1. Introduction — TrueNAS®11.0-U4 User Guide Table of Contents

Copyright iXsystems 2011-2017

TrueNAS® and the TrueNAS® logo are registered trademarks of iXsystems.

Welcome to the TrueNAS® User Guide.

TrueNAS® and the TrueNAS® logo are registered trademarks of iXsystems.

Active Directory® is a registered trademark or trademark of Microsoft Corporation in the United States and/or other countries.

Apple, Mac and Mac OS are trademarks of Apple Inc., registered in the U.S. and other countries.

Avago is a trademark of Avago Technologies.

Chelsio® is a registered trademark of Chelsio Communications.

Cisco® is a registered trademark or trademark of Cisco Systems, Inc. and/or its affiliates in the United States and certain other countries.

FreeBSD® and the FreeBSD® logo are registered trademarks of the FreeBSD Foundation®.

Linux® is a registered trademark of Linus Torvalds.

Oracle is a registered trademark of Oracle Corporation and/or its affiliates.

UNIX® is a registered trademark of The Open Group.

VMware® is a registered trademark of VMware, Inc.

Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.

Windows® is a registered trademark of Microsoft Corporation in the United States and other countries.

Typographic Conventions

The TrueNAS® Administrator Guide uses these typographic conventions:

Table 1 Text Format Examples
Item | Visual Example
--- | ---
Graphical elements: buttons, icons, fields, columns, and boxes | Click the Import CA button.
Menu selections | Select `System → Information`.
Commands | Use the scp command.
File names and volume and dataset names | Locate the `/etc/rc.conf` file.
Keyboard keys | Press the `Enter` key.
Important points | This is important.
Values entered into fields, or device names | Enter 127.0.0.1 in the address field.

# 1. Introduction

This Guide provides information about configuring and managing the TrueNAS® Unified Storage Array. Your iXsystems support engineer will assist with the initial setup and configuration of the array. After becoming familiar with the configuration workflow, this document can be used as a reference guide to the many features provided by TrueNAS®.

## 1.1. Path and Name Lengths

Names of files, directories, and devices are subject to some limits imposed by the FreeBSD operating system. The limits shown here are for names using plain-text characters that each occupy one byte of space. Some UTF-8 characters take more than a single byte of space, and using those characters reduces these limits proportionally. System overhead can also reduce the length of these limits by one or more bytes.

Table 1.1.1 Path and Name Lengths
Type | Maximum Length | Description
--- | --- | ---
File Paths | 1024 bytes | Total file path length (PATH_MAX). The full path includes directory separator slash characters, subdirectory names, and the name of the file itself. For example, the path `/mnt/tank/mydataset/mydirectory/myfile.txt` is 42 bytes long. Using very long file or directory names can be problematic. A complete path with long directory and file names can exceed the 1024-byte limit, preventing direct access to that file until the directory names or filename are shortened or the file is moved into a directory with a shorter total path length.
File and Directory Names | 255 bytes | Individual directory or file name length (NAME_MAX).
Mounted Filesystem Paths | 88 bytes | Mounted filesystem path length (MNAMELEN). Longer paths can prevent a device from being mounted.
Device Filesystem Paths | 63 bytes | devfs(8) device path lengths (SPECNAMELEN). Longer paths can prevent a device from being created.