ZFS Command Improvements and Changes (Solaris 10 7/07 HW What's New)

Solaris 10 7/07 HW What's New

ZFS Command Improvements and Changes

The following section summarizes new features in the Solaris^TM ZFS file system. For more information about these new features, see the Solaris ZFS Administration Guide.

ZFS command history (zpool history) – Starting with the Solaris 10 7/07 HW release, ZFS automatically logs successful zfs and zpool commands that modify pool state information. This feature enables you or Sun support personnel to identify the exact set of ZFS commands that was executed to troubleshoot an error scenario.
Improved storage pool status information (zpool status) – Starting with the Solaris 10 7/07 HW release, you can use the zpool status -v command to display a list of files with persistent errors. Previously, you had to use the find -inum command to identify the filenames from the list of displayed inodes.

ZFS and Solaris iSCSI improvements – Starting with the Solaris 10 7/07 HW release, you can create a ZFS volume as a Solaris iSCSI target device by setting the shareiscsi property on the ZFS volume. This method is a convenient way to quickly set up a Solaris iSCSI target. For example:

# zfs create -V 2g tank/volumes/v2
# zfs set shareiscsi=on tank/volumes/v2
# iscsitadm list target
Target: tank/volumes/v2
     iSCSI Name: iqn.1986-03.com.sun:02:984fe301-c412-ccc1-cc80-cf9a72aa062a
     Connections: 0

After the iSCSI target is created, set up the iSCSI initiator. For information about setting up a Solaris iSCSI initiator, see Chapter 14, Configuring Solaris iSCSI Targets and Initiators (Tasks), in System Administration Guide: Devices and File Systems.

For more information about managing a ZFS volume as an iSCSI target, see the Solaris ZFS Administration Guide.

ZFS property improvements
- ZFS xattr property – Starting with the Solaris 10 7/07 HW release, you can use the xattr property to disable or enable extended attributes for a specific ZFS file system. The default value is on.
- ZFS canmount property – Starting with the Solaris 10 7/07 HW release, you use the canmount property to specify whether a dataset can be mounted by using the zfs mount command.
- ZFS user properties – Starting with the Solaris 10 7/07 HW release, ZFS supports user properties, in addition to the standard native properties that can either export internal statistics or control ZFS file system behavior. User properties have no effect on ZFS behavior, but you can use them to annotate datasets with information that is meaningful in your environment.
- Setting properties when creating ZFS file systems – Starting with the Solaris 10 7/07 HW release, you can set properties when you create a file system, in addition to setting properties after the file system is created.
  
  The following examples illustrate equivalent syntax:
  # zfs create tank/home # zfs set mountpoint=/export/zfs tank/home # zfs set sharenfs=on tank/home # zfs set compression=on tank/home
  # zfs create -o mountpoint=/export/zfs -o sharenfs=on -o compression=on tank/home

Display all ZFS file system information – Starting with the Solaris 10 7/07 HW, you can use various forms of the zfs get command to display information about all datasets if you do not specify a dataset. In releases prior to the current release, all dataset information was not retrievable with the zfs get command. For example:

# zfs get -s local all
tank/home               atime          off                    local
tank/home/bonwick       atime          off                    local
tank/home/marks         quota          50G                    local

New zfs receive -F option – Starting with the Solaris 10 7/07 HW, you can use the new -F option to the zfs receive command to force a rollback of the file system to the most recent snapshot before doing the receive. Using this option might be necessary when the file system is modified between the time a rollback occurs and the receive is initiated.
Recursive ZFS snapshots – Starting with the Solaris 10 11/06 release, recursive snapshots are available. When you use the zfs snapshot command to create a file system snapshot, you can use the -r option to recursively create snapshots for all descendant file systems. In addition, using the -r option recursively destroys all descendant snapshots when a snapshot is destroyed.
Double Parity RAID-Z (raidz2) – Starting with the Solaris 10 11/06 release, replicated RAID-Z configuration can now have either single- or double-parity, which means that one or two device failures can be sustained respectively, without any data loss. You can specify the raidz2 keyword for a double-parity RAID-Z configuration. Or, you can specify the raidz or raidz1 keyword for a single-parity RAID-Z configuration.
Hot spares for ZFS storage pool devices – Starting with the Solaris 10 11/06 release, the ZFS hot spares feature enables you to identify disks that could be used to replace a failed or faulted device in one or more storage pools. Designating a device as a hot spare means that if an active device in the pool fails, the hot spare automatically replaces the failed device. Or, you can manually replace a device in a storage pool with a hot spare.
Replacing a ZFS file system with a ZFS clone (zfs promote) – Starting with the Solaris 10 11/06 release, the zfs promote command enables you to replace an existing ZFS file system with a clone of that file system. This feature is helpful when you want to run tests on an alternative version of a file system and then, make that alternative version of the file system the active file system.
ZFS and zones improvements – Starting with the Solaris 10 11/06 release, the ZFS and zones interaction is improved. On a Solaris system with zones installed, you can use the zoneadm clone feature to copy the data from an existing source ZFS zonepath to a target ZFS zonepath on your system. You cannot use the ZFS clone feature to clone the non-global zone. You must use the zoneadm clone command. For more information, see System Administration Guide: Solaris Containers-Resource Management and Solaris Zones.
Upgrading ZFS storage pools (zpool upgrade) – Starting with the Solaris 10 6/06 release, you can upgrade your storage pools to a newer version to take advantage of the latest features by using the zpool upgrade command. In addition, the zpool status command has been modified to notify you when your pools are running older versions.
Clearing device errors – Starting with the Solaris 10 6/06 release, you can use the zpool clear command to clear error counts associated with a device or the pool. Previously, error counts were cleared when a device in a pool was brought online with the zpool online command.
Recovering destroyed pools – Starting with the Solaris 10 6/06 release, the zpool import -D command enables you to recover pools that were previously destroyed with the zpool destroy command.
ZFS backup and restore commands are renamed – Starting with the Solaris 10 6/06 release, the zfs backup and zfs restore commands are renamed to zfs send and zfs receive to more accurately describe their function. The function of these commands is to save and restore ZFS data stream representations.
Compact NFSv4 ACL format – Starting with the Solaris 10 6/06 release, three NFSv4 ACL formats are available: verbose, positional, and compact. The new compact and positional ACL formats are available to set and display ACLs. You can use the chmod command to set all 3 ACL formats. Use the ls -V command to display compact and positional ACL formats and the ls -v command to display verbose ACL formats.
Temporarily take a device offline – Starting with the Solaris 10 6/06 release, you can use the zpool offline -t command to take a device offline temporarily. When the system is rebooted, the device is automatically returned to the ONLINE state.
ZFS is integrated with Fault Manager – Starting with the Solaris 10 6/06 release, a ZFS diagnostic engine is included that is capable of diagnosing and reporting pool failures and device failures. Checksum, I/O, and device errors associated with pool or device failures are also reported. Diagnostic error information is written to the console and the /var/adm/messages file. In addition, detailed information about recovering from a reported error can be displayed by using the zpool status command.

For more information about these improvements and changes, see the Solaris ZFS Administration Guide.

See the following What's New sections for related ZFS feature information: