[gentoo-user] Re: separate / and /usr to require initramfs 2013-11-01

[James <wireless@tampabay.rr.com>]

Gregory Shearman <zekeyg <at> gmail.com> writes:


> Both servers are running Gentoo Stable... therefore current kernels (for
> their architecture). Both have external HDD attached via USB.

Hey Greg,

If you just "reply" to the thread, we can keep one continuous 
thread going in lieu of a new posting each time.

Let's just look at the Panda board. I have a first rev panda to
experiment with. 

So a HDD via USB 2.0? fast enough for a Postgrsql database?
A bit more on the HDD setup (hardware) would be keen. 
Did you ever try to run this on a straight USB stick and not
the performance difference?


> File systems: root filesystem is on an SDHC card (2nd partition). Other
> filesystems (except for the boot partition) are all on LVM. I have
> /usr/src, /usr/portage, /usr/portage/distfiles is a symlink to
> /var/www/localhost/gentoo/distfiles (another filesystem). I also have
> /var/tmp/portage on a separate filesystem and I also run a postgresql
> database server which also has its own partition on
> /var/lib/postgresql/≤version>. Both servers have the same setup as I'm
> currently in the process of replacing the sheevaplug with the panda.

Postgresql on a separate partition, nice idea. Do you aggresively
manage  the PG server or is it just a recreational (light duty)
usage?

>
> Grub? There's no such thing on ARM machines. The kernel or uImage looks
> for the first partition on the configured root device (SDHC on my
> systems) the first partition MUST be VFAT (unfortunately) and it
> contains the u-boot bootloader and the kernel (uImage). 

https://wiki.linaro.org/LEG/Engineering/Grub2

https://wiki.linaro.org/LEG/Engineering/Kernel/ACPI/AcpiOnArndaleUefi

> Kernels are built the same way as x86 kernels except you do 
> "make uImage" instead of "make bzImage".

You Compile the kernels on a x86 host or compile them directly on
the Arm chip?

Then you put new kernels on the SD and swap those out to test/use
newer kernels on the Arm systems?


> LVM? All the above filesystems, except the root partition and the boot
> partition are LVM volumes. Filesystems are mostly Ext4 (very
> conventional).

What, no ZFS.....? Wait till Alan heards about this.....
Grub2 on ARM will allow many new file systems, and that
is the key issue with robust Arm servers, right now, imho.

> > Typical usage?

> Print server, database server, backups, webserver - which 
> includes serving gentoo portage and distfiles to other machines 
> on the network (THTTPD is a great minimal web server).

> > Any suggestions on setting up ARM servers, cluster,
> > and such are most welcome.

> ARM servers aren't much different to other servers but you must realise
> that these are low powered devices (the ones I run anyway) and aren't
> really suited to large loads. They especially suit a small business or
> home hobbyist environment. Even so, compiling Gentoo, especially on the
> Panda is not a problem and doesn't take forever (except for gcc
> updates ).

What does your make.conf look like on the panda?

> I suppose you could cluster a number of these devices but I think it
> would be more efficient to use a more powerful server running servers as
> virtual machines.


No BTRFS or CEPH?  (just teasing, but seriously....)

http://armservers.com/tag/ceph/
http://www.inktank.com/calxeda/

I posted previously on some Arm (A15) based systems, you may want to
look at for your next arm server, recently. Many have SATA 3 interfaces.

If you look at the ARM installation (handbook) docs, it is need of a
re_vamping.   I'm certain that folks would appreciate your
participation in the modernization of the ARM handbook, via the
Gentoo wiki.   The Gentoo wiki is your (ARM) friend....

I'm very happy, you are sharing your (ARM) gentoo experiences herein.


James