Use Flash memory as swap space in YDL

[H.axen]

Unfortunately, because Linux on the PS3 is running under the hypervisor, the disk access speed is very slow, video is confined to framebuffer only and is very slow as well, and the system memory is extremely (only 256 megs are made available to Other OS from the hypervisor).

With these memory limitations, the system swaps a lot using the hard drive for extra memory space. With slow disk IO (26MB/s!) starting and even using programs can be a real pain.

We can use flash storage to improve this. Since flash card access is also quite slow also we can use 2 storage devices: a 512MB SD card and 1GB usb stick.

Under this example the SD card shows up as "/dev/sdd" and the USB key as "/dev/sdf", these might not be same for you. Here is how to set it up:

This presumes your flash devices have been previously formated for you and contain a partition table. WARNING! This procedure will destroy all data on the SD card and the USB key! Open a terminal

Enter the following commands:

su
[type in your root password]
/sbin/mkswap /dev/sdd1
/sbin/mkswap /dev/sdf1
/sbin/swapoff -a
/sbin/swapon -p 1 /dev/sdd1
/sbin/swapon -p 1 /dev/sdf1

You are now running with swap space evenly distributed between the two flash devices. If you like it we continue the procedure: edit the following file:

/etc/fstab

remove the line that contains the word "swap" in it. Add these two lines instead:

/dev/sdd1 swap swap pri=1 0 0
/dev/sdf1 swap swap pri=1 0 0

You are done!

thankyou to Ilian Tzankov

[FREEXTER]

how does this work for ubuntu 7.10

[JamesDykhuizen]

what about if u dont have a sd card? same thing?

[Renomune]

Would more flash drives be fesable? like all 3 card slots and a usb or 2?

What would you use in terms of size? 4-8 gigs? Because I get rid of the small ones when they are trippled to qadruppled.

[oobuk]

Flash memory has had some limitations with regards to rewrite and sector life expectancy.

Before you use Flash Memory as swap (lots of rewrites) you should familiarize yourself with the issues with Flash Memory life expectancy in high rewrite environments.

Make sure your flash is of recent manufacture. Flash memory from a few years ago may not survive very long on a very busy machine.

[tapani]

Hi,

Would I gain anything by installing the whole yellow dog 6.0 on a usb flash drive (corsair flash voyager GT) it is fairly fast for a usb-drive (34 MB/s read and 25 MB/s write). Then I could actually take swap out of use ?

What do you guys think?

I was also planning to use a CF to SATA adapter, but then I read from this thread that the disk access would be too slow anyway? Maybe there would be some gain in access speeds though ? Or maybe they could even be combined...

If I had a 8 GB CF connected to SATA adapter and installed a YDL 6.0 on it.. wouldn't that make the swap useless if I just wan't normal desktop/mediacenter use?

I have already made my YDL quite light by using Fluxbox as the window manager and disabling the GDM.

Please comment if you have any better ideas?
Where could I get the actual numbers about the hypervisor limitations for PS3 I/O transfer rates?

-Tapani

[tapani]

This would of course lead to a "faster" PC. (which I am also planning to try out)
I just don't understand why Sony allows PS3 to run linux or other OS:s but then restricts the already somewhat limited hardware to gain an awful user experience?
Maybe they want to make their own OS and UI look faster ?

And what's the deal with Sony adding some flash memory on the new version of the PS3? I'm guessing that they will restrict it's use as well the same way they do know on other flash memory...

Just my two cents.. (or probably less)