Installation guide

Chapter 2. Storage Considerations During Installation
4
File
System
Max
Supported
Size
Max File
Size
Max
Subdirectories
(per
directory)
Max
Depth of
Symbolic
Links
ACL
Support
Details
Ext3 16TB 2TB 32,000 8 Yes Chapter 6,
The Ext3
File System
Ext4 16TB 16TB 65,000
1
8 Yes Chapter 7,
The Ext4
File System
XFS 100TB 16TB 65,000
1
8 Yes Chapter 9,
The XFS
File System
1
When the link count exceeds 65,000, it is reset to 1 and no longer increases.
Note
Not all file systems supported by Red Hat Enterprise Linux 6 are documented in this guide. In
addition, technology preview file systems (e.g. BTRFS) are not documented herein either.
2.3. Special Considerations
This section enumerates several issues and factors to consider for specific storage configurations.
Separate Partitions for /home, /opt, /usr/local
If it is likely that you will upgrade your system in the future, place /home, /opt, and /usr/local on
a separate device. This will allow you to reformat the devices/file systems containing the operating
system while preserving your user and application data.
DASD and zFCP Devices on IBM System Z
On the IBM System Z platform, DASD and zFCP devices are configured via the Channel Command
Word (CCW) mechanism. CCW paths must be explicitly added to the system and then brought online.
For DASD devices, this is simply means listing the device numbers (or device number ranges) as the
DASD= parameter at the boot command line or in a CMS configuration file.
For zFCP devices, you must list the device number, logical unit number (LUN), and world wide port
name (WWPN). Once the zFCP device is initialized, it is mapped to a CCW path. The FCP_x= lines
on the boot command line (or in a CMS configuration file) allow you to specify this information for the
installer.
Encrypting Block Devices Using LUKS
Formatting a block device for encryption using LUKS/dm-crypt will destroy any existing formatting
on that device. As such, you should decide which devices to encrypt (if any) before the new system's
storage configuration is activated as part of the installation process.
Stale BIOS RAID Metadata
Moving a disk from a system configured for firmware RAID without removing the RAID metadata from
the disk can prevent Anaconda from correctly detecting the disk.