Speeding up SCP data transfers on the Sun SPARC T+ server line
I found the fowling Sun blog talking about SSH/SCP speed runing with the T1000/T2000 servers.
When using ssh or scp to transfer files to another server on the Niagara T1/2 boxes it will use only one virtual CPU which could be slow, as in the picture below
In contrast by using this script which also uses scp but copy’s in parllal the speed would increase drastically (depending on how many virtual CPU’s are used)
Note: that you might need to increase MaxStartups in server side sshd_config to 20 or higher. Alternatively, change conns=20 to conns=10 in pscp-test if you experience a problem, then restart sshd.
Before you use it, It is strongly suggest you to use this pscp test script that tests various download and upload transfers over localhost. You run it like this:
/tmp/pscp-test /var/tmp/user/pscp/ /tmp/pscp
The 1st parameter is a temporary directory with at least 0.5GB of free space, the 2nd argument is a full path to pscp script. You should see ALL TESTS PASSED as the last line of output and no obvious error output. If you don’t then do NOT use the pscp script and please report the problem to me.
Once all tests where successfully done, you could now run the pscp script like this
time /tmp/pscp -d -c 18 /var/tmp/user/sjsws-7_0-solaris-sparc.tar serverb:/tmp/ real 0m8.093s user 1m11.351s sys 0m17.169s vs time scp /var/tmp/user/sjsws-7_0-solaris-sparc.tar www18:/tmp/ real 0m38.269s user 0m33.654s sys 0m6.308s pscp help ---- pscp - parallel data transfer based on SSH Version 1.0 Usage: pscp user@host:file1 user@host:[dir | file2] Options: -b block size in bytes (default: 65536) -c number of parallel connections (default: 6) -d debug mode -h this help -q quiet mode; print only errors -s SHA1 verification of the transfered file (use for debug only) -t test mode; no reads, no writes, transfer only
The scp copy will now run in parllal as seen in the image below.