[ltp] Flash HD in R51 (via CF and ultrabay)

[Richard Neill]

Laurent Gilson wrote:
> Hello,
> 
> i plan to upgrade my R51 with a flash-based HD and i'm seraching
> for the cheap way out. I only need ~2GB space and speed is not the
> real problem. I'm well aware of the limited-number-of-writes problem
> and plan to use a wild combination of RAMfs, unionfs and 2 GB RAM.

What are you trying to achieve?  The IDE-adapter/CF approach will give you:
   Silence
   More Physical resilience
   Much faster seek time (but possibly slower writes). Boot time is 
about unchanged.
   Cooler running, much lower power consumption.

> So i'm thinking about a CF <-> IDE adapter 

I've done this with an X20, and it works really well. I now have a nice, 
totally silent media centre :-) In my case, I simply put the CF card + 
adapter into the regular HDD slot.

(like this:
> http://www.mini-itx.com/store/?c=16#p2620 ) 

You can buy these new on eBay for about $3.

> 
> 2. Do these HDD adapters show up as a real, normal IDE-HD ?

Yes, these work exactly like a normal IDE disk. The OS can't tell the 
difference. [In some cases, you can't enable DMA with them, but it 
doesn't seem to make a big difference in practice]


YMMV about whether the thinkpad will boot with ONLY an ultrabay device 
and no device in the normal HDD socket.. It seems to be thinkpad 
specific - certainly when I tried the X22 with USB boot (which normally 
works fine), the BIOS failed if the HDD socket was empty.


Caveats:

i)You may want to back up your *data* elsewhere periodically - since CF 
cards aren't all that reliable, especially with a journalling FS. But 1 
million writes is still a pretty good lifetime. It depends on your 
application: for the media centre, I don't really care if the disk dies 
in 2 years, since all I'd lose is the OS itself; my data is on NFS.


ii) The physical mounting of a CF/IDE adapter isn't that great. I advise 
some foam packing to help it stay put.  You'll also need to insulate the 
bottom of the adapter PCB with something. [Eg a plastic sheet cut from a 
CDROM wallet. Don't use insulating tape - it disintegrates over about 3 
months]

iii)The HDD plastic cover is normally fixed to the HDD itself. So, if 
you want to hold this in place, you'll need some workaround. I just made 
an interference fit with some expanded polystyrene foam, which is fine 
for me, since I never move the machine.



HTH,

Richard