* Moving files or directories between directories on a SMB share fail with IO errors.
* Moving files or directories between directories on a SMB share fail with IO errors.
This isn't an issue with Samba but some SMB clients. GVFS-fuse v1.20.3 and prior (found in Ubuntu 14.04 among others) failed to handle certain error codes correctly. Particularly **EXDEV** which is returned by **rename** when the call is crossing mountpoints. When a program gets an **EXDEV** it needs to explicitly take an alternate action to accomplish it's goal. In the case of **mv** or similar it tries **rename** and on **EXDEV** falls back to a manual copying of data between the two locations and unlinking the source. In these older versions of GVFS-fuse if it received **EXDEV** it would translate that into **EIO**. This would cause **mv** or most any application attempting to move files around on that SMB share to fail with a IO error.
Workaround: Copy the file/directory and then remove the original rather than move.
[GVFS-fuse v1.22.0](https://bugzilla.gnome.org/show_bug.cgi?id=734568) and above fixed this issue but a large number of systems use the older release. On Ubuntu the version can be checked by issuing `apt-cache showpkg gvfs-fuse`. Most distros released in 2015 seem to have the updated release and will work fine but older systems may not. Upgrading gvfs-fuse or the distro in general will address the problem.
This isn't an issue with Samba but some SMB clients. GVFS-fuse v1.20.3 and prior (found in Ubuntu 14.04 among others) failed to handle certain error codes correctly. Particularly **STATUS_NOT_SAME_DEVICE** which comes from the **EXDEV** which is returned by **rename** when the call is crossing mountpoints. When a program gets an **EXDEV** it needs to explicitly take an alternate action to accomplish it's goal. In the case of **mv** or similar it tries **rename** and on **EXDEV** falls back to a manual copying of data between the two locations and unlinking the source. In these older versions of GVFS-fuse if it received **EXDEV** it would translate that into **EIO**. This would cause **mv** or most any application attempting to move files around on that SMB share to fail with a IO error.
Interestingly it appears that OSX is similary affected but it is not yet known why or if there are any workarounds. Windows 7, Windows 8.1, Windows 10, and ChromeOS all work fine.
[GVFS-fuse v1.22.0](https://bugzilla.gnome.org/show_bug.cgi?id=734568) and above fixed this issue but a large number of systems use the older release. On Ubuntu the version can be checked by issuing `apt-cache showpkg gvfs-fuse`. Most distros released in 2015 seem to have the updated release and will work fine but older systems may not. Upgrading gvfs-fuse or the distro in general will address the problem.
In Apple's MacOSX 10.9 they replaced Samba (client and server) with their own product. It appears their new client does not handle **EXDEV** either and responds similar to older release of gvfs on Linux.
#### Supplemental groups
#### Supplemental groups
* Due to the overhead of [getgroups/setgroups](http://linux.die.net/man/2/setgroups) mergerfs utilizes a cache. This cache is opportunistic and per thread. Each thread will query the supplemental groups for a user when that particular thread needs to change credentials and will keep that data for the lifetime of the mount or thread. This means that if a user is added to a group it may not be picked up without the restart of mergerfs. However, since the high level FUSE API's (at least the standard version) thread pool dynamically grows and shrinks it's possible that over time a thread will be killed and later a new thread with no cache will start and query the new data.
* Due to the overhead of [getgroups/setgroups](http://linux.die.net/man/2/setgroups) mergerfs utilizes a cache. This cache is opportunistic and per thread. Each thread will query the supplemental groups for a user when that particular thread needs to change credentials and will keep that data for the lifetime of the mount or thread. This means that if a user is added to a group it may not be picked up without the restart of mergerfs. However, since the high level FUSE API's (at least the standard version) thread pool dynamically grows and shrinks it's possible that over time a thread will be killed and later a new thread with no cache will start and query the new data.
Antonio SJ Musumeci
9 years ago