How cdm probe calculates inodes for zfs disk?
On Solaris platform cdm probe uses system call statvfs .
This call provides values of f_files and f_ffree
As far as calculation is concerned ,
iInodeMax = f_files
iInodeUsed = f_files - f_ffree
QOS_INODE_USAGE_PERC = (iInodeUsed * 100) / InodeMax
Below is response from Oracle regarding the values we’re using in CDM probe for calculating INODE data,
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In case of ZFS file system there is no preallocated files unlike other file systems , so there is no fixed value. These values change dynamically . So in case of ZFS , the value is maximum that could fit in f_files .
For ZFS file system though these values can change with increase in inode usage ,at a particular instance these value makes sense.
For clients who do not want to see INODE metrics , can disable it as it is configurable. Can manually uncheck the the inode QOS and threshold metrics ( this is by default unchecked ) in cdm probe
To summarize we cannot say that ZFS is not supporting inode information . The difference is , values are not fixed/predefined in ZFS’s case .
When needed (usage about to reach maximum limit) , maximum usage limit is increased dynamically . so they shows maximum value that can be fit in f_files .So it is up to individual client whether they are interested in these values or not.