---
title: "File system"
source: https://dev.pageseeder.com/reference/glossary/file_system.html
last_updated: 2026-08-07T17:09:54+10:00
tokens: ~711
---

# File system

PageSeeder relies on the file system to store documents and binary files. For information about files managed by PageSeeder, *see* [folders and files](../folders_and_files.md).

## Common file systems

The following table summarizes the important features and limitations of common file systems:

|  | Linux | Windows | MacOS |
| --- | --- | --- | --- |
|  | Ext3 | Ext4 | FAT32 | NTFS | HFS + |
| Max volume size | 4 Tib-32 Tib | 1 EiB | 32 Gib | 16 EiB | 8 EiB |
| Max file size | 16 Gib-2 Tib | 16 Tib | 4 Gib | 16 EiB | 8 EiB |
| Max filename length | 255 bytes | 255 UTF-16 characters  |
| Max pathname length | 4,096 bytes | 32,760 UTF-16 characters |  |
| Allowed chars in filenames | All bytes (except NUL) | Any Unicode character (except NUL and '/') | Any Unicode character (including NUL) |
| Directories | 31998 | unlimited |  |  |  |
| Max number of files | Depends on volume size | 4 billion | 2<sup>64</sup>-1 | 2<sup>32</sup>-1 |
| Case sensitive | Yes | Yes | No | Optional - OS prevents same case-insensitive name in a directory |
| Case preserving | Yes | Yes | Yes | Yes | Yes |

> **Note:** Note that additional limitations are imposed by the operating system.

## Other file systems

The following file systems are used for external storage devices such as USB keys, SD cards, DVD and CD-ROM.

|  | UDF | exFAT |
| --- | --- | --- |
| Max volume size | 2 TB | 128 PiB |
| Max file size | 16 EB | 128 PiB |
| Max filename length | 255 bytes | 255 UTF-16 characters |
| Max pathname length | 1023 bytes |  |
| Allowed chars in filenames | Any Unicode except NUL | Unicode UTF-16 except: +0000 (NUL) through U+001F/ (slash)\\ (backslash): (colon)\* (asterisk)? (Question mark)" (quote)\< (less than)\> (greater than)\| (pipe) |
| Max files in directories |  | 2,796,202 |
| Max number of files |  |  |
| Reserved file names |  |  |

## Operating system limits

Operating systems impose additional limits to the file system. Most use Unicode in practice.

### Linux

- Unicode support by default using UTF-8 encoding.
- File names starting with a ‘.’ are hidden.

### Microsoft Windows

- Unicode using by default UTF-16 encoding.
- Reserved characters in filenames: 


  - U+0000 (NUL) through to U+0031.
  - \< (less than).
  - \> (greater than).
  - : (colon).
  - " (double quote).
  - / (forward slash).
  - \\ (backslash).
  - | (vertical bar or pipe).
  - ? (question mark).
  - \* (asterisk).
- Reserved file names: 


  - CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9.
  - Use of filename even with an extension (e.g. NUL.txt) is not recommended.
  - File names shouldn’t end with a ‘.’ or ‘ ’ (space).

## MacOS

- Unicode using by default UTF-16 encoding.
- Reserved characters: 


  - : (colon).
  - / (slash).