[vdr] Change recording keep-time?

[Matt Tovey <Matt.Tovey@sgi.com>]

Hi,

can someone tell me how/if I can change the keep-time of a recording,
after the recording has taken place?

I don't want my recordings to be automatically deleted (I'd prefer to
clean then out myself), and I've a few recordings that were made with
the default setting of 50.

I'd like to change these to '99', but I can't find where this value is
stored...

Thanks!

Matt