Here's a copy of the disk manual from Seagate:
http://www.seagate.com/support/disc/manuals/scsi/100148123b.pdf
The internal disk rate varies from 632-891 Mbits/sec. That's approximately 60-80 MBytes/sec inside the disk. While the internal 8 MByte cache may be able to push data faster, after 8 MBytes, the rotational speed and internal controller overhead will not allow continuous transfers faster than about 50 MBytes/sec. I've measured serial read speeds for internal disks from K370's, n4000's, rp8420's and rp3440's (raw disk, no interlace) using dd and none of the internal disks get much above 70 MBytes/sec, averaging about 35-50 MBytes/sec.
Here's the code for my diskperf script. It's just a wrapper around dd with some math to make the results easier to read. It is pasted here due to attached file restrictions in the Community forums. Here is the usage:
Requires MB (or all) and at least one DSF
=========================================
Usage: diskperf [-l log] [-a] [-r <KB>] <MB> <DSF/lvol> [<DSF/lvol>... ]
where: -l log file
-a = always append to log, otherwise new log started
-r <KB> where <KB> is a 1024 block
(min=1 KB, default=1024 KB, max=16384 KB)
-v verbose messages
and: MB = megabytes to read (MB = 1024*1024) or "all"
The keyword "all" reads the entire disk/LUN
DSF = fullpath to LUN device file or any directory
Will run a dd read test on the raw device or directory (lvol)
and report performance. Optionally write the results to a logfile.It is useful to see the effects of interlacing either at the LVM lavel or through a Smart Array.
#!/usr/bin/sh
#######################
# #
# D I S K P E R F #
# #
#######################
# Simple dd tests of a raw disk device or lvol
# Date By What
########### ##### #########################################################
# 2015.0804 blh Fixed error when bdf line is split
# 2015.0504 blh Warn that diskperf doesn't run in an SRP container
# 2015.0424 blh Remove time from the dd line (errmo and stderr lost)
# Report using $SECONDS and stderr
# 2014.0711 blh Added directory as input
# 2014.0422 blh Added ability to specify alternate disk types as iSCSI or
# VG components such as lvols. Script will verify raw.
# Basename only has been dropped - requires fullpath
# Moved timestamp on results to VERBOSE only
# Added -a to always append to the log
# 2013.0628 blh Added all keyword for a full dd of the disk
# Added -v for details
# 2011.0527 blh Added recsize option
# 2008.0821 blh Original version
set -u
export PATH=/usr/bin:/usr/sbin
MYNAME=${0##*/}
MYID=$(id -un)
tty -s # Check if interactive
[[ $? -eq 0 ]] &&
export MYTTY=true ||
export MYTTY=false
TRACEME=${TRACEME:-false} # TRACEME non-null = trace on
[[ $TRACEME != false ]] && set -x && PS4='[$LINENO]: '
RECSZKB=1024 # default records size in KB (ie, 1024 KB or 1 MB)
MAXRECSZKB=16384 # larger may exceed HP-UX buffers (rev dependent)
###############################################################
USAGETXT="
Usage: $MYNAME [-l log] [-a] [-r <KB>] <MB> <DSF/lvol> [<DSF/lvol>... ]
where: -l log file
-a = always append to log, otherwise new log started
-r <KB> where <KB> is a 1024 block
(min=1 KB, default=$RECSZKB KB, max=$MAXRECSZKB KB)
-v verbose messages
and: MB = megabytes to read (MB = 1024*1024) or \"all\"
The keyword \"all\" reads the entire disk/LUN
DSF = fullpath to LUN device file or any directory
Will run a dd read test on the raw device or directory (lvol)
and report performance. Optionally write the results to a logfile.
