Chapter 1. Solaris ZFS File System (Introduction)

Table of Contents

What's New in ZFS?
Using ZFS to Clone Non-Global Zones and Other Enhancements
ZFS Backup and Restore Commands are Renamed
Recovering Destroyed Storage Pools
ZFS is Integrated With Fault Manager
New zpool clear Command
Compact NFSv4 ACL Format
File System Monitoring Tool (fsstat)
ZFS Web-Based Management
What Is ZFS?
ZFS Pooled Storage
Transactional Semantics
Checksums and Self-Healing Data
Unparalleled Scalability
ZFS Snapshots
Simplified Administration
ZFS Terminology
ZFS Component Naming Requirements

What's New in ZFS?

This section summarizes new features in the ZFS file system that were added after the initial Solaris Express December 2005 release.

  • Using ZFS to Clone Non-Global Zones and Other Enhancements

  • ZFS Backup and Restore Commands are Renamed

  • Recovering Destroyed Storage Pools

  • ZFS is Integrated With Fault Manager

  • New zpool clear Command

  • Compact NFSv4 ACL Format

  • File System Monitoring Tool (fsstat)

  • ZFS Web-Based Management

Using ZFS to Clone Non-Global Zones and Other Enhancements

OpenSolaris, build 39: When the source zonepath and the target zonepath both reside on ZFS and are in the same pool, zoneadm clone now automatically uses the ZFS clone feature to clone a zone. This enhancement means that zoneadm clone will take a ZFS snapshot of the source zonepath and set up the target zonepath. The snapshot is named SUNWzoneX, where X is a unique ID used to distinguish between multiple snapshots. The destination zone's zonepath is used to name the ZFS clone. A software inventory is performed so that a snapshot used at a future time can be validated by the system. Note that you can still specify that the ZFS zonepath be copied instead of the ZFS clone, if desired.

To clone a source zone multiple times, a new parameter added to zoneadm allows you to specify that an existing snapshot should be used. The system validates that the existing snapshot is usable on the target. Additionally, the zone install process now has the capability to detect when a ZFS file system can be created for a zone, and the uninstall process can detect when a ZFS file system in a zone can be destroyed. These steps are then performed automatically by the zoneadm command.

Do not use the ZFS snapshot features to clone a zone.

For more information, see System Administration Guide: Solaris Containers-Resource Management and Solaris Zones .

ZFS Backup and Restore Commands are Renamed

OpenSolaris, build 38: In this Solaris 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.

For more information about these commands, see Saving and Restoring ZFS Data.

Recovering Destroyed Storage Pools

OpenSolaris, build 37: This release includes the zpool import D command, which enables you to recover pools that were previously destroyed with the zpool destroy command.

For more information, see Recovering Destroyed ZFS Storage Pools.

ZFS is Integrated With Fault Manager

OpenSolaris, build 36: This release includes the integration of a ZFS diagnostic engine that is capable of diagnosing and reporting pool failures and device failures. Checksum, I/O, device, and pool errors associated with pool or device failures are also reported.

The diagnostic engine does not include predictive analysis of checksum and I/O errors, nor does it include proactive actions based on fault analysis.

In the event of the ZFS failure, you might see a message similar to the following from fmd:

SUNW-MSG-ID: ZFS-8000-D3, TYPE: Fault, VER: 1, SEVERITY: Major
EVENT-TIME: Fri Mar 10 11:09:06 MST 2006
PLATFORM: SUNW,Ultra-60, CSN: -, HOSTNAME: neo
SOURCE: zfs-diagnosis, REV: 1.0
EVENT-ID: b55ee13b-cd74-4dff-8aff-ad575c372ef8
DESC: A ZFS device failed.  Refer to http://sun.com/msg/ZFS-8000-D3 for more information.
AUTO-RESPONSE: No automated response will occur.
IMPACT: Fault tolerance of the pool may be compromised.
REC-ACTION: Run 'zpool status -x' and replace the bad device.

By reviewing the recommended action, which will be to follow the more specific directions in the zpool status command, you will be able to quickly identify and resolve the failure.

For an example of recovering from a reported ZFS problem, see Repairing a Missing Device.

New zpool clear Command

OpenSolaris, build 36: This release includes the zpool clear command for clearing 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. For more information, see zpool ( 1M ) and Clearing Storage Pool Devices.

Compact NFSv4 ACL Format

OpenSolaris, build 34: In this 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. You can use the ls V command to display compact and positional ACL formats and the ls v command to display verbose ACL formats.

For more information, see Setting and Displaying ACLs on ZFS Files in Compact Format, chmod ( 1 ) , and ls ( 1 ) .

File System Monitoring Tool (fsstat)

OpenSolaris, build 34: A new file system monitoring tool, fsstat, is available to report file system operations. Activity can be reported by mount point or by file system type. The following example shows general ZFS file system activity.

% fsstat zfs
 new  name   name  attr  attr lookup rddir  read read  write write
 file remov  chng   get   set    ops   ops   ops bytes   ops bytes
 729K  488K  282K 79.8M  266K   333M 5.33M 24.8M  115G 2.36M 27.8G zfs

For more information, see fsstat ( 1M ) .

ZFS Web-Based Management

OpenSolaris, build 28: A web-based ZFS management tool is available to perform many administrative actions. With this tool, you can perform the following tasks:

  • Create a new storage pool.

  • Add capacity to an existing pool.

  • Move (export) a storage pool to another system.

  • Import a previously exported storage pool to make it available on another system.

  • View information about storage pools.

  • Create a file system.

  • Create a volume.

  • Take a snapshot of a file system or a volume.

  • Roll back a file system to a previous snapshot.

You can access the ZFS Administration console through a secure web browser at the following URL:

https://system-name:6789/zfs

If you type the appropriate URL and are unable to reach the ZFS Administration console, the server might not be started. To start the server, run the following command:

# /usr/sbin/smcwebserver start

If you want the server to run automatically when the system boots, run the following command:

# /usr/sbin/smcwebserver enable