This chapter describes how to use delegated administration to allow non-privileged users to perform ZFS administration tasks.Overview of ZFS Delegated Administration Delegating ZFS Permissions Displaying ZFS Delegated Permissions (Examples) Delegating ZFS Permissions (Examples) Removing ZFS Permission (Examples) This feature enables you to distribute fine-grained permissions to specific users, groups, or everyone. Two styles of delegated permissions are supported:Individual permissions can be explicitly specified such a create, destroy, mount and snapshot, and so on. Groups of permissions called permission sets can be defined. A permission set can later be updated and all of the consumers of the set automatically pick up the change. Permission sets begin with the @ letter and are limited to 64 characters in length. After the @ character, the remaining characters in the set name have the same restrictions as normal ZFS file system names. ZFS delegated administration provides similar features to the RBAC security. However, ZFS delegated administration provides the following advantages for administering ZFS storage pools and file systems:Permissions follow the ZFS storage pool when the pool is migrated. Provides dynamic inheritance and you can control how the permissions propagate through the file systems. Can be configured so that only the creator of a file system can destroy the file systems they create. Permissions can be distributed to specific file systems. Newly created file systems can automatically pick up permissions. Provides simple NFS administration. For example, a user with explicit permissions could create a snapshot over NFS in the appropriate .zfs/snapshot directory. Consider using delegated administration for distributing ZFS tasks. For information about using RBAC to manage general Solaris administration tasks, see Part III, Roles, Rights Profiles, and Privileges, in System Administration Guide: Security Services.You can modify the ability to use delegated administration with the pool's delegation property. For example:# zpool get delegation users NAME PROPERTY VALUE SOURCE users delegation on default # zpool set delegation=off users # zpool get delegation users NAME PROPERTY VALUE SOURCE users delegation off localBy default, the delegation property is enabled. You can use the zfs allow command to grant permissions on ZFS datasets to non-root users in the following ways:Individual permissions can be granted to a user, group, or everyone. Groups of individual permissions can be granted as a permission set to a user, group, or everyone. Permissions can be granted either locally, which is to the current dataset only, or granted to all descendents of the current dataset. The following table describes the operations that can be delegated and any dependent permissions that are required to do the delegated operations.Permission (Subcommand) Description Dependencies allow The ability to grant permissions that you have to another user. Must also have the permission that is being allowed. clone The ability to clone any of the dataset's snapshots. Must also have the create ability and the mount ability in the origin file system. create The ability to create descendent datasets. Must also have the mount ability. destroy The ability to destroy a dataset. Must also have the mount ability. mount The ability to mount and unmount a dataset and create and destroy volume device links. promote The ability to promote a clone to a dataset. Must also have the mount ability and promote ability in the origin file system. receive The ability to create descendent file system with the zfs receivecommand. Must also have the mount ability and the create ability. rename The ability to rename a dataset. Must also have the mount ability and the create ability in the new parent. rollback The ability to rollback a snapshot. Must also have the mount ability. send The ability to send a snapshot stream. share The ability to share and unshare a dataset. snapshot The ability to take a snapshot of a dataset. In addition, you can delegate the following ZFS properties to non-root users:aclinherit aclmode atime canmount casesensitivity checksum compression copies exec devices mountpoint nbmand normalization quota readonly recordsize reservation setuid shareiscsi sharenfs sharesmb snapdir userprop utf8only version volsize vscan xattr zoned Some of the properties listed above can only set at dataset creation time. For a description of these properties, see Introducing ZFS Properties.The zfs allow syntax is as follows:# zfs allow -[l d u g e c s] everyone|user|group[,,...] perm|@setname ,...] filesystem| volumeThe following zfs allow syntax (in bold) identifies to whom the permissions are delegated:zfs allow [-uge] | user | group | everyone [,...] filesystem | volumeMultiple entities can be specified as a comma-separated list. If none of the uge options are specified, then the argument is interpreted preferentially as the keyword everyone, then as a user name, and lastly, as a group name. To specify a user or group named “everyone,” use the u or g options. To specify a group with the same name as a user, use the g option.The following zfs allow syntax (in bold) identifies how permissions and permission sets are specified:zfs allow [-s] ... perm | @setname [,...] filesystem | volumeMultiple permissions can be specified as a comma-separated list. Permission names are the same as ZFS subcommands and properties. For more information, see the section above.Permissions can be aggregated into permissions sets and are identified by the s option. Permission sets can be used by other zfs allow commands for the specified file system and its descendents. Sets are evaluated dynamically, so changes to a set are immediately updated. Permission sets follow the same naming conventions as ZFS file systems, but the name must begin with an at sign (@), and can be no more than 