"
###############################################################
#########################
# F U N C T I O N S #
#########################
###########
# Usage #
###########
function Usage
{
# Minimum Usage function
# Requires $USAGETXT to be assigned externally.
# Typically, this is done at the start of a script
# to act as both documentation and a Usage message
TRACEME=${TRACEME:-false} # TRACEME non-null = trace on
[ $TRACEME != false ] && set -x && PS4='[$LINENO]: '
MYNAME=${MYNAME:-${0##*/}}
# If supplied, show an error message
if [ $# -gt 0 ]
then
ERRMSG="$*"
echo "\n$ERRMSG"
WIDTH=${#ERRMSG}
eval typeset -Z$WIDTH BAR=0
echo "$BAR" | tr "0" "="
fi
# Show the usage message - handle missing USAGETXT
USAGETXT=${USAGETXT:-NotSet}
[[ "$USAGETXT" = "NotSet" || "$USAGETXT" = "" ]] &&
echo "\n$MYNAME: USAGETXT is null or not assigned" ||
echo "$USAGETXT"
exit 1
}
##############
# Indent #
##############
function Indent
{
TRACEME=${TRACEME:-false} # TRACEME non-null = trace on
[[ $TRACEME != false ]] && set -x && PS4='[$LINENO]: '
# Indent multiple text lines
# Usage:
# Indent "text" [ indent-num ]
# or
# cat something | Indent "" [ indent-num ]
#
# Maintains leading spaces by changing IFS temporarily
# No text? Just return
[[ "$1" = "" ]] && return
# If no indent-num, use 4 as a default
[ $# -gt 1 ] && INDENT=$2 || INDENT=4
# $1 is the string to indent. Don't use $@ as $1
# could be multiple lines in 1 string
#
# But if "$1" = "" (null), then read from STDIN and use
# "" (null string) as a placeholder when using the
# optional indent value:
#
# vgdisplay -v | Indent "" 6
if [[ $# -eq 0 ]]
then
READTEXT="cat" # stdin with no indent amount
else
[[ "$1" = "" ]] && # stdin with null text and indent amount
READTEXT="cat" ||
READTEXT="echo \"$1\"" # indent the $1 text
fi
# To preserve leading white space with a read, change IFS to the null string,
# then change back # because it is exported from the parent env.
OLDIFS="$IFS"
IFS=""
eval "$READTEXT" | while read TEXT
do
eval "typeset -R$INDENT SPACES=' '"
echo "$SPACES$TEXT"
done
# Always put back the original IFS
IFS="$OLDIFS"
return
}
#################
# MakeBDFLIST #
#################
function MakeBDFLIST
{
## run bdf with a specific directory location, or nothing for a complete list
## The exported variable BDFLIST contains the result
TRACEME=${TRACEME:-false} # TRACEME non-null = trace on
[[ $TRACEME != false ]] && set -x && PS4='[$LINENO]: '
[[ $# -eq 0 ]] && MNTPNT="" || MNTPNT="$1"
export BDFLIST="$(bdf -l "$MNTPNT" 2>/dev/null | while read FS TOT USED AVAIL PERCENT MNT
do
if [ $FS != "Filesystem" ] # skip header
then
if [ "$TOT" = "" ] # check for split lines
then
read TOT USED AVAIL PERCENT MNT
fi
echo $FS $TOT $USED $AVAIL $PERCENT $MNT # single line result
fi
done)"
return
}
########################################################################
# M A I N P R O G R A M
########################################################################
## bailout if inside an SRP container
if [[ -r /opt/hpsrp/bin/srp_env ]]
then
SRPTEXT="$(/opt/hpsrp/bin/srp_env 2>&1)"
RTN=$?
