Turning Off Hsperfdata To Reduce Java Disk Access

Summary

If you notice a small amount of disk activity during idle periods, hsperfdata (Java performance data monitoring) may be the cause. To turn off:

Add -XX:-UsePerfData to JAVA_OPTS
For the H2 database: Add this in h2.sh
For Netbeans: Add this in netbeans_default_options in {NETBEANS_HOME}/etc/netbeans.conf

Confirmation

To confirm the behavior, look in /tmp/hsperfdata_YOUR-USERNAME (on Linux). The folder should be empty. If any folders are present, their names are the process IDs of the processes still writing performance data.

Detection

For detecting this and other similar disk access issues, iotop is useful. To launch:

sudo iotop

Then type a to enter 'accumulate' mode, which will show you cumulative IO over time, letting you see the largest consumers over time. use the left arrow to move to DISK_WRITE or DISK_READ as you prefer to see the largest consumer by category.

Last modified on 18 May 2025 by AO