What are the file and file system size limitations for Red Hat Enterprise Linux?

Solution Verified - Updated -

Environment

  • Red Hat Enterprise Linux
  • Optional: Global File System version 2 (GFS2) (requires Red Hat Cluster Suite, not supported on a single server)
  • Optional: XFS
  • Filesystem limitation

Issue

  • What are the file and filesystem size limitations for Red Hat Enterprise Linux?
  • Are GFS2 filesystems over 25 TB supported?
  • Is it possible to use ext3 for filesystems 16TB and above on Red Hat Enterprise Linux?
  • I can't create a 20TB filesystem in ext4 or ext3.
  • Is it possible to use ext3 for a very large filesystems (16 TB and above)? If not, which filesystem is recommended for very large filesystems?
  • What is the maximum filesize supported within a filesystem?

Resolution

This following information can be found in the 'File systems and storage limits' section in our Red Hat Enterprise Linux versions comparison chart at: Red Hat Enterprise Linux technology capabilities and limits

Certified and [Maximum] (individual) file size

Filesystem RHEL 3 RHEL 4 RHEL 5 RHEL 6 RHEL 7
EXT2/3 1TiB (3.0) 2TiB (3.5+) 2TiB 2TiB 2TiB 2TiB
EXT4 n/a n/a 16TiB (5.6+)2 16TiB 16TiB
GFS1 2TiB 16TiB [8EiB] 16TiB [8EiB] n/a n/a
GFS2 1 n/a n/a 100TiB (5.3+) [8EiB] 100TiB [8EiB] 100TiB [8EiB]
XFS 3 n/a n/a 100TiB [8EiB] 100TiB [8EiB] 500TiB [8EiB]

Certified and [Maximum] filesystem size

Filesystem RHEL 3 RHEL 4 RHEL 5 RHEL 6 RHEL 7
EXT2/3 1TiB (3.0) 2TiB(3.5+)[8TiB] 8TiB 8TiB (5.0), 16TiB (5.1+) 4 16TiB 16TiB
EXT4 n/a n/a 16TiB [1EiB] (5.6+)2 16TiB [1EiB] 50TiB [1EiB]
GFS 2TiB 16TiB [8EiB] 16TiB [8EiB] n/a n/a
GFS2 1 n/a n/a 100(5.3+)TiB [8EiB] 100TiB [8EiB] 100TiB [8EiB]
XFS 3 n/a n/a 100TiB [16EiB] 100TiB [16EiB] 500TiB [16EiB]

Units

Units are given in binary prefix.

TiB = Tebibyte = 2^40

EiB = Exbibyte = 2^60

Theoretical Limits

The difference between 'certified' and 'maximum' limit is that 'certified' indicates what the file system has been tested to versus what the theoretical maximums are within the code base. For example, GFS2 is a 64-bit based file system and has a theoretical limit of 8EiB, but only filesystems up to the size in the above table have actually been created and tested so that is what is certified. Red Hat will investigate, troubleshoot, and file bugs as needed on larger filesystems. Engineering will make a commercially reasonable effort to fix bugs stemming from usage of filesystems above supported limits. We may rely on customers for testing of patches and confirmation of fixes before rolling them into an official errata. If we cannot test patches which may provide solutions to issues, possible release of related fixes will be delayed.

Notes

[1] The GFS2 filesystem is based on a 64-bit architecture, which can theoretically accommodate an 8 EiB file system. However, the current supported maximum size of a GFS2 file system is 100 TiB. Though we can create large filesystems on GFS2, in Red Hat Enterprise Linux 5.4, the use of the Global File System 2 (GFS2) as a single server file system (i.e. not in a clustered environment) is deprecated.

[2] EXT4 filesystem was a Technology Preview in RHEL 5.3, 5.4 & 5.5. RHEL 5.6 introduced full support for EXT4 as documented in the Release Notes.

[3] The solution for large filesystems is to use XFS. The XFS file system is specifically targeted at very large file systems (16 TiB and above). XFS userland is not be available in the base RHEL channel on RHN, it is provided as a layered product. Although GFS also supports very large file systems, its use is limited to Red Hat Cluster Suite environments. The maximum offset for sparse files of XFS is 8 EiB.

[4] The maximum capacity of the EXT3 is currently 16TiB. This enhancement was originally included in Red Hat Enterprise Linux 5 as a Technology Preview, and fully supported from RHEL 5.1 onward. Prior to this change the maximum capacity available in RHEL 5.0 was 8TiB.

http://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/release-notes/RELEASE-NOTES-U1-x86-en.html

To create filesystems greater than 8 TiB, you may have to invoke mkfs.ext3 with 4K blocks and the -F option:

# mkfs.ext3 -F -b 4096 /dev/BiggerGroup/biggervol

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