back up speed. 1

[nandkumar4aix]

Hi
i am using legato 5.5.1 on aix 4.3.2 as a server which is backing up some solaris boxes .

in this senario do i need diff licence for solaris client, i already hav 25 client licence for aix.

while taking back up of solaris boxes the back up speed is very low (around 100 - 200 kbps) . i am using storagetek timerwolf 9710 for backup (dlt 7000) .
but while taking back up of aix server its very fast(around 5-6 mbps) .

can anybody explain me why there is so much of speed diff. and what all factors affect the backup speed?

please give me some suggetions to improve my back up performence.
all suggetions , ideas are welcome.

thanks
nan aix sys admin
***************
nandkumarg@visto.com

 

[dangerman]

we've had a similar problem recently - backups appeared to be running OK for some machines (expecially the local server) but very slow for other machines (down to 20Kbps!)

It turned out to be that some network adapters were set to Half-duplex. While this didn't present a problem in every day server usage (i.e. the applications all ran OK and performance was fine) the backups failed to sustain sufficient network throughput. This occurred because our NICs were auto-sensing but this was not supported by our switches and caused the NICs to default to half-duplex. Changing this to full-duplex instantly fixed the problem. This may not be the cause of your problem but it's one thing to double-check ;-)

 

[mgdaviso]

forcing my NIC's to 100/Full solved exactly the same problem for me Mike davison
mike.davison@avon.com

 

[cfowler]

If you force your servers to 100/full, you will have to set the port that server connects through to 100/full also. For example, if the server = 100/full, then the port it connects to on the switch should = 100/full. Auto negotiate may function sometimes and not function other times.

Something to check.

Good luck,

cfowler

 

[icebox]

Exactly how do you configure your NICs to 100/full? Im pretty new at the networking stuff. Seems I know more about Legato than I do networking. Thanks for your help.

J

 

[cfowler]

Icebox,

Well... You really have to know your networking to use Legato. It's completely dependent upon your network configuration. You will most definitely wish to seek knowledge in the areas of DNS, TCP/IP and basic networking. At any rate, you can do the following:

1. right click on Network Neighborhood;
2. Select Properties;
3. Click on the Adapters Tab;
4. Highlight the Adapter listed and select Properties;
5. Look for Speed and Duplexing Entries;
6. Change the entries to 100 for speed and Full for Duplexing;

Keep in mind that if the port on the switch you are connecting to is set to another value, the above steps will only complicate matters. You must make certain that the port on the switch you are connecting to is the same as the NIC.

Good luck,

cfowler #-)

 

[icebox]

I guess I am not that new at the networking aspect of it all. I just don't consider myself a guru-network-god. I have worked with DNS and TCP/IP, just never configured TCP/IP or my NIC. I believe your instructions were with Windows. Do you know where I could find out this information for unix? Thanks a lot for your reply and information.

J
X-)

 

[daveketley]

The best we get is 5 or 6 mb/s backup speed with dlt7000 and 100mbit/s network - or 20GB an hour. Anything less than that is usually a duplex/speed mismatch. The legato server and client network cards must be hard set to 100MB full duplex along with the switch ports they're plugged into.

Dave