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Oracle® ZFS Storage Appliance Administration Guide
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Document Information

Using This Documentation

Chapter 1 Oracle ZFS Storage Appliance Overview

Chapter 2 Status

Chapter 3 Initial Configuration

Chapter 4 Network Configuration

Chapter 5 Storage Configuration

Chapter 6 Storage Area Network Configuration

Chapter 7 User Configuration

Chapter 8 Setting ZFSSA Preferences

Chapter 9 Alert Configuration

Chapter 10 Cluster Configuration

Chapter 11 ZFSSA Services

Chapter 12 Shares, Projects, and Schema

Understanding Shares

Storage Pools

Using Shares

Share Properties

Share Snapshots

Share Clones

Shares Space Management

Shares Space Terminology

Understanding Snapshots

File System and Project Settings

Data Quotas

Data Reservations

Space Management for Replicating LUNs

User and Group Settings

Viewing Current Usage

Viewing Current Usage in the BUI

Viewing Current Usage in the CLI

Setting User or Group Quotas

Set User or Group Quotas Using the BUI

Set User or Group Quotas Using the CLI

Identity Management

Filesystem Namespace

Namespace Nested Mountpoints

Namespace Protocol Access to Mountpoints

Namespace NFSv2 / NFSv3

Namespace NFSv4

Namespace SMB

Namespace FTP / FTPS / SFTP

Namespace HTTP / HTTPS

Shares > Shares

Working with Shares > Shares in the BUI

List of Shares

Editing a Share

Usage Statistics

Static Properties

Shares Project Panel

Creating a Share

Working with Shares > Shares in the CLI

Navigation

Share Operations

Shares > Shares CLI Properties

Shares > Shares > General - BUI Page

Space Usage

Volume Size

Thin Provisioned

Mountpoint

Read only

Update access time on read

Non-blocking mandatory locking

Data deduplication

Data compression

Checksum

Cache Device Usage

Synchronous Write Bias

Database Record Size

Additional Replication

Virus Scan

Prevent Destruction

Restrict Ownership Change

Custom Properties

Shares > Shares > Protocols - BUI Page

Shares Protocols

Share Protocols - NFS

Share Protocols - CLI

Security Modes

Character Set Encodings

Shares - SMB

Shares - iSCSI

Shares - HTTP

Shares - FTP

Shares - SFTP

Shares > Shares > Access

Access Control

Shares - Root Directory Access

Shares - User

Shares - Group

Shares - Permissions

Shares - ACL Behavior

ACL Behavior on Mode Change

ACL Inheritance Behavior

Root Directory ACL

Shares - Snapshots

Shares - Snapshot Properties

.zfs/snapshot visible

Scheduled Snapshot Label

Listing Snapshots Using the BUI

Manual Snapshots Using the BUI

Create a project level snapshot

Create a share/LUN level snapshot

Renaming a Snapshot (BUI)

Destroying a Snapshot (BUI)

Rolling back to a Snapshot (BUI)

Cloning a Snapshot (BUI)

Scheduled Snapshots Using the BUI

Manual Snapshots Using the CLI

Listing Snapshots (CLI)

Taking Manual Snapshots (CLI)

Renaming a Snapshot (CLI)

Destroying a Snapshot (CLI)

Rolling back to a Snapshot (CLI)

Cloning a Snapshot (CLI)

Listing Dependent Clones Using the CLI

Scheduled Snapshots Using the CLI

Setting the Scheduled Snapshot Label Using the CLI

Projects

Working with Projects Using the BUI

Project Fields

Editing a Project

Usage Statistics

Static Properties

Creating Projects

Working with Projects Using the CLI

Navigation

Project Operations

Selecting a Pool in a Cluster

Project Properties

Project - General

Project - General Properties

Project - Space Usage

Project - Quota

Project - Reservation

Project - Inherited Properties

Project - Custom Properties

Filesystem Creation Defaults

LUN Creation Defaults

Project Protocols

Project Access

Project Snapshots

Project Snapshot Properites

.zfs/snapshot visible

Scheduled Snapshot Label

Schemas

Customized Share Properties

Working with Schemas in the BUI

Configuring a Schema Using the BUI

Working with Schemas Using the CLI

Configuring a Schema Using the CLI

Chapter 13 Replication

Chapter 14 Shadow Migration

Chapter 15 CLI Scripting

Chapter 16 Maintenance Workflows

Chapter 17 Integration

Index

Synchronous Write Bias

This setting controls the behavior when servicing synchronous writes. By default, the system optimizes synchronous writes for latency, which leverages the log devices to provide fast response times. In a system with multiple disjointed filesystems, this can cause contention on the log devices that can increase latency across all consumers. Even with multiple filesystems requesting synchronous semantics, it may be the case that some filesystems are more latency-sensitive than others.

A common case is a database that has a separate log. The log is extremely latency sensitive, and while the database itself also requires synchronous semantics, it is heavier bandwidth and not latency sensitive. In this environment, setting this property to 'throughput' on the main database while leaving the log filesystem as 'latency' can result in significant performance improvements. This setting will change behavior even when no log devices are present, though the effects may be less dramatic.

The Synchronous write bias setting can be bypassed by the Oracle Intelligent Storage Protocol. Instead of using the write bias defined in the file system, the Oracle Intelligent Storage Protocol can use the write bias value provided by the Oracle Database NFSv4 client. The write bias value sent by the Oracle Database NFSv4 client is used only for that write request. For more information, see Oracle Intelligent Storage Protocol .

BUI value
CLI value
Description
Latency
latency
Synchronous writes are optimized for latency, leveraging the dedicated log device(s), if any.
Throughput
throughput
Synchronous writes are optimized for throughput. Data is written to the primary data disks instead of the log device(s), and the writes are performed in a way that optimizes for total bandwidth of the system.