if [[ $RTN -eq 0 ]]
then
if [[ $(echo "$SRPTEXT" | grep -c -i "enabled") -eq 0 ]]
then
if [[ "$(echo "$SRPTEXT" | awk '/^type:/{print $NF}')" != global ]]
then
echo "\n($MYNAME not supported inside an SRP container)\n"
exit 1
fi
fi
fi
fi
[[ $# -eq 0 ]] &&
CMDLINE="$(whence $0)" ||
CMDLINE="$(whence $0) $@"
RESULTSLOG="/dev/null" # This way, everything is sent to the log
APPEND=false # start new log
VERBOSE=false
# Look for optional logfile and recsize
########################################
while getopts ":al:r:v" OPTCHR
do
case $OPTCHR in
a) APPEND=true
;;
l) RESULTSLOG="$OPTARG"
;;
r) RECSZKB="$OPTARG"
;;
v) VERBOSE=true
;;
*) eval "ERROPT=\$$(($OPTIND-1))"
Usage "Invalid option: $ERROPT"
;;
esac
done
shift $(($OPTIND -1))
# Validity checks
#####################################
[[ $# -lt 2 ]] &&
Usage "Requires MB (or all) and at least one DSF"
MEGS=$1
if [[ "$MEGS" != "all" && "$MEGS" != "ALL" ]]
then
[[ $(print -n $MEGS | tr -d '[:digit:]' | wc -c) -gt 0 ]] &&
Usage "MB ($MEGS) is not a number"
[[ $MEGS -lt 5 ]] &&
Usage "MB must be 5 or larger"
else
MEGS=ALL
fi
# Validate record size option
[[ $(print -n $RECSZKB | tr -d '[:digit:]' | wc -c) -gt 0 ]] &&
Usage "KB recsize is not a number"
[[ $RECSZKB -lt 1 || $RECSZKB -gt 16384 ]] &&
Usage "Invalid record size ($RECSZKB)"
shift 1
## Logfile setup
touch $RESULTSLOG
RTN=$?
[[ $RTN -ne 0 ]] && Usage "$RESULTSLOG logfile not writable by $MYID"
[[ $APPEND = false ]] && cat /dev/null > $RESULTSLOG
echo "==================================================" >> $RESULTSLOG
[[ $VERBOSE = true ]] &&
TEEORNOT=" | tee -a $RESULTSLOG" ||
TEEORNOT=" >> $RESULTSLOG"
eval echo "$(date)" $TEEORNOT
# Always show command line when logging, and only stdout when VERBOSE
eval echo "CMD: $CMDLINE" $TEEORNOT
## Loop through each device
## Fullpath LUN names are normalized to the raw device
## Directories are translated to the rlvol name
## NFS/CDFS locations are rejected
## Make a bdf list of 1-liners
for SOURCEDEV in $@
do
case $SOURCEDEV in
/dev/d*sk/*) ## block devicefile
DSKDEV=$(echo $SOURCEDEV | awk -F/ '{print "/dev/r"$3"/"$4}')
;;
/dev/rd*sk/*) ## raw devicefile
DSKDEV=$SOURCEDEV
;;
*) if [[ -d $SOURCEDEV ]] ## must be a directory
then
# Handle split line bdf
MakeBDFLIST $SOURCEDEV
SOURCE="$(echo $BDFLIST | awk '{print $1}')"
RTN=$?
if [[ $RTN -ne 0 ]]
then
echo "\n$SOURCEDEV is not a disk device or directory name\n" | tee -a $RESULTSLOG
break
else
if [[ "$(bdf -l $SOURCEDEV 2>&1)" = "" ]]
then
echo "\n$SOURCEDEV is a network filesystem, cannot test.\n" | tee -a $RESULTSLOG
break
fi
DSKDEV=$(echo $SOURCE | awk -F/ '{print "/dev/"$3"/r"$4}')
fi
else
echo "$SOURCEDEV is not disk device or directory name\n" | tee -a $RESULTSLOG
break
fi
;;
esac
## The DSKDEV is a raw LUN or raw lvol now
## An lvol returns nothing from lssf if it exists
DISKTYPE=""
LSSF="$(lssf $DSKDEV 2>&1)"
if [[ "$LSSF" != "" ]]
then
# DSKDEV is a LUN
# Is the h/w connected?
if [[ $(echo "$LSSF" | grep -c '???') -ne 0 ]]
then
echo "$DSKDEV: is in NO_HW state" | tee -a $RESULTSLOG
continue
fi
# How big is this disk?
DISKSTAT=$(diskinfo $DSKDEV 2>&1)
RTN=$?
