Белая книга для Cisco Cisco UCS C22 M3 Rack Server
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White Paper
Cisco UCS C240 M4 I/O Characterization
Executive Summary
This document outlines the I/O performance characteristics of the Cisco UCS
®
C240 M4 Rack Server using the
Cisco
®
12-Gbps SAS modular RAID controller (UCSC-MRAID12G). Performance comparisons of various serial-
attached Small Computer System Interface (SCSI; SAS) hard-disk drives (HDDs), solid-state drives (SSDs),
Redundant Array of Independent Disk (RAID) configurations, and controller options are presented. This white
paper aims to assist customers in making well-informed decisions in choosing the right internal disk types and
configuring the right controller options and RAID levels to meet their individual I/O workload needs.
Performance data was obtained using the Iometer measurement tool, with analysis based on the metrics of
input/output operations per second (IOPS) for random I/O workloads, and megabytes per second (MBps)
throughput for sequential I/O workloads. From this analysis, specific recommendations are made for storage
configuration parameters.
Many combinations of different drive types and RAID levels are possible. For these characterization tests,
performance evaluations were limited to 7200-rpm small form factor (SFF) HDDs, 10,000-rpm SFF HDDs, and SFF
SSD drive types, with configurations of RAID 0, RAID 5, and RAID 10 virtual disks.
Tables 1 and 2 list the recommended virtual drive configuration parameters for deployment of SSDs and HDDs.
Table 1.
Recommended Virtual Drive Configuration Parameters for Solid-State Drives
Workload
RAID Level
Strip Size
Disk Cache Policy
I/O Cache Policy
Read Policy
Write Policy
Random I/O
RAID 0
256 KB
Disabled
Direct
Normal Read
Write Through
Random I/O
RAID 10
256 KB
Disabled
Direct
Normal Read
Write Through
Random I/O
RAID 5
256 KB
Disabled
Direct
Normal Read
Write Through
Sequential I/O
RAID 0
256 KB
Disabled
Direct
Normal Read
Write Through
Sequential I/O
RAID 10
256 KB
Disabled
Direct
Normal Read
Write Through
Sequential I/O
RAID 5
256 KB
Disabled
Direct
Normal Read
Write Through
Table 2.
Recommended Virtual Drive Configuration Parameters for Hard-Disk Drives
Workload
RAID Level
Strip Size
Disk Cache Policy
I/O Cache Policy
Read Policy
Write Policy
Random I/O
RAID 0
256 KB
Disabled
Cached
Read Ahead
Write Back w/BBU
Random I/O
RAID 10
256 KB
Disabled
Cached
Read Ahead
Write Back w/BBU
Random I/O
RAID 5
256 KB
Disabled
Cached
Read Ahead
Write Back w/BBU
Sequential I/O
RAID 0
256 KB
Disabled
Cached
Read Ahead
Write Back w/BBU
Sequential I/O
RAID 10
256 KB
Disabled
Cached
Read Ahead
Write Back w/BBU
Sequential I/O
RAID 5
256 KB
Disabled
Cached
Read Ahead
Write Back w/BBU