Re: SlugOS 5.3: /var/volatile same as ramfs?

Jan wrote:
Unnecessary with recent SlugOS releases, including 5.3-beta.

> The rationale behind this is to minimize the writes to the memstick I am
> booting off. However, I realized that in 5.3, most sub directories in the
> /var tree actually reside in /var/volatile (sym-linked). After further
> reading online and in this forum, I have come to the conclusion that
> /var/volatile is in fact already an in-memory filesystem, is that correct?

Yes.  The major difference is that the "volatiles" mechanism is managed
by a startup script and a config directory.  This allows fine-grained
control over what is in RAM, vs what is persistent.  Read the comments
in the "volatiles" file in /etc/default/ for details for your
configuration.  (The configuration is selected based on how you did the
"turnup" command (turnup memstick vs turnup disk, for example) -- in
addition to selecting a different syslogd configuration, turnup also
selects different volatiles configurations.)

> How much memory does it take away from the RAM, and do I now need to employ
> log rotation and archiving strategies to make sure the volatile fs never
> fills up?

How much RAM it takes depends solely on how much you store in the
filesystem, but it will not exceed 1/2 of the physical memory available
(which works out to 16MB on an unmodified slug).  It is commonly abuse
of the /tmp directory that will fill up the space, so it is not usually
necessary to rotate logs and all that.  But feel free to do so if you wish.

>
> Also, is it still worthwhile to try to move /dev to a separate ramfs to
> further minimize access to it? I guess it's not necessary, as the access to
> /dev is mostly read-only, which is not a problem for solid state memory, is
> that correct?

Correct.  And it will be cached in any case, so unlikely to cause any
real concern.

> Under 3.10, I was actually booting off an external HDD, so it
> was important for me to minimize both reads and writes to it to allow for it
> to spin down after some idle time.

I'm glad you won't be going down that path any longer; spindown of HDDs
is a bad solution to whatever it is the real problem might be, and in
the end it solves nothing.  If you cannot live with a spinning HD, then
a solid-state device (USB memory stick or even an SSD) is the better
choice. :)

-Mike (mwester)