The most annoying error - cannot mount '/home': directory is not empty

Was working on migrating few SVM metadevice based filesystems to ZFS filesystem on Solaris 10 U8 and for the reason I have created ZFS filesystems with temporary mountpoint under /mnt like:

# zfs create –o mountpoint=/mnt/home –o quota=2g rpool/home

After creating this filesystem I’ll sync the data from metadevice based file system to ZFS based filesystem residing under /mnt like:

# rsync -axP --delete /home/ /mnt/home/

Once the data migrated I’ll un-mount the metadevice for /home and rearrange the mount point for ZFS filesystem back to /home using:

# zfs set mountpoint=/home rpool/home

While performing above command execution I get the error –

# zfs mount -a
cannot mount '/home': directory is not empty

This error may occur due to various reasons like one but not the last is auto mount daemon and so on which I’m not aware of… :)

I got the rid of this pesky issue performing “Overlay mount”

# zfs mount -O rpool/home

BTW then what is overlay mount? – Overlay mount allow the file system to be mounted over an existing mount point, making the underlying file system inaccessible. If a mount is attempted on a pre-existing mount point without setting this flag, the mount will fail, producing the error "device busy" or in ZFS terms “directory is not empty”.

This solution seems to be working just fine for me but I cannot guaranty that same will work for you as I said before there are various factors that leads to such issue.

HTH