[OpenIndiana-discuss] Swap during install

[Jan Owoc]

On Mon, Sep 24, 2012 at 6:43 AM, Reginald Beardsley <pulaskite at yahoo.com> wrote:
> --- On Mon, 9/24/12, Gabriele Bulfon <gbulfon at sonicle.com> wrote:
>> I noticed that I usually have to grow the default swap
>> installed by OI or XStreamOS, because the
>> default text installer set up following some rules (stated
>> inside the python sources):
>> memory        type
>>      required    size
>> --------------------------------------------------
>> 900mb-1G      zvol
>>     no          0.5G
>> (MIN_SWAP_SIZE)
>> 1G-64G        zvol
>>       no
>> (0.5G-32G) 1/2 of memory
>> 64G          zvol
>>         no
>>   32G (MAX_SWAP_SIZE)
>> I find these settings very limiting, as I remember being
>> told for Solaris 10 to make swap double the available RAM
>> (while here it keeps it half).
>> What do you suggest?
>
> My personal rule is 4-8x.  Disk is cheap and this facilitates keeping lots of large processes in the process table.
>
> The correct answer depends upon how you are using the system.  Note that you can never have too much swap space, but you can have too little.

I agree that the "correct" answer, if one exists, depends on system
use. I would imagine a text-only install used as a file server (or
other simple tasks) is unable to use more than 1-2GB of swap, so I
would set swap = 2x RAM, to a maximum of 2GB :-).

Would it be best if the installer give an option of setting the swap
size (I'd be annoyed if my file server installer decided to eat up
200GB of disk space for swap), mentioning some general guidelines? Or
is the size of swap easily changed after installing (this is the ideal
case, as I might not know the amount of swap I need until I've
installed and run some benchmarks)?

Jan