Red Hat Enterprise Linux 6 technology capabilities and limits

Supported and theoretical

What can Red Hat® Enterprise Linux® do? Find out in this quick-glance chart of the supported and theoretical[1] limits of the platform.

See also:

 

Version 3

Version 4

Version 5

Version 6
Maximum logical CPUs [2]        
x86 16 32 32 32
Itanium 2 8 256/512 256/1024 N/A[6]
x86_64 8 64/64 160/255 160/4096
POWER 8 64/128 128/128 128
System z 64 (z900) 64 (z10 EC) 101 (zEC12) 101 (zEC12)
Maximum memory[5]        
x86 64GB[3] 64GB[3] 16GB[4] 16GB[4]
Itanium 2 128GB 2TB 2TB N/A[6]
x86_64 128GB 256GB/1TB 1TB 3TB/64TB
POWER 64GB 128GB/1TB 512GB/1TB 2TB
System z 256GB (z900) 1.5TB (z10 EC) 3TB (z196) 3TB (z196)
Required minimums        
x86 256MB 256MB 512MB minimum/
1 GB/logical CPU recommended		 512MB minimum/
1 GB/logical CPU recommended
x86_64 256MB 256MB 512MB minimum/
1 GB/logical CPU recommended		 1GB minimum/
1 GB/logical CPU recommended
Itanium 2 512MB 512MB 512MB/
1 GB/logical CPU recommended		 N/A[6]
POWER 512MB 512MB 1GB minimum/
2GB recommended		 2GB minimum/
2GB required per install
Minimum diskspace 800MB 800MB 1GB minimum/
5GB recommended		 1GB minimum/
5GB recommended
File systems and storage limits        
Maximum filesize (Ext3) 2TB 2TB 2TB 2TB
Maximum file system size (Ext3) 2TB 8TB 16TB 16TB
Maximum file size (Ext4) -- -- 16TB 16TB
Maximum file system size (Ext4) -- -- 16TB 16TB
Maximum file size (GFS) 2TB 16TB/8EB 16TB/8EB[7] N/A
Maximum file system size (GFS) 2TB 16TB/8EB 16TB/8EB[7] N/A
Maximum file size (GFS2) -- -- 25TB 100TB
Maximum file system size (GFS2) -- -- 25TB 100TB
Maximum file size (XFS) -- -- 100TB 100TB
Maximum file system size (XFS) -- -- 100TB 100TB
Maximum Boot LUN size (BIOS) -- -- <2TB <2TB[10]
Maximum Boot LUN size (UEFI) -- -- N/A Any[10]
Maximum x86 per-process virtual address space Approx. 4GB Approx. 4GB Approx. 3GB[4] Approx. 3GB[4]
Maximum x86_64 per-process virtual address space   512GB 2TB 128TB
Kernel and OS features        
Kernel foundation Linux 2.4.21 Linux 2.6.9 Linux 2.6.18 2.6.32 - 2.6.34
Compiler/toolchain GCC 3.2 GCC 3.4 GCC 4.1 GCC 4.4
Languages supported 10 15 19 22
NIAP/CC certified[11] Yes (3+) Yes (4+) Yes (4+) Under evaluation
Common Criteria certified KVM[11] -- -- Under evaluation Under evaluation
IPv6 -- -- Ready Logo Phase 2 Under evaluation
Compatibility libraries V2.1 V2.1 and V3 V3 and V4 V4 and V5
FIPS certified[11] -- -- Yes Under evaluation
Common Operating Environment (COE) compliant Yes Yes N/A N/A
LSB-compliant Yes - 1.3 Yes - 3 Yes - 3.1 Under evaluation
GB18030 No Yes Yes Yes
Client environment        
Desktop GUI Gnome 2.2 Gnome 2.8 Gnome 2.16 Gnome 2.28
Graphics XFree86 X.org X.org 7.1.1 X.org 7.4
OpenOffice V1.1 V1.1.2 V2.0.4[12] V3.2[12]
Gnome Evolution V1.4 V2.0 V2.8.0 V2.28
Default browser Mozilla Firefox Firefox 1.5[12] Firefox 3.6[12]

Notes:

  1. Supported limits reflect the current state of system testing by Red Hat and its partners for mainstream hardware. Systems exceeding these supported limits may be included in the Hardware Catalog after joint testing between Red Hat and its partners. If they exceed the supported limits posted here, entries in the Hardware Catalog will include a reference to the details of the system-specific limits and are fully supported. In addition to supported limits reflecting hardware capability, there may be additional limits under the Red Hat Enterprise Linux subscription terms. Supported limits are subject to change as ongoing testing completes.
  2. Red Hat defines a logical CPU as any schedulable entity. So every core/thread in a multicore/thread processor is a logical CPU.
  3. The "SMP" kernel supports a maximum of 16GB of main memory. Systems with more than 16GB of main memory use the "Hugemem" kernel. In certain workload scenarios it may be advantageous to use the "Hugemem" kernel on systems with more than 12GB of main memory.
  4. The x86 "Hugemem" kernel is not provided in Red Hat Enterprise Linux 5 or 6.
  5. The architectural limits are based on the capabilities of the RHEL kernel and the physical hardware. RHEL 6 limit is based on 46-bit physical memory addressing. RHEL 5 limit is based on 40-bit physical memory addressing. All system memory should be balanced across NUMA nodes in a NUMA-capable system.
  6. Red Hat Enterprise Linux 6 does not include support for the Itanium 2 architecture.
  7. If there are any 32-bit machines in the cluster, the maximum gfs file system size is 16TB. If all machines in the cluster are 64-bit, the maximum size is 8EB.
  8. Officially support 125 CPUs across the entire machine.
  9. Requires Intel EPT and AMD RVI technology support.
  10. UEFI and GPT support required for more that 2TB boot LUN support (https://access.redhat.com/kb/docs/DOC-16981).
  11. Get security certification details.
  12. Firefox, Thunderbird, and OpenOffice applications will be updated during the lifecycle.