Repeated logging in console On macOS Sierra I am seeing the following logged every 3 seconds. 

logd[67]: _handle_cache_delete_with_urgency(0x7f939281eb80, 3, 0)
logd[67]: _volume_contains_cached_data(is /private/var/db/diagnostics/ in /) - YES
logd[67]: 186377856 bytes of purgeable space from log files
logd[67]: _purge_uuidtext only runs at urgency 0 (3)
logd[67]: 0 bytes of purgeable space from uuidtext files


I rebooted into Recovery mode (Command-R during boot) and ran Disk Utility First Aid, with no change in behaviour.

With each run of First Aid I received the following in the Disk Utility list of messages:

resizing core storage logical volume structures ...
resized core storage logical volume ...
growing file system


Which seems odd that each run of First Aid would cause a change to the core storage system.

I'm concerned all of these messages in the log suggests I may have a disk error. Can I safely ignore these? Is my disk failing, or is this normal to have my log files flooded with messages every 3 seconds?
It turns out iStat Menus was the culprit. Upgrading to the latest version resolved the issue.