Convert VIF interface to use a single interface without downtime

[jimmyjump75]

Hello,

I have an FAAS270 filer that is configured with a VIF interface that aggregates the two Gigabit Ehternet ports into one virtual interface.

I need to dedicate one of my two interfaces to iSCSI traffic and so I need to break the VIF and go to a single NIC. I will be doing direct iSCSI from a host to the filer, the filer will serve the targets.

Can I move from the VIF to a single interface without losing connection or without downtime?

If this is possible does anyone know the steps or have a doc listing the steps?

Also I will be doing a direct iSCSI connection from this interface that I free up. I do believe that the FAS270 supports direct iSCSI connections. Does anyone have any experience with direct iSCSI to another host and if so do they see any potential issues with doing this?

Thank you

Jimmy

[scottgelb]

You have to destroy the VIF so there is downtime.  If this is a cluster you can do it with a takeover/giveback.  Direct connect iSCSI works fine...don't see any issues there.

If you can keep the VIF... ONTAP support multihoming if you want multiple ips using ifconfig alias...but sounds like you need a direct connect... but a dedicated gigabit port doesn't do much for a 270.  On a good day about 40MB/sec write and 80MB/sec read.

[jimmyjump75]

Scott,

OK thank you for your time first of all.

The 80MB/sec MAX read is pretty much because of the 66% link efficiency of the single Gigabit interface? Gigabit with no TCP overhead would be about 120MB/sec just going off the number of bits. Is the 40MB/sec write due to the disk mechanics? In any case the 40MB/sec will be an improvement over what I get now believe it or not.

So I was thinking that instead of deleting the VIF I could just remove an interface from it and then use that interface for iSCSI traffic. Reading the man page I cannot remove the interface without bringing the VIF down. This is not an option because I am remote so I plan to edit the etc/rc file and reboot.

But what I cannot find in the man page is if you can create a VIF with only one interface. This is a FAS270 so only 2 NICS unfortuantely so I don't know if using the etc/rc file creating a VIF with one interface will work.

Here is my etc/rc now..

hostname filera

vif create multi filera -b ip e0a e0b

ifconfig filera `hostname`-filera netmask 255.255.252.0 wins

ifconfig e0a down

ifconfig e0b down

route add default 172.16.55.254 1

routed on

Here is what I was thinking to change it to (almost identical except that I remove the e0b)

hostname filera

vif create multi filera -b ip e0a

ifconfig filera `hostname`-filera netmask 255.255.252.0 wins

ifconfig e0a down

ifconfig e0b down

route add default 172.16.55.254 1

routed on

So my plan is to the etc/rc file and reboot.

What do you think Scott?

Thank you

Jimmy

[scottgelb]

You can create a single mode vif with one interface...doesn't make sense to do it unless you know you will add to it later... but in your case to remove an interface makes sense for it.. so in this case you could modify it hot but be careful and use the BMC in case of any issue... you have the BMC configured I hope and if not set it up with "bmc setup" and connect a 100MBIT link for a remote console.   As far as performance... the 270 is a great little machine but is a small blade module in a ds14mk2 shelf... it is a broadcom MIPS CPU and not a high end system.

[aborzenkov]

use the BMC

FAS200 did not have any BMC. Unfortunately. I could use some at the time

[scottgelb · Accepted solution]

I was thinkig 2000... yep.. no bmc..  definitely have a console ready in case of any issue or you won't be able to get back in the system.