Slow multicast?

[falko]

Hi we have seperate Vlans here server, student and staff

student and staff dhcp options 66/67 has been configured on both of these vlans pxe menu/unicasting works great, 100mb network unicast speeds of 1.25gb/min

switches are cisco with multicasting enabled
when trying a multicast with the same 2 pc’s that were used for unicasting the multicast speed drops to 10mb/min any ideas or tests I can run?

server spec is
fog 0.32 ubuntu server 11.10
Linux 3.0.0-15-server on x86_64
Intel Core2 Duo CPU E6750 @ 2.66GHz, 2 cores
2gb ram

[falko]

(bump) anyone have any ideas/settings to check?
ghost multicast works and can image a suite in one hour, but fog says it will take 30+

[falko]

okay so I have believe I have fixed the issue after rebuilding the server a few times. I settled with ubuntu 10.04.03 in the end. During FOG install I set the mysql root password as normal

Using Webadmin, I logged into the mysql section created a new user (fogadmin) and password, giving this account full permission. I then edited the MYSQL info in /var/www/fog/commons/config.php + /opt/fog/service/etc/config.php. to match. Multicast speed is now at 670+ mb/min.

also I am now using the newly released kernel 3.2.4

this week I will move the server to a gigabit port on the switch which I hope will help increase this speed, though it is still 100mb to desktop.

[Peter Smee]

Cool I will try this on my network soon and let you know how it goes.

[Fog_Rookie]

Falko,
I am running into this same issue with my fog server. It seems at right around 20% my multicast speed has declined from 500Mb/min to less than 100Mb/min. I am also running Ubuntu 12.04, and would like to see if I can make it work without rolling back to 10.04.

I am somewhat unfamiliar with this part of your post “Using Webadmin, I logged into the mysql section created a new user (fogadmin) and password, giving this account full permission. I then edited the MYSQL info in /var/www/fog/commons/config.php + /opt/fog/service/etc/config.php. to match.”

If you can spare the time, could you elaborate a bit more about this process?

Thanks, in advance

[falko]

[SIZE=11px][FONT=Verdana][COLOR=#333333]‘Webmin is a web-based interface for system administration for Unix’[/COLOR][/FONT][/SIZE]

you can download it [URL=‘http://www.webmin.com/download.html’]here[/URL]

note that you can do what I said via commands but webmin is a pretty neat tool for servers without a gui

[chad-bisd]

I think slow multicast is usually do to kernel problems on the client or network misconfigurations. And the slowest multicast client will drag everyone down to their speed.

I can generally unicast 15 clients faster than I can multicast to them, because even with 15 clients active on a gigabit network, I’m getting 900MB/min to each client.

If you are sure your network is configured properly, then I’d try different kernels on the clients.

[falko]

Yes I must add whilst I had a good run with multicasting I now prefer to unicast.