[LU-4193] increase maximum default ldiskfs journal size to 4GB

• Type: Improvement
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.6.0
• Assignee: Andreas Dilger
• Reporter: Andreas Dilger

Description

Testing has shown that a larger MDT journal size can increase performance significantly now that SMP scaling allows the MDT code to perform more operations per second. I'd like to increase the default journal size for newly formatted MDTs.

Performance test results shown with a 4GB journal size on the following hardware:

Intel(R) Xeon(R) CPU E5-2637 v2 @ 3.50GHz IVY BRIDGE
128 GB RAM
6x INTEL SSD S3700 400GB

1x Intel TrueScale Card QDR
2x Intel 82599EB 10-Gigabit SFI/SFP+
4x Intel I350 Gigabit

CentOS 6.4
Lustre 2.4.1 + CLIO simplification patch

Issue Links

• is related to: LU-4611 too many transaction credits (32279 > 25600)