Troels - zfs swap on FreeBSD

New About Yours API Help
1.6 KB, Plain text
Hello Allan and Benedict.
First of all, thanks a lot for a really great show. The two of you do a phenomenal job! :-)

I got a question primarily for Allan regarding ZFS and swap on FreeBSD.

Back in 2011, when I first started using ZFS on FreeBSD (I think it was 8.1-RELEASE), I initially installed it with my swap space in my ZFS pool. Sometimes the system would hang, and be entirely stuck except for responding to pings. I discovered that this was likely due to my swap space being located in my ZFS pool, the explanation I found back then went something like "ZFS needs to allocate memory to do I/O operations, but the swap space is needed when there is no memory available", and ever since then, I have always used a pair of regular "freebsd-swap" partitions in a gmirror setup to handle swap.

Recently, I have been seeing some people say in the FreeBSD forums that this is no longer and issue, and I seem to remember that Solaris-based systems uses ZFS for swap space. However, I have also noticed that the FreeBSD installer in 11.1-RELEASE uses regular "freebsd-swap" partitions for swap even when selecting to use ZFS.

It would be really nice if you could clarify the current state of ZFS and swap on FreeBSD, and how the problem have been handled if it has indeed been solved, and what you would recommend as of today. Should I continue with my gmirror setup for swap (Recently, I also added GELI into the mix for encrypted swap) for the foreseeable future or could I use ZFS for swap as well?

Thank you very much in advance, and keep up the good work that you do.

Best regards,
Troels, Denmark.
Pasted 9 months, 1 week ago — Expires in 85 days