I analysed disk performance with blktrace and get some data:
read:
Code:
8,3 4 2141 2.882115217 3342 Q R 195732187 + 32 [cat]
8,3 4 2142 2.882116411 3342 G R 195732187 + 32 [cat]
8,3 4 2144 2.882117647 3342 I R 195732187 + 32 [cat]
8,3 4 2145 2.882118965 3342 D R 195732187 + 32 [cat]
8,3 4 2149 2.884145702 0 C R 195732187 + 32 [0]
write:
Code:
8,3 4 43622 5.305507398 3436 Q W 17805895 + 8 [bash]
8,3 4 43623 5.305508277 3436 G W 17805895 + 8 [bash]
8,3 4 43624 5.305508574 3436 I W 17805895 + 8 [bash]
8,3 2 414 5.306695591 0 D W 17805895 + 16 [swapper]
8,3 2 418 5.307020642 0 C W 17805895 + 16 [0]
And, d2c time of one read request is 0.002026737s. On the other hand, d2c time of one write request is 0.000325051s. It show: read time > write time. Is it right? why? I have no idea.
Hi,
Is mv (move) command quicker than cp (copy command)?
I have large files and I want to know if mv actually copy the data to a new file then deletes the old or whether it just alters information the file system without physically moving data - Unfortuanately I don't have large files to test... (2 Replies)
Hello,
I have a Supermicro server with a P4SCI mother board running Debian Sarge 3.1. This is the "dmidecode" output related to RAM info:
RAM speed information is incomplete.. "Current Speed: Unknown", is there anyway/soft to get the speed of installed RAM modules? thanks!!
Regards :)... (0 Replies)
If a file size increases in Linux/UNIX to say in GB's then will there be a decrease in write speed.
I mean will it take more time to write to a large file then to a small one??
Please clarify?
Thanks in advance (2 Replies)
hi
i'm greping the files with sepefic keyword, where the file is of too big. Assume there are 10 days log file each of more than 200mb. i've to grep all those files with a specific keywords.
for example,
1. i'll grep for error message
2. after the i'll do one more grep for keyword... (4 Replies)
Being a novice user to linux i m little unaware of how would i check disk read write speed.
One of my mate is suggesting to create a file using dd command and check how much time it takes to create a 30 gb file .
I think this has a little sense however i would also like to take your reviews... (5 Replies)
I am now on Kernel 2.6.32-26
For me 16x CD write speed is okay.
I have old hardware which was able to write DVDs at 1x, back in previous linux version.
Now, I dont get speed of less than 4x.
Tested on k3b, xfburn, and brasero. But all start at bottom 4x write speed. k3b forced back to... (0 Replies)
Hi,
I have to grep string from 20 - 30 files each carries 200 - 300 MB size and append to the
file. How to speed the
grepping time.
cat catalina.out_2012_01_01 | grep "xxxxx" >> backup.txt
PLZ, Suggest me,
Regards,
Nanthagopal A (5 Replies)
Hi,
We have two servers in scenario (vmsoldot01 is Oracle VM with Linux and tldtppod15 is physical Linux server). One NAS share is mounted on both servers with similar permissions and access. But READ speed is too bad on virtual in comparison to physical server.
While trying to diagnose this, I... (2 Replies)
Hello All,
I am building a real time parser for a log file in my application.
The log file is continuously written at a very fast pace and gets rolled over every 10 minutes.
I have measured the speed and observed that around 1000 lines are written to it every second, each line about 30-40... (7 Replies)
Discussion started by: cool.aquarian
7 Replies
LEARN ABOUT REDHAT
cat
CAT(1) FSF CAT(1)NAME
cat - concatenate files and print on the standard output
SYNOPSIS
cat [OPTION] [FILE]...
DESCRIPTION
Concatenate FILE(s), or standard input, to standard output.
-A, --show-all
equivalent to -vET
-b, --number-nonblank
number nonblank output lines
-e equivalent to -vE
-E, --show-ends
display $ at end of each line
-n, --number
number all output lines
-s, --squeeze-blank
never more than one single blank line
-t equivalent to -vT
-T, --show-tabs
display TAB characters as ^I
-u (ignored)
-v, --show-nonprinting
use ^ and M- notation, except for LFD and TAB
--help display this help and exit
--version
output version information and exit
With no FILE, or when FILE is -, read standard input.
AUTHOR
Written by Torbjorn Granlund and Richard M. Stallman.
REPORTING BUGS
Report bugs to <bug-coreutils@gnu.org>.
COPYRIGHT
Copyright (C) 2002 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICU-
LAR PURPOSE.
SEE ALSO
The full documentation for cat is maintained as a Texinfo manual. If the info and cat programs are properly installed at your site, the
command
info cat
should give you access to the complete manual.
cat (coreutils) 4.5.3 February 2003 CAT(1)