HP c-Class Performance Tuning manual Contents

Contents
Introduction	5
About the Performance and Tuning Guide	5
System performance	6
Verifying Linux system performance	6
Running fio tests	6
Write bandwidth test	7
Verifying Windows system performance with Iometer	9
Debugging performance issues	10
Improperly configured benchmark	10
Oversubscribed bus	10
Handling PCIe errors	11
PCIe link width improperly negotiated	12
CPU thermal throttling or auto-idling	13
Benchmarking through a filesystem	14
Slow performance using RAID5 on Linux	14
Using CP and other system utilities	14
ext4 in Kernel.org 2.6.33 or earlier might silently corrupt data when discard (trim) is enabled	14
General tuning techniques	16
Using direct I/O, unbuffered, or zero copy 10	16
Multiple outstanding IOs	16
Pre-conditioning	17
Increasing outstanding requests allowed by the kernel (Linux only)	18
Pre-allocating memory	18
preallocate_memory	18
preallocate_mb	19
expected_io_size	19
Tuning techniques for writes	20
Increased steady-state write performance with fio-format	20
Linux filesystem tuning	21
ext2-3-4 tuning	21
Setting stride size and stripe width for ext2/3 (extN) when using RAID	21
Using the IO Accelerator as swap space	22
fio benchmark	23
Compiling the fio benchmark	23
Verifying IO Accelerator performance on Windows operating systems	24
Using Iometer to verify IO Accelerator performance on Windows operating systems	24
Programming using direct I/O	25
Using direct I/O on Linux	25
Using direct I/O on Windows	26
C++ code sample	26
Windows driver affinity	29
Contents	3