# Do jails support SMP?



## estrabd (Feb 2, 2016)

Background:

I am on FreeNAS (9.3, latest at the time of this writing), and I am having an unusually hard time determining if the jails I am creating through it are providing SMP access for threaded processes.

Question:

Concurrently (no pun intended), I am trying to find any document on the web that discusses how/if SMP is supported inside of a jail (currently I am constrained to FreeBSD 9.3 since this is a FreeNAS box).

Any pointers would be appreciated.

Update:

Sorry for the noise; apparently I was able to conclude that it is supported by running pigz on a very large file, both inside and outside of the jail, whilst observing the output of `top -P`.

TIA,
estrabd


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## SirDice (Feb 3, 2016)

Technically a jail runs on top of the host's kernel. So if the host's kernel supports SMP the jail will too.


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## kpa (Feb 3, 2016)

Jail is not a virtual machine, all jailed processes are scheduled using the host's process scheduling with equal priority with the host's own processes.


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