两个命令：hdparm和iozone参数解释
1.hdpram：
haochuang@computer9:~$ hdparm -h
hdparm - get/set hard disk parameters - version v9.37, by Mark Lord.
Usage: hdparm [options] [device ...]
Options:
-a Get/set fs readahead
-A Get/set the drive look-ahead flag (0/1)
-b Get/set bus state (0 == off, 1 == on, 2 == tristate)
-B Set Advanced Power Management setting (1-255)
-c Get/set IDE 32-bit IO setting
-C Check drive power mode status
-d Get/set using_dma flag
-D Enable/disable drive defect management
-E Set cd/dvd drive speed
-f Flush buffer cache for device on exit
-F Flush drive write cache
-g Display drive geometry
-h Display terse usage information
-H Read temperature from drive (Hitachi only)
-i Display drive identification
-I Detailed/current information directly from drive
-k Get/set keep_settings_over_reset flag (0/1)
-K Set drive keep_features_over_reset flag (0/1)
-L Set drive doorlock (0/1) (removable harddisks only)
-m Get/set multiple sector count
-M Get/set acoustic management (0-254, 128: quiet, 254: fast)
-n Get/set ignore-write-errors flag (0/1)
-N Get/set max visible number of sectors (HPA) (VERY DANGEROUS)
-p Set PIO mode on IDE interface chipset (0,1,2,3,4,...)
-P Set drive prefetch count
-q Change next setting quietly
-Q Get/set DMA queue_depth (if supported)
-r Get/set device readonly flag (DANGEROUS to set)
-R Obsolete
-s Set power-up in standby flag (0/1) (DANGEROUS)
-S Set standby (spindown) timeout
-t Perform device read timings
-T Perform cache read timings
-u Get/set unmaskirq flag (0/1)
-U Obsolete
-v Use defaults; same as -acdgkmur for IDE drives
-V Display program version and exit immediately
-w Perform device reset (DANGEROUS)
-W Get/set drive write-caching flag (0/1)
-x Obsolete
-X Set IDE xfer mode (DANGEROUS)
-y Put drive in standby mode
-Y Put drive to sleep
-z Re-read partition table
-Z Disable Seagate auto-powersaving mode
--dco-freeze Freeze/lock current device configuration until next power cycle
--dco-identify Read/dump device configuration identify data
--dco-restore Reset device configuration back to factory defaults
--direct Use O_DIRECT to bypass page cache for timings
--drq-hsm-error Crash system with a "stuck DRQ" error (VERY DANGEROUS)
--fallocate Create a file without writing data to disk
--fibmap Show device extents (and fragmentation) for a file
--fwdownload Download firmware file to drive (EXTREMELY DANGEROUS)
--fwdownload-mode3 Download firmware using min-size segments (EXTREMELY DANGEROUS)
--fwdownload-mode3-max Download firmware using max-size segments (EXTREMELY DANGEROUS)
--fwdownload-mode7 Download firmware using a single segment (EXTREMELY DANGEROUS)
--idle-immediate Idle drive immediately
--idle-unload Idle immediately and unload heads
--Istdin Read identify data from stdin as ASCII hex
--Istdout Write identify data to stdout as ASCII hex
--make-bad-sector Deliberately corrupt a sector directly on the media (VERY DANGEROUS)
--offset use with -t, to begin timings at given offset (in GiB) from start of drive
--prefer-ata12 Use 12-byte (instead of 16-byte) SAT commands when possible
--read-sector Read and dump (in hex) a sector directly from the media
--security-help Display help for ATA security commands
--trim-sector-ranges Tell SSD firmware to discard unneeded data sectors: lba:count ..
