I "recently" (a few months ago) came across the inode64 entries in the
XFS FAQ. Unfortunately, I have a filesystem not mounted with inode64,
and I would like to know how many more inodes I can create in the
first 1TB before I run out, so that I can plan for a migration to
inode64 (if it's very few, I would make it a high priority; if not, it
can be done in a few weeks instead, for example). Is there an easy
way (or even a hard way) to query the filesystem for this information?
I also wanted to ask about the FAQ that says you can switch back from
inode64 to inode32. How does that work if an inode is created past the
1TB mark? How would the kernel know how to find an inode64 inode that
was created beyond the 1TB mark if the filesystem is subsequentely
mounted without inode64?