Those of you running relays on low-RAM hosts, what do you do about DirCache?

When I first brought up my relay I noticed this message in the logs:

[warn] Being a directory cache (default) with less than DIRCACHE_MIN_MEM_MB MB of memory is not recommended and may consume most of the available resources, consider disabling this functionality by setting the DirCache option to 0.

When I DirCache to 0 I see another warning:

[warn] DirCache is disabled and we are configured as a relay. This may disqualify us from becoming a guard in the future.

As it turns out I can increase my VMs memory for free so that’s no big deal. Still, I’m curious. What do people do with relays without much memory? Skip DirCache? Are there ways to reduce the memory footprint and still cache directory info?

Thanks,

—mkb