[LU-12052] Performance improvmenets for single OSC

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Environment: master ; single OSS, single OST and single client
• Severity: 3
• Assignee: WC Triage
• Reporter: Shuichi Ihara

Description

Currently, single OST performance can achieve more than 10GB/sec easily. (e.g. 1 x RAID6(8D+2P) with 2GB/sec NVMe drive or 1 x DeclutteringRAID (100 x 200MB/sec NL-SAS drives). If there are N clients(N OST) against single OSS/OST, they can saturate maximum OST performance quickly. (e.g. 20 clients x 1GB/sec)
However, single OSC(single client) -> single OST performance doesn't scale very well today.

Here is an simple IOR(POSIX, 1MB, FPP) benchmark results from single client to single OSS/OST. The performance scales at beginning (PPN=1, PPN2..) but at the end, it hits limits.

NP　  single client(MB/s)  multiple client(PPN=1)
 1	   1,409	         1,409
 2	   2,573	         2,885
 4	   3,335	         5,887
 8	   3,520	        11,446
16	   3,676	        11,984