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Re: [LUG] De-bottlenecking

 

> Sent: 24 September 2014 00:26

A completely normal time of day :)


> Interface speeds are irrelevant, it is the speed they are running at.
> Mis-negotiating is common but 3MB/s is neither 10Mbps or 100Mbps.
> However always worth checking the current settings.
> Amazing how many use to negotiate sub-optimal settings, things are better these 
> days but I always check when troubleshooting network speed issues.

Now then... 1Gb interfaces... the IEEEEEE regs basically say "you can't fix the NIC 
to 1Gb/Full", so it /should/ be auto-neg... 
However, I've found that one machine is auto-neg'd to 100/Full - whether that's 
because of the Netgear switch, I'm not sure. It's a "pro" (managed) switch which can 
have the ports forced to a speed / duplex, but it's complying with the network 
police - there's no 1Gb/Full - just 10Half/10Full/100Half/100Full/autoneg ... so 
something's being a silly sausage there. (intense swearing replaced for the younger 
audience)



> Any time someone says rsync is slow ...
> Old fashioned "ftp" (if security can be constrained) is a good choice.
> Or Google using netcat for the same sort of thing.

Hmmm... good idea. I'll give it a go.

> Traffic shaping (protocol specific) can of course fool this approach, but 
> hopefully you know if traffic is shaped.
None of that internally...

> Other common issue is write performance sucking due to sync issues with data or 
> metadata.
> bonnie++ will tell you if your IO sucks. But also iotop and sar should show you if 
> it is doing insane IO behaviour during the rsync.

Cool... that's great. I'll have a look in to them and suss it out.

THanks!!!


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