Disable TCP checksum offloading on KVM virtual network

Question

I am trying to run a query where we find movies based on an actors name. When I run

SELECT known_titles
from name_basics
where name like 'Tom Cruise'

The datasource we have returns a single TEXT field of tt0181689,tt0092099,tt0116695,tt0325710.

How could I use this to query again? My main query is:

SELECT movie_name
from MOVIE_INFO
where movie_id like (SELECT known_titles
                     from name_basics
                     where name like 'Tom Cruise'
                    )

But this is returning nothing. Is there a way I can do a movie_id wildcard search in PostgreSQL that will see what is similar? Something like SELECT movie_name from MOVIE_INFO where movie_id in tt0181689,tt0092099,tt0116695,tt0325710?

The list of tt0181689,tt0092099,tt0116695,tt0325710 is stored as TEXT in a single cell and is copied from a CSV file using PostgreSQL \copy command.

Solution 1

ethtool -K eth0 tso off in rc.local or the vm startup script. You could probably do it as a libvirt hook too

Solution 2

I recommend doing this with a udev rule. I put this in /etc/udev/rules.d/81-bridge.rules:

ACTION=="add", SUBSYSTEM=="net", NAME=="virbr*", RUN+="/sbin/ethtool -K $env{INTERFACE} tx off"

More sophisticated approaches are possible, depending on your needs.

Comments

[Michael Hampton]

You want to disable offloading on a virtual network?!

[Ryan Babchishin]

@jackhab Weird problem. How did you notice it? I'm just curious.

[jackhab]

@RyanBabchishin well, I noticed HTTP requests are stuck so I looked at the traffic in Wireshark.

[Shameel]

It is difficult to say why your query returns empty without seeing the structure of your tables and your data. I suggest you manually query the data using the output of the first query to make sure that your column data does not have leading or trailing spaces. I suspect that the issue is with the data.