When using cvfsck to verify or repair an Xsan filesystem, the Xsan Volume's "File System Status" is reported as "Clean" or "Dirty", but not whether repair is needed or not.
The File System Status does not reflect whether the filesystem is damaged or not. Do not reference the File System Status when deciding whether or not a filesystem needs repair.
In order to determine if a filesystem is corrupted, look at the last lines of the cvfsck report. If you see a message such as this:
"*Warning*: !!READ_ONLY!! File system 'Volume_Name' would have been modified!"
... then your volume is in need of repair.