I have a linux server which has about 5 volumes from SAN (fiber channel) now I need to measure the transfer rate between one LUN which is a Logical Volume to another LUN which is another Logical Volume.
so basically this server has 5 LUNs from SAN
each SAN volume is a logical volume presented to linux
any tool to measure transfers rate (Megabytes per second)
so while I copy a file like 1 Terabyte I can get MB/second
Since this is Linux, if you send a SIGUSR1 to dd while it's in operation, it will print statistics to standard error.
It will also print a summary to standard error when it completes.
You may want to add "oflag=sync" to prevent cache effects from messing up your numbers.
These 2 Users Gave Thanks to Corona688 For This Post:
i have to take a closer look since I did not get the idea just reading it
Quote:
Originally Posted by Corona688
Since this is Linux, if you send a SIGUSR1 to dd while it's in operation, it will print statistics to standard error.
It will also print a summary to standard error when it completes.
You may want to add "oflag=sync" to prevent cache effects from messing up your numbers.
dd is a general purpose data moving command. It's sometimes used for moving data from one raw disk to another but it's a flexible command and doesn't care what kind of files or devices it's talking to.
dd by itself just reads stdin and writes back to stdout, so dd < filename > newfile is effectively the same thing as cp.
It does it in blocks of 512 bytes by default, which is a bit inefficient, so dd bs=1048576 < filename > newfile may be much faster. Beyond a certain point making the buffer bigger doesn't help.
So all I'm doing is having dd read from one file and write to another, and while it's running, sending it the signal SIGUSR1 which casues it to print statistics. Or you could wait for it to end, or kill it with ctrl-C, and it'll print statistics as it ends.
cache effects are when the OS doesn't immediately store what you've written to file on disk, just in memory. This is great for programs since they don't have to wait for the disk to catch up but troublesome for benchmarks. dd in linux supports the oflag=sync option to tell it not to do that.
I have D-Link Router DSL-2730U that support busybox OS and iptables version 1.4.0
I managed successfully to block the host for being connect to the internet using the following command
block by ip address
iptables -I FORWARD -d 192.168.1.6 -j DROP
Or By mac source
iptables -I... (0 Replies)
Hi,
I am experiencing extremely show transfer rates when transferring zip files over SFTP. Over FTP it works fine.
I have disabled compression in the sshd_config file but that does not seem to help..
Any ideas? (0 Replies)
I only have two disk in my HP machine
but when i execute iostat command
device bps sps msps
c0t0d1 0 0.0 1.0
disk0 49 2.8 1.0
disk5 0 0.0 1.0
I didn't know where device name disk0 and disk5
device name disk0 disk5 ,it is really disk
or... (3 Replies)