--trim-sector-ranges-stdin Same as above, but reads lba:count pairs from stdin
--verbose Display extra diagnostics from some commands
--write-sector Repair/overwrite a (possibly bad) sector directly on the media (VERY DANGEROUS)
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语 法：hdparm [-CfghiIqtTvyYZ][-a <快取分区>][-A <0或1>][-c <I/O模式>][-d <0或1>][-k <0或1>][-K <0或1>][-m <分区数>][-n <0或1>][-p <PIO模式>][-P <分区数>][-r <0或1>][-S <时间>][-u <0或1>][-W <0或1>][-X <传输模式>][设备]
补充说明：hdparm可检测，显示与设定IDE或SCSI硬盘的参数。
参 数：
-a<快取分区> 设定读取文件时，预先存入块区的分区数，若不加上<快取分区>选项，则显示目前的设定。
-A<0或1> 启动或关闭读取文件时的快取功能。
-c<I/O模式> 设定IDE32位I/O模式。
-C 检测IDE硬盘的电源管理模式。
-d<0或1> 设定磁盘的DMA模式。
-f 将内存缓冲区的数据写入硬盘，并清楚缓冲区。
-g 显示硬盘的磁轨，磁头，磁区等参数。
-h 显示帮助。
-i 显示硬盘的硬件规格信息，这些信息是在开机时由硬盘本身所提供。
-I 直接读取硬盘所提供的硬件规格信息。
-k<0或1> 重设硬盘时，保留-dmu参数的设定。
-K<0或1> 重设硬盘时，保留-APSWXZ参数的设定。
-m<磁区数> 设定硬盘多重分区存取的分区数。
-n<0或1> 忽略硬盘写入时所发生的错误。
-p<PIO模式> 设定硬盘的PIO模式。
-P<磁区数> 设定硬盘内部快取的分区数。
-q 在执行后续的参数时，不在屏幕上显示任何信息。
-r<0或1> 设定硬盘的读写模式。
-S<时间> 设定硬盘进入省电模式前的等待时间。
-t 评估硬盘的读取效率。
-T 评估硬盘快取的读取效率。
-u<0或1> 在硬盘存取时，允许其他中断要求同时执行。
-v 显示硬盘的相关设定。
-W<0或1> 设定硬盘的写入快取。
-X<传输模式> 设定硬盘的传输模式。
-y 使IDE硬盘进入省电模式。
-Y 使IDE硬盘进入睡眠模式。
-Z 关闭某些Seagate硬盘的自动省电功能。
测试硬盘的读取速度：
普通磁盘测试：
# hdparm -t /dev/sda
/dev/sda:
Timing buffered disk reads: 316 MB in 3.02 seconds = 104.71 MB/sec
# hdparm -T /dev/sda
/dev/sda:
Timing cached reads: 19328 MB in 1.99 seconds = 9691.24 MB/sec
RAID0测试(两块盘)：
# hdparm -t /dev/sdb
/dev/sdb:
Timing buffered disk reads: 622 MB in 3.01 seconds = 206.89 MB/sec
# hdparm -T /dev/sdb1
/dev/sdb1:
Timing cached reads: 19632 MB in 1.99 seconds = 9844.20 MB/sec
RAID0测试(三块盘)：
# hdparm -t /dev/sdb
/dev/sdb:
Timing buffered disk reads: 846 MB in 3.00 seconds = 281.54 MB/sec
# hdparm -T /dev/sdb
/dev/sdb:
Timing cached reads: 18412 MB in 1.99 seconds = 9229.67 MB/sec
RAID0测试(四块盘)
/dev/sdb:
Timing cached reads: 19608 MB in 1.99 seconds = 9832.76 MB/sec
Timing buffered disk reads: 860 MB in 3.00 seconds = 286.35 MB/sec
另外ARID卡测试速度后，每次会警告：
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device
参考测试速度方法：time cp -a data2 data2
原文：http://blog.sina.com.cn/s/blog_60359c5b0100gjvw.html
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2.iozone：
haochuang@computer9:~$ iozone -h
iozone: help mode
Usage: iozone [-s filesize_Kb] [-r record_size_Kb] [-f [path]filename] [-h]
[-i test] [-E] [-p] [-a] [-A] [-z] [-Z] [-m] [-M] [-t children]
[-l min_number_procs] [-u max_number_procs] [-v] [-R] [-x] [-o]
[-d microseconds] [-F path1 path2...] [-V pattern] [-j stride]
[-T] [-C] [-B] [-D] [-G] [-I] [-H depth] [-k depth] [-U mount_point]
[-S cache_size] [-O] [-L cacheline_size] [-K] [-g maxfilesize_Kb]
[-n minfilesize_Kb] [-N] [-Q] [-P start_cpu] [-e] [-c] [-b Excel.xls]
[-J milliseconds] [-X write_telemetry_filename] [-w] [-W]
[-Y read_telemetry_filename] [-y minrecsize_Kb] [-q maxrecsize_Kb]
[-+u] [-+m cluster_filename] [-+d] [-+x multiplier] [-+p # ]
[-+r] [-+t] [-+X] [-+Z] [-+w percent dedupable] [-+y percent_interior_dedup]
[-+C percent_dedup_within]
-a Auto mode
-A Auto2 mode
-b Filename Create Excel worksheet file
-B Use mmap() files
-c Include close in the timing calculations
-C Show bytes transferred by each child in throughput testing
-d # Microsecond delay out of barrier
-D Use msync(MS_ASYNC) on mmap files
-e Include flush (fsync,fflush) in the timing calculations
-E Run extension tests
-f filename to use
-F filenames for each process/thread in throughput test
-g # Set maximum file size (in Kbytes) for auto mode (or #m or #g)
-G Use msync(MS_SYNC) on mmap files
-h help
-H # Use POSIX async I/O with # async operations
