Re: SCSI vs SATA hard disks

On Tuesday 23 September 2008 14:03, someone identifying as *Haines Brown*
wrote in /comp.os.linux.hardware:/

Aragorn <aragorn@xxxxxxxxxxxxxxxxxxx> writes:

On Monday 22 September 2008 22:41, someone identifying as *Haines Brown*
wrote in /comp.os.linux.hardware:/

[...] I make my first partition at least 500 Mb so that I can do a base
installation in it using cdebootstrap. [...]

If you're concerned with having your system securely and properly set up,
then I would recommend that you split off as much from the (target) root
filesystem as possible at the root directory level and use custom mount
options for those filesystems.

No, I actually have 12 partitions at present that are broken out (3 of
which are custom). The root was made large so that it can serve as a
temporary installation partition, from which directories will be moved
out once the base system is in place there. However, it makes more sense
to use the swap partition for this purpose because these days it is
plenty big. I run a workstation rather than a server.

Or alternatively, you can create a second root partition, which you leave
unmounted once the system is set up properly. That way, you have a rescue
root filesystem for in the event something goes wrong with your main root
filesystem.

You bring up some interesting points about partitioning policy. Although
OT, I wonder how to implement /tmp as a tmpfs rather than ext3
on the physical disk and why this it is a good idea to do it.

Doing it is rather easy. Simply mount /tmpfs/ to it. Boot up in single
user mode, make sure */tmp* is empty and then and edit your */etc/fstab* to
include a line like this:

none /tmp tmpfs auto,nouser,nodev,noexec,nosuid,noatime 0 0

If so desired, you can also easily control the maximum allowed size of
*/tmp* in this manner by adding the /size=/ mount option - see the /man/
pages for details - so as to limit the available space for */tmp* without
having to set up quota or resize on-disk filesystems. The default maximum
size if no parameter is given will be half your available RAM.

The reason as to why one should make */tmp* a /tmpfs* is that according to
the FHS 2.3, nothing in */tmp* should be expected to survive a reboot.
It's normally only needed for sockets and such, and those things don't take
up much diskspace.

An issue that has always troubled me is the optimal sequence of
partitions. For example, /swap is supposed to be located in relation to
the physical disks on the hard disk, but I never knew how to do
that. Howver, I'm not sure it makes any difference any more.

Normally, manuals and installers will encourage you to create a swap
partition right behind the root filesystem - so as to make sure that you
don't forget creating one - but on systems with a lot of RAM, the location
on disk of the swap partition is not really relevant anymore.

It used to be relevant on older systems with less RAM because the closer the
swap partition is to the start of the hard disk, the faster it will be, due
to the fact that the outermost cylinders have more sectors on them than the
innermost ones, and thus more sectors can be read in one go without having
to switch heads or move the position of the heads over the platters.

I normally create */boot* as the first partition, followed by the root
filesystem itself. And as a third, I will then create either */usr* or the
swap partition. It has always proven to be a good set-up. :-)

--
*Aragorn*
(registered GNU/Linux user #223157)
.

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