Manual Installations on Flash Media

[David Allen]

On 8/3/09, Polytropon <freebsd at edvax.de> wrote:
> On Sat, 1 Aug 2009 14:21:02 -0700, David Allen
> <the.real.david.allen at gmail.com> wrote:
> > I need to create a FreeBSD installation on an SSD drive (connected via
> > a USB adaptor), and would like to do so manually so as to avoid the
> > use of an installation CD, PXE or sysinstall.
> >
> > 1.	Would a device alphabetical order (as used by bsdlabel) work?
>
> I think it's no problem. My /etc/fstab looks that way:
>
> 	/dev/ad0s1b     none           swap    sw        0       0
> 	/dev/ad0s1a     /              ufs     rw        1       1
> 	/dev/ad0s1d     /tmp           ufs     rw        2       2
> 	/dev/ad0s1e     /var           ufs     rw        2       2
> 	/dev/ad0s1f     /usr           ufs     rw        2       2
> 	/dev/ad0s1g     /home          ufs     rw        2       2

Knowing that will make things easier when editing the disklabel and
adding corresponding entries in fstab.

> > 2.	I don't expect the system to swap, so can I dispense with a swap
> > entry and have everything function normally (no error messages, etc.)?
>
> I don't know how to "expect" swapping. As far as I understood, the
> system decides by itself if to write data to / read data from the swap
> file.

Something got lost in the translation.  "I don't expect" is an idiomatic
form of "I estimate a low probability of swapping".

> I'm not sure if you can omit it.

Haven't done an actual NanoBSD installation on flash, but my reading of
the setup is that there is no swap partition whatsoever.   Guess I'll
have to experiment to find out for myself.

> > 3.	Will adding `noatime' to / or any other filesystem have any
> > consequences?
>
> Yes. The access time for files won't be recorded. Using the noatime
> option is often advised for the use with SSD media, so is ANY advice
> that helps to minimize read / write cycles in order to increase the
> life time of the media.

Just wanted to be sure.  I'm still open to using md devices for /var and
/tmp (with a cron-ed sync to disk) possibly in conjunction with remote
logging, but one of the reasons I opted for SSD over regular flash is to
avoid that extra layer of complexity.

Thanks for the reply.