if [[ $RTN -ne 0 ]]
then
echo "$DSKDEV failed diskinfo\n$(Indent "$DISKSTAT")" | tee -a $RESULTSLOG
continue
fi
DISKTYPE="$(echo "$DISKSTAT" | awk '/type: /{print $NF}')"
DISKSIZEKB="$(echo "$DISKSTAT" | awk '/size:/{print $2}')"
[[ $VERBOSE = true ]] &&
echo "==> diskinfo $DSKDEV:\n$(Indent "$DISKSTAT")" | tee -a $RESULTSLOG
# logical volume - only LVM for now
# If non-standard names are used, the read-entire-disk option won't work
# DSKDEV is raw lvol here
else
DIRNAME=${DSKDEV%/*}
BASENAME=${DSKDEV##*/}
BLOCKNAME="$(echo "$BASENAME" | cut -c2-)"
if [[ ! -b $DIRNAME/$BLOCKNAME && $MEGS = all ]]
then
echo "For $DSKDEV, block device $DIRNAME/$BLOCKNAME not found\n\"all\" megs not available" |
tee -s $RESULTSLOG
break
else
[[ $MEGS = ALL ]] &&
MEGS=$(lvdisplay $DIRNAME/$BLOCKNAME | awk '/LV Size/{print $4}')
fi
fi
# run a short dd test to see if the device is readable
######################################################
dd if=$DSKDEV of=/dev/null bs=1024 count=1 >/dev/null 2>&1
RTN=$?
if [[ $RTN -ne 0 ]]
then
[[ "$DISKTYPE" = "" ]] && DT="" || DT=" (type=$DISKTYPE)"
echo "$DSKDEV:$DT not readable, skipping" | tee -a $RESULTSLOG
continue
fi
# Compute size of disk if MEGS=ALL and adjust record count
if [[ "$MEGS" = "ALL" ]]
then
RECCOUNT=$(($DISKSIZEKB/$RECSZKB))
[[ $VERBOSE = true ]] &&
echo "==> Read entire disk $DSKDEV" | tee -a $RESULTSLOG
else
RECCOUNT=$(($MEGS*1024/$RECSZKB))
fi
TOTALTOREAD=$(($RECCOUNT*$RECSZKB/1024))
[[ $VERBOSE = true ]] &&
echo "==> RecSZ=${RECSZKB}KB count=$RECCOUNT total=${TOTALTOREAD} MB" | tee -a $RESULTSLOG
# busy prompt
if [[ $MYTTY = true ]]
then
echo "...reading $DSKDEV, $MEGS MB...\r\c"
fi
## Run the full dd test
#######################
# SECS=$(time dd if=$DSKDEV of=/dev/null bs=${RECSZKB}k count=$RECCOUNT 2>&1 \
# | awk '/real/ {print $2}')
SECONDS=0
TXT="$(dd if=$DSKDEV of=/dev/null bs=${RECSZKB}k count=$RECCOUNT 2>&1)"
RTN=$?
SECS=$SECONDS
if [[ $RTN -ne 0 ]]
then
echo "\n$DSKDEV read error has occurred" | tee -a $RESULTSLOG
Indent "$TXT" | tee -a $RESULTSLOG
continue
fi
# Handle a very short elapsed time (0 secs) as a special case to avoid
# divide by zero
if [[ $SECS -eq 0 ]]
then
echo "$DSKDEV elapsed time = 0 secs, increase data size" | tee -a $RESULTSLOG
continue
fi
MBS=$(echo "scale=1;$RECSZKB*$RECCOUNT/1024/$SECS" | bc)
MYDATE=$(date '+%Y%m%d.%H%M%S')
# Show the results
##################
[[ $VERBOSE = true ]] &&
STATMSG="$MYDATE " ||
STATMSG=""
echo "${STATMSG}$DSKDEV: read ${MEGS} MB in $SECS secs ($RECCOUNT recs @ ${RECSZKB} KB) = ${MBS} MB/sec" |
tee -a $RESULTSLOG
doneTested on HP-UX 10.20 through 11.31.
Bill Hassell, sysadmin