64 characters long.The following zfs allow syntax (in bold) identifies how the permissions are delegated:zfs allow [-ld] ... ... filesystem | volumeThe l option identifies if whether the permission is allowed for the specified dataset and not its descendents, unless the d option is also specified. The d option indicates that the permission is allowed for the descendent datasets and not for this dataset, unless the l option is also specified. If neither of the ld options are specified, then the permissions are allowed for the file system or volume and all of its descendents. You can remove previously granted permissions with the zfs unallow command.For example, if you delegated create, destroy, mount, and snapshot permissions as follows:# zfs allow cindys, create,destroy,mount,snapshot tank/cindys # zfs allow tank/cindys ------------------------------------------------------------- Local+Descendent permissions on (tank/cindys) user cindys create,destroy,mount,snapshot -------------------------------------------------------------You would need to use syntax similar to the following to remove these permissions:# zfs unallow cindys tank/cindys # zfs allow tank/cindys This section provides examples of displaying and delegating permissions.You can use the following command to display permissions:# zfs allow datasetThe above command prints permissions that are set or allowed on this dataset. The output contains the following components:Permissions sets Specific permissions or create time permissions Local Local and descendent Descendent only The following example output indicates that user cindys has permission to create, destroy, mount, snapshot in the tank/cindys file system.# zfs allow tank/cindys ------------------------------------------------------------- Local+Descendent permissions on (tank/cindys) user cindys create,destroy,mount,snapshot The following example output indicates the following permissions on the pool and pool/fred file systems.For the pool/fred file system:Two permission sets are defined:@eng (create, destroy, snapshot, mount, clone, promote, rename) @simple (create, mount) Create time permissions are set for the @eng permission set and the mountpoint property. Create time means that after a dataset set is created, the @eng permission set and the mountpoint property are granted. User tom is granted the @eng permission set and the user joe is granted create, destroy, mount permissions for local file systems. User fred is granted the @basic permission set and share and rename permissions for the local and descendent file systems. User barney is granted the @basic permission set for descendent file systems only. For the pool file system:The permission set @simple (create, destroy, mount) is defined. The group staff is granted the @simple permission set on the local file system. $ zfs allow pool/fred ------------------------------------------------------------------------------ Permission sets on (pool/fred) @eng create,destroy,snapshot,mount,clone,promote,rename @simple create,mount Create time permissions on (pool/fred) @eng,mountpoint Local permissions on (pool/fred) user tom @eng user joe create,destroy,mount Local+Descendent permissions on (pool/fred) user fred @basic,share,rename Descendent permissions on (pool/fred) user barney @basic group staff @basic ------------------------------------------------------------------------------ Permission sets on (pool) @simple create,destroy,mount Local permissions on (pool) group staff @simple ------------------------------------------------------------------------------ When you provide create and mount permissions, you need to make sure that the user has permissions on the underlying mount point.For example, to give marks create and mount permissions on tank, set the permissions first:# chmod A+user:marks:add_subdirectory:fd:allow /tankThen, use the zfs allow to grant create, destroy, and mount permissions. For example:# zfs allow marks create,destroy,mount tankThis means that marks can create his own file systems in the tank file system. For example:# su marks marks$ zfs create tank/marks marks$ ^D # su lp $ zfs create tank/lp cannot create 'tank/lp': permission denied The following example shows how to set up a file system so that anyone in the staff group can create and mount file systems in the tank file system, and also allows them to destroy their own file systems. However, staff group members cannot destroy anyone else's file systems.# zfs allow staff create,mount tank # zfs allow -c create,destroy tank # zfs allow tank ------------------------------------------------------------- Create time permissions on (tank) create,destroy Local+Descendent permissions on (tank) group staff create,mount ------------------------------------------------------------- # su cindys cindys% zfs create tank/cindys cindys% exit # su marks marks% zfs create tank/marks/data marks% exit cindys% zfs destroy tank/marks/data cannot destroy 'tank/mark': permission denied Make sure to grant users permission at the right file system level. User marks is granted create, destroy, and mount permissions for the local and descendent file systems. User marks is granted local permission to snapshot the tank file system, but this does not allow him to snapshot his own file system. # zfs allow -l marks snapshot tank # zfs allow tank ------------------------------------------------------------- Local permissions on (tank) user marks snapshot Local+Descendent permissions on (tank) user marks create,destroy,mount ------------------------------------------------------------- # su marks marks$ zfs snapshot tank/@snap1 marks$ zfs snapshot tank/marks@snap1 cannot create snapshot 'mark/marks@snap1': permission deniedUse the zfs allow d option to grant marks permission at the descendent level. For example:# zfs unallow -l marks snapshot tank # zfs allow -d marks snapshot tank # zfs allow tank ------------------------------------------------------------- Descendent permissions on (tank) user marks snapshot Local+Descendent permissions on (tank) user marks create,destroy,mount ------------------------------------------------------------- # su marks $ zfs snapshot tank@snap2 cannot create snapshot 'sandbox@snap2': permission denied $ zfs snapshot tank/marks@snappyUser marks can only create a snapshot below the tank level. You can grant specific permissions to users or groups. For example, the following zfs allow command grants specific permissions to the staff group. In addition, destroy and snapshot permissions are granted after tank file systems are created.