use hdparm change ATA SATA DISK's Write-Read-Verify feature set

前面测试了OCZ PCI-E接口的SSD硬盘RevoDrive3的性能, 确实不错.

其中hdparm看到的信息如下 : 

有一条, Write-Read-Verify feature set

也就是说这个硬盘支持这个特性, 只是没有开启.

但是hdparm系统带的版本不能修改这个. 需要用到更新的hdparm版本.

下载地址 : http://sourceforge.net/projects/hdparm/

编译时会有点问题, 我这用到的是CentOS 5.7 x64的版本.

hdparm.o: In function `dump_sectors':
hdparm.c:(.text+0x19c0): undefined reference to `le16toh'
hdparm.c:(.text+0x19ee): undefined reference to `le16toh'
hdparm.c:(.text+0x1a24): undefined reference to `le16toh'
collect2: ld returned 1 exit status
gmake: *** [hdparm] Error 1

原因是找不到这个函数, 这个函数原本应该在endian.h中声明的. 但是CentOS 5.7 x64的endian.h中没有. 

这个函数的功能参考 : 

http://www.kernel.org/doc/man-pages/online/pages/man3/endian.3.html

所以需要修改一下hdparm.c 以下行 :

printf("%04x", le16toh(w[0]));  

注释这行

// printf("%04x", le16toh(w[0]));  

或者修改这行.

printf("%04x", w[0]);  

再编译 :

gmake
gmake install

确认版本信息 :

[root@db-172-16-3-150 hdparm-9.43]# hdparm -V
hdparm v9.43

使用帮助 :

[root@db-172-16-3-150 hdparm-9.43]# hdparm -h

hdparm - get/set hard disk parameters - version v9.43, 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
 -J   Get/set Western DIgital "Idle3" timeout for a WDC "Green" drive (DANGEROUS)
 -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   Get/set device write-read-verify flag
 -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)

开启write-read-verify :

[root@db-172-16-3-150 hdparm-9.43]# hdparm -R 2 /dev/mapper/mpath1
/dev/mapper/mpath1:
 setting write-read-verify to 2
 write-read-verify =  2

确认已经开启 :

[root@db-172-16-3-150 hdparm-9.43]# hdparm -I /dev/mapper/mpath1|grep Write-Read-Verify
           *    Write-Read-Verify feature set

开启后IO性能将急剧下降.

关闭write-read-verify :

[root@db-172-16-3-150 hdparm-9.43]# hdparm -R 0 /dev/mapper/mpath1
/dev/mapper/mpath1:
 setting write-read-verify to 0
 write-read-verify =  0

确认已经关闭 : 

[root@db-172-16-3-150 hdparm-9.43]# hdparm -I /dev/mapper/mpath1|grep Write-Read-Verify
                Write-Read-Verify feature set

【参考】

1. http://sourceforge.net/projects/hdparm/

2. http://blog.163.com/digoal@126/blog/static/163877040201210279569426/

3. http://blog.163.com/digoal@126/blog/static/1638770402012102613815282/
4. http://www.kernel.org/doc/man-pages/online/pages/man3/endian.3.html