-i # Test to run (0=write/rewrite, 1=read/re-read, 2=random-read/write
3=Read-backwards, 4=Re-write-record, 5=stride-read, 6=fwrite/re-fwrite
7=fread/Re-fread, 8=random_mix, 9=pwrite/Re-pwrite, 10=pread/Re-pread
11=pwritev/Re-pwritev, 12=preadv/Re-preadv)
-I Use VxFS VX_DIRECT, O_DIRECT,or O_DIRECTIO for all file operations
-j # Set stride of file accesses to (# * record size)
-J # milliseconds of compute cycle before each I/O operation
-k # Use POSIX async I/O (no bcopy) with # async operations
-K Create jitter in the access pattern for readers
-l # Lower limit on number of processes to run
-L # Set processor cache line size to value (in bytes)
-m Use multiple buffers
-M Report uname -a output
-n # Set minimum file size (in Kbytes) for auto mode (or #m or #g)
-N Report results in microseconds per operation
-o Writes are synch (O_SYNC)
-O Give results in ops/sec.
-p Purge on
-P # Bind processes/threads to processors, starting with this cpu
-q # Set maximum record size (in Kbytes) for auto mode (or #m or #g)
-Q Create offset/latency files
-r # record size in Kb
or -r #k .. size in Kb
or -r #m .. size in Mb
or -r #g .. size in Gb
-R Generate Excel report
-s # file size in Kb
or -s #k .. size in Kb
or -s #m .. size in Mb
or -s #g .. size in Gb
-S # Set processor cache size to value (in Kbytes)
-t # Number of threads or processes to use in throughput test
-T Use POSIX pthreads for throughput tests
-u # Upper limit on number of processes to run
-U Mount point to remount between tests
-v version information
-V # Verify data pattern write/read
-w Do not unlink temporary file
-W Lock file when reading or writing
-x Turn off stone-walling
-X filename Write telemetry file. Contains lines with (offset reclen compute_time) in ascii
-y # Set minimum record size (in Kbytes) for auto mode (or #m or #g)
-Y filename Read telemetry file. Contains lines with (offset reclen compute_time) in ascii
-z Used in conjunction with -a to test all possible record sizes
-Z Enable mixing of mmap I/O and file I/O
-+E Use existing non-Iozone file for read-only testing
-+K Sony special. Manual control of test 8.
-+m Cluster_filename Enable Cluster testing
-+d File I/O diagnostic mode. (To troubleshoot a broken file I/O subsystem)
-+u Enable CPU utilization output (Experimental)
-+x # Multiplier to use for incrementing file and record sizes
-+p # Percentage of mix to be reads
-+r Enable O_RSYNC|O_SYNC for all testing.
-+t Enable network performance test. Requires -+m
-+n No retests selected.
-+k Use constant aggregate data set size.
-+q Delay in seconds between tests.
-+l Enable record locking mode.
-+L Enable record locking mode, with shared file.
-+B Sequential mixed workload.
-+D Enable O_DSYNC mode.
-+A # Enable madvise. 0 = normal, 1=random, 2=sequential
3=dontneed, 4=willneed
-+N Do not truncate existing files on sequential writes.
-+S # Dedup-able data is limited to sharing within each numerically
identified file set
-+V Enable shared file. No locking.
-+X Enable short circuit mode for filesystem testing ONLY
ALL Results are NOT valid in this mode.
-+Z Enable old data set compatibility mode. WARNING.. Published
hacks may invalidate these results and generate bogus, high
values for results.
-+w ## Percent of dedup-able data in buffers.
-+y ## Percent of dedup-able within & across files in buffers.
-+C ## Percent of dedup-able within & not across files in buffers.
-+H Hostname Hostname of the PIT server.
-+P Service Service of the PIT server.
-+z Enable latency histogram logging.