Our new X8M Exadata’s backup to ZFS appliances via Top of Rack switches, however so far they were not using jumbo frames. On the ZFS appliances changes have to be done but also on the KVM host/guests.
We are running our X8M with virtual machines and that now uses KVM instead of XEN.
There are two changes to do one on the KVM host and one on the KVM Guest.
On the KVM host
#### DO NOT REMOVE THESE LINES ####
#### %GENERATED BY CELL% ####
DEVICE=beth34
USERCTL=no
BOOTPROTO=none
ONBOOT=yes
BONDING_OPTS=”mode=802.3ad miimon=100 downdelay=200 updelay=200 lacp_rate=1 xmit_hash_policy=layer3+4″
BRIDGE=vmbeth34
NM_CONTROLLED=no
MTU=9000
On the KVM Guest
1. shutdown the KVMGuest
2. detach the bridge – configuration file for bridge is in /EXAVMIMAGES/GuestImages/${KVMGuest}/ –
vmbeth34.xml in my case
cd /EXAVMIMAGES/GuestImages/${KVMGuest}
virsh detach-device ${KVMGuest} $(pwd)/vmbeth34.xml –config
3. modify the configuration file of the bridge
vi vmbet34.xml
add the line
<mtu size=’9000′ />
4. attach the bridge to the KVMGuest
virsh attach-device ${KVMGuest} $(pwd)/vmbeth34.xml –config
5. start the KVMGuest
*******
You can now ping your zfs appliance ( if jumbo frames were enabled there ) as described here
