Sandia National Laboratories

TEST5
(Phase 1)

Description:
Each test performed is a single-shared-file test with an increasing number of clients. In each case a stripe width of 8 is used. The number of OST's used in each test is 8. The OST's are allocated in order on 4 OSS's. The same OSS nodes are used for each test.

Purpose:
The purpose of this test is to examine the file-system performance of share file access. This test is meant to illustrate test cases where the number of clients is both less than and greater than the number of OST's. The number of OST's used was intentionally limited to enable an oversubscription rate of approximately 60:1.

Performance

AVG PER OST Performance

 

AXES:
Y- MiB/sec aggregate transfer for each data point
X - <clients.stripe> increasing client count from 1-496, Constant stripe count of 8 (shared file).

Testing Parameters:
TEST CODE:    IOR
VERSION:    2.8.10
API:    POSIX
ACCESS:    single-shared-file
MAX OST's:    8
MAX OSS's:    4

Observations:
An initial ramp up is observed for both reads and writes. The ramp up of the read performance seems to max out at approximately 8 clients (equal to the number of OST's or stripe width). The ramp up of writes continues up to 24 clients (3 times oversubscription) without an easily notable deviation. The writes display what might be a saw tooth pattern observed in other tests beyond 24 clients. In general the writes appear to generally hold up. Based on the size of the error bar it is difficult to claim specifically what happens at the largest client size. The read performance again drops drastically after achieving the maximum rate.

Data in TABLE format

RAW data

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