topic Re: bootarg.init.low_mem in Simulator Discussions

bootarg.init.low_mem

papadopoulosa — Thu, 05 Jun 2025 05:34:27 GMT

I'm trying to find out if I need to change this setting. I've provided 4GB's of RAM for my vSIM's, but I keep seeing this setting and wonder if it restricts performance of the vSIM since it is only allocating 512MB for the FreeBSD portion.

Are there any other performance improvements I can make by changing any of the configuration options?

Re: bootarg.init.low_mem

shatfield — Fri, 13 Jun 2014 17:34:45 GMT

If you gave your vsim 4gb, you can set that value to 760 or just unset it. It restricts the ram available to the bsd environment to keep ontap functional when its only got the default 1600mb to work with.

Re: bootarg.init.low_mem

papadopoulosa — Fri, 13 Jun 2014 18:18:50 GMT

So is it best to leave it as is and provide CDOT the memory, or will it help to unset it?

Thanks for the answer Sean.

Tas

Re: bootarg.init.low_mem

shatfield — Fri, 13 Jun 2014 18:31:31 GMT

Hard to say, really.

Leaving it trimmed to 512 may give ontap more ram for caching which should help performance

Leaving it trimmed to 512 may cause additional swap activity which should hurt performance

All the jumbo 4gb vSIMs I've seen have it set to 760.

Re: bootarg.init.low_mem

papadopoulosa — Fri, 13 Jun 2014 19:03:55 GMT

Thanks Sean. That works for me.

Re: bootarg.init.low_mem

papadopoulosa — Fri, 13 Jun 2014 19:15:32 GMT

Sean:

I changed the value, and it had the effect of causing the filer to panic on bootup. I changed it back to 512.

Re: bootarg.init.low_mem

shatfield — Mon, 16 Jun 2014 07:36:40 GMT

I couldn't get mine to panic, but its CDOT8.2.2RC1. What mode/version are you running?

Re: bootarg.init.low_mem

papadopoulosa — Wed, 25 Jun 2014 14:45:32 GMT

CDOT 8.2.1