Nagios reports a warning regarding inodes.
DISK WARNING - free space: / 334567 GB (21% inode=96%)
The warning could easily be misread. Nagios says there are still 96% of inodes available, but the free space on the partion is at 21%.
So you are not running out of inodes but the value for the free space has gone below the threshold of 25% configured by default in UCS Nagios.
Set the value to the preferred value (ie 20%) on in the computer object in UMC.