# zfs allow staff create,mount tank # zfs allow tank ------------------------------------------------------------- Create time permissions on (tank) destroy,snapshot Local+Descendent permissions on (tank) group staff create -------------------------------------------------------------Because marks is a member of the staff group, he can create file systems in tank. In addition, user marks can create a snapshot of tank/marks2 because he has specific permissions. For example:# su marks $ zfs create tank/marks2 $ zfs allow tank/marks2 ------------------------------------------------------------- Local permissions on (tank/marks2) user marks destroy,snapshot ------------------------------------------------------------- Create time permissions on (tank) destroy,snapshot Local+Descendent permissions on (tank) group staff create everyone mount -------------------------------------------------------------But, he can't create a snapshot in tank/marks because he doesn't have specific permissions. See the listing above. For example:$ zfs snapshot tank/marks2@snap1 $ zfs snapshot tank/marks@snappp cannot create snapshot 'tank/marks@snappp': permission deniedYou can create snapshot directories if you have create permission in your home directory, for example. This is helpful when your file system is NFS mounted. For example:$ cd /tank/marks2 $ ls $ cd .zfs $ ls snapshot $ cd snapshot $ ls -l total 3 drwxr-xr-x 2 marks staff 2 Dec 15 13:53 snap1 $ pwd /tank/marks2/.zfs/snapshot $ mkdir snap2 $ zfs list NAME USED AVAIL REFER MOUNTPOINT tank 264K 33.2G 33.5K /tank tank/marks 24.5K 33.2G 24.5K /tank/marks tank/marks2 46K 33.2G 24.5K /tank/marks2 tank/marks2@snap1 21.5K - 24.5K - tank/marks2@snap2 0 - 24.5K - $ ls snap1 snap2 $ rmdir snap2 $ ls snap1 The following example creates a permission set @myset and grants the permission set and the rename permission to the group staff for the tank file system. User cindys, a group staff member, has the ability to create a file system in tank but user lp has no permission to create a file system in tank.# zfs allow -s @myset create,destroy,mount,snapshot,promote,clone,readonly tank # zfs allow tank ------------------------------------------------------------- Permission sets on (tank) @myset clone,create,destroy,mount,promote,readonly,snapshot ------------------------------------------------------------- # zfs allow staff @myset,rename tank # zfs allow tank ------------------------------------------------------------- Permission sets on (tank) @myset clone,create,destroy,mount,promote,readonly,snapshot Local+Descendent permissions on (tank) group staff @myset,rename # chmod A+group:staff:add_subdirectory:fd:allow tank # su cindys cindys% zfs create tank/data Cindys% zfs allow tank ------------------------------------------------------------- Permission sets on (tank) @myset clone,create,destroy,mount,promote,readonly,snapshot Local+Descendent permissions on (tank) group staff @myset,rename ------------------------------------------------------------- cindys% ls -l /tank total 15 drwxr-xr-x 2 cindys staff 2 Aug 8 14:10 data cindys% exit # su lp $ zfs create tank/lp cannot create 'tank/lp': permission denied You can use the following command to remove granted permissions. For example, user cindys has permission to create, mount, destroy, and snapshot in the tank/cindys file system.# zfs allow cindys create,destroy,mount,snapshot tank/cindys # zfs allow tank/cindys ------------------------------------------------------------- Local+Descendent permissions on (tank/cindys) user cindys create,destroy,mount,snapshot -------------------------------------------------------------This zfs unallow syntax removes user cindys's snapshot permission from the tank/cindys file system.# zfs unallow cindys snapshot tank/cindys # zfs allow tank/cindys ------------------------------------------------------------- Local+Descendent permissions on (tank/cindys) user cindys create,destroy,mount ------------------------------------------------------------- cindys% zfs create tank/cindys/data cindys% zfs snapshot tank/cindys@today cannot create snapshot 'tank/cindys@today': permission deniedUser marks has the following permissions in tank/marks.# zfs allow tank/marks ------------------------------------------------------------- Local+Descendent permissions on (tank/marks) user marks create,destroy,mount -------------------------------------------------------------The following zfs unallow syntax removes all permissions for user marks from tank/marks.# zfs unallow marks tank/marksThe following zfs unallow syntax removes a permission set on the tank file system.# zfs allow tank ------------------------------------------------------------- Permission sets on (tank) @myset clone,create,destroy,mount,promote,readonly,snapshot Create time permissions on (tank) create,destroy,mount Local+Descendent permissions on (tank) group staff create,mount ------------------------------------------------------------- # zfs unallow -s @myset tank $ zfs allow tank ------------------------------------------------------------- Create time permissions on (tank) create,destroy,mount Local+Descendent permissions on (tank) group staff create,mount -------------------------------------------------------------