swap being used.

Does anyone know what would cause only 470MB of RAM to be used out of a possible 1GB available RAM and then 512MB of swap? Very weird.

This server is currently supporting 15 users.

Any suggestions appreciated.

[admin@mail ~]$ top
top - 18:47:29 up 1 day, 3:58, 1 user, load average: 4.99, 3.14, 2.61
Tasks: 108 total, 3 running, 105 sleeping, 0 stopped, 0 zombie
Cpu0 : 2.5% us, 13.2% sy, 0.0% ni, 49.1% id, 35.2% wa, 0.1% hi, 0.0% si
Mem: 1043912k total, 469896k used, 574016k free, 992k buffers
Swap: 1052248k total, 513748k used, 538500k free, 37292k cached