Even though the switch may support it,
some switches still have problems with Jumbo Packets and can choke on the heavy
traffic. I don't believe that the filer has an issue with MTU of 9000, but as
Matt pointed out, I'd check the info on your linux distro as well.
From:
owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Matthew Zito
Sent: Tuesday, February 26, 2008
11:32 AM
To: Brent Ellis;
toasters@mathworks.com
Subject: RE: Jumbo Packets with
netapp FAS3050
We've always put our MTU size at 9000, because we're
primarily database-oriented. However, I have no idea if Linux can support
the larger jumbo frames. 9000 definitely works though, and lets 8k
database or filesystem blocks fit within one frame, so there's no
fragmentation.
Thanks,
Matt
--
Matthew Zito
Chief Scientist
GridApp Systems
P: 646-452-4090
mzito@gridapp.com
http://www.gridapp.com
-----Original Message-----
From: owner-toasters@mathworks.com on behalf of Brent Ellis
Sent: Tue 2/26/2008 9:28 AM
To: toasters@mathworks.com
Subject: Jumbo Packets with netapp FAS3050
Hello All,
We have been using our netapp primarily for NAS storage, but I am
experimenting with iSCSI now for some specific applications. I
managed to create a bit of a network issue recently when I tried
enabling jumbo packets on my netapp and my test server. The iSCSI
connection kept resyncing and was not stable. I think this was
because I didn't create a separate vlan for the devices using jumbo
packets. Upon further research, I found mention that some devices/
oses calculate the checksums differently and that can affect the max
packet size. Does anyone have any recommendations for a packet size
for both the netapp and for my linux servers? is 10240 a safe
bet(max
size supported by my switch) or should I use something like 9000 or
8192? Should I use a different packet size if I am connecting a
target to a windows box? I would ideally like to make a jumbo
packets
vlan and just set all the devices on that vlan to a larger MTU, but I
don't want to create a network traffic problem in the process.
Brent Ellis
Systems Analyst/Consultant
CAS Computing Services Group
interi@bu.edu