speeding up disk-based laptop by moving /usr to flash?

[Jerry Feldman]

I don't think that would affect performance, and may even hurt
performance. Remember that when Linux loads a program or a shared
library, the location of that program or shared object effectively
becomes part of swap. The program and its dependent shared libraries are
mapped into memory, but only loaded into pages when needed.

Boot time is really a few stages, first, the kernel is loaded and single
user mode is started, so a few shared libraries are needed. Then the
transition into multi-user mode. Lots of things are done at this point,
and there are some bottlenecks.

Also remember that the amount of available RAM affects performance
probably more than anything else.

What I would do is to look at possibly replacing the X41 since prices
are now very low. Most new laptops today are built for Windows 7 which
requires more memory so those laptops have more memory builtin.

But, first, analyze your boot time by looking at the time each step takes=
=2E

If you want to keep the X41, what I would do would be to get a new
battery, and if need be a new hard drive, and maximize the memory.

On 12/02/2009 12:19 AM, Brendan Kidwell wrote:
> At the last BLU meeting I was thinking out loud about buying netbook, b=
ut
> I'm leaning away from that now. I think someone mentioned here "the key=
board
> is just too small," and I'm starting to think the lack of 4:3 aspect ra=
tio
> netbooks is really a dealbreaker for me. I need my 768 lines.
>
> I currently use Ubuntu 9.10 on a Thinkpad X41 Tablet.
>
> I've thought about replacing my hard drive with an SSD device, but I'm
> reading a lot of FUD that's giving me... well FUD. It seems that the ch=
eap
> SSD devices are unreliable and of unknown origin (a lot like CD and DVD=

> blanks) and unfortunately have a tendency to NOT report read and write
> errors. Eek! Don't put your data there. And premium SSD devices are jus=
t too
> expensive to justify for a home user.
>
> So here's a possible plan I conceived tonight: My goals are to maximize=
 the
> perceived performance of my Thinkpad as well as maximizing battery life=
=2E
>
> 1. Buy a fresh battery. (No question about this step; the current one i=
s
> weak and years old.)
> 2. Keep the 60GB parallel ATA (IDE) hard drive and keep most of my stuf=
f on
> it.
> 3. Install a 16GB "133x" (20MB - 25MB per second) CF card in a PCMCIA-C=
F
> adapter in my PCMCIA slot. -- I never use the slot for anything else.
> 4. Move /usr to the CF card and mount it from there with "no access tim=
e
> recording" switch. Maybe also /var and /etc.
> 5. Maybe try putting /tmp in a RAM disk. (See what uses /tmp first and
> determine if it's worth carving out the block of RAM.)
>
> Most of the parts of the OS that don't live in /usr and /etc and /var l=
ook
> like they're small enough that moving them off the disk isn't worth it,=
 and
> at this point I think I want to keep my data on the disk.
>
> I'm guessing this will improve my boot time as well as startup time for=

> applications by virtual of the fact that flash memory generally has muc=
h
> faster seek time than a disk.
>
> My concerns are:
>
> - Will keeping a CF card in a PCMCIA adapter online consume a lot of
> additional power?
> - Will the maximum throughput of the CF card be so slow as to overshado=
w the
> expected reduction in seek time?
>
> Has anyone ever tried anything like this?
>
> Would I get different performance from using an SD card in the SD slot?=
 From
> what I read tonight it seems the "Secure Digital" interface has even mo=
re
> limited bandwidth than a typical CF card.
>
>  =20


--=20
Jerry Feldman <gaf-mNDKBlG2WHs at public.gmane.org>
Boston Linux and Unix
PGP key id: 537C5846
PGP Key fingerprint: 3D1B 8377 A3C0 A5F2 ECBB  CA3B 4607 4319 537C 5846