How to Check Disk Read Write Speed in Linux Server CentOS 6.4

1. Introduction
Hdparm is a free tool to measure sequential disk performance which is primarily used to tune and optimize disk parameters. It is important to read hdparm man page and perform full backup before using hdparm command line utility. The popular option for hdparm command line utility are -t and -T.
-t is to perform buffered disk read which is the data transfer rate directly from the disk to memory.
-T is to perform timing cached read which is the data transfer rate from a memory buffer without reading the hard drive.
2. Using hdparm
[root@howtolinux ~]# hdparm

hdparm - get/set hard disk parameters - version v9.16

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 acoustic management (0-254, 128: quiet, 254: fast)
 -m   get/set multiple sector count
 -N   get/set max visible number of sectors (HPA) (VERY DANGEROUS)
 -n   get/set ignore-write-errors flag (0/1)
 -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   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   disable Seagate auto-powersaving mode
 -z   re-read partition table
 --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)
 --fibmap          show device extents (and fragmentation) for a file
 --fibmap-sector   show absolute LBA of a specfic sector of 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)
 --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-sectors    tell SSD firmware to discard unneeded data sectors (lba and count)
 --verbose         display extra diagnostics from some commands
 --write-sector    repair/overwrite a (possibly bad) sector directly on the media (VERY DANGEROUS)
Note : Substitute /dev/sda with the name of the disk device.
Example on how to check disk Disk Read Write Speed for /dev/sda on CentOS6.4 :
[root@howtolinux ~]# hdparm -tT /dev/sda

/dev/sda:
 Timing cached reads:   528 MB in  2.00 seconds = 263.86 MB/sec
 Timing buffered disk reads:  122 MB in  3.06 seconds =  39.91 MB/sec