When synchronizing to a file system that does not support extended attributes, a sync job will fail with an error similar to this one:

"target does not support ctime checking: '/Volumes/...'"


The reason for this error is the following:

The ctime cannot be set or modified, so in order to be able to compare the ctime of a source file/folder with its copy on the target filesystem, P5 saves the ctime as an extended attribute on the target filesystem. In case the target filesystem does not support extended attributes and this check fails, the sync  job will abort with the above error message.

In such cases, the ctime comparison must either be turned off, or a different filesystem (one that supports saving extended attributes) must be chosen as the target.

In the current P5 release (5.6.4 as of this writing) the ctime check can be turned off by unchecking the "Access and attribute changes" box in the expert settings of the sync plan settings.


Please note: HFS+, APFS, NTFS support storing extended attributes "out of the box". Other filesystems, e.g. ext3, ext4 Linux filesystems must be mounted with the user_xattr mount option in order to support it.