Readyboost for Linux

[Fred Derf Veteran]

Well, I've got this PIII-800 with 192MB RAM with Knoppix on it and I don't feel like investing any money into something that is obsolete.

So I created a swap drive on a 512MB USB stick using the following commands (these commands will work on Debian/Ubuntu/Knoppix):

sudo mkswap /dev/sda1

sudo swapon -p 32767 /dev/sda1

It seems to work:

			 total	   used	   free	 shared	buffers	 cached
Mem:		190348	 186240	   4108		  0		  0	  49944
-/+ buffers/cache:	 136296	  54052
Swap:	  1031872	 112980	 918892

I also have 512MB of swap on the HDD but the priority is set to -1 (which was the default). It seems to be paging less. I believe this particular box is limited to USB 1.0 so it may not be helping the speed all that much but at least it makes less noise!

[kyro]

heh .nice trick, cant verify will it work or how good will it work. but logic is very nice.

[betamaxman]

Flash drive is nowhere near as fast as ram, and you are still only as speedy as the usb port as you pointed out, and even 2.0 is going to slow it down. But I concur, nice hack. :cool:

[sk8er_boi6000]

Readyboost is supposed to improve the speed of small, random IO operations. USB flash memory is terrible for large sequential R/W operations like paging, I cannot see this having the same kind of performance benifit as Readyboost, it would be like putting windows paging file on a USB drive

[markwolfe Veteran]

Cool. But like sk8r_boi pointed out, this is a swap usage. Microsoft's ReadyBoost is used as additional drive cache. There would be no data integrity issue for unexpected loss of ReadyBoost, but potentially dire consequences for loss of swap. :o

Plus, in order for a USB key to be used for ReadyBoost, Microsoft checks it to ensure it meets minimum performance requirements (random reads, etc.) before allowing its use. This should eliminate cases where ReadyBoost is enabled and actually slows down cache reads.

For me, I am happier with the performance of Linux's more sensible swap approach (direct partition access) over the Microsoft indirect (swap data must go through the NTFS file system handling, and deal with a "file" that is prone to fragmentation). It would be nice to see if there is a Linux system for handling an artificial increase to a Hard Drive's built-in internal cache. I did a quick google, but got too many results for me to care to waddle through them.

[kyro]

I wish this logic by fred can be used to do "application cache" (if i can put it that way). like when opening Gedit or Openoffice or Gimp or other apps which can benifit with this logic. as it is, linux apps are already fast and only few apps are MEM heavy (mozilla with plenty tabs , large images opened in gimp) etc.

hope i was able to put my point.

[neufuse Veteran]

Wouldnt this ruin your flash drive relatively fast if your page file got high usage? :blink:

[kyro]

pagefile is for windows, linux has swap (partition).

[Brian M. Veteran]

Nah, it shouldnt harm the USB stick although, unless your hard disk runs slower than 1.5MB/s, it will actually harm system performance.

[Marshalus Veteran]

Interesting idea, but as pointed out above it would probably be worse then just doing the regular ssetup. But with a system that old who cares :p

[tmahmood]

but won't this be useful in a live cd session?

[mehul]

Well if it's useful for installed distro then it will be useful for live cd too.

As it is live cd can use swap partition.

[betamaxman]

A live cd would be better served if the iso is placed on the flash drive and booted from there. or if booted from cd on a system with 2 or more gigs of ram and completely loaded to system memory and run from there . :cool:

[The_Decryptor Veteran]

I think LiveCD's put their swap on a RAM drive anyway (although only a small one)

And with only using USB1, it's going to slow it down.

[tmahmood]

  Quote

I think LiveCD's put their swap on a RAM drive anyway (although only a small one)

If you already have a swap drive live CD uses it, I've checked it at my dad's PC, that had 256MB RAM. So if this works it can be a good solution for systems that is low on memory.

[The_Decryptor Veteran]

Still better to have the swap partition on the hard-drive though, many times faster than a flash drive connected via USB1, and probably one on USB2 as well.

[Fred Derf Veteran]

Someone with USB2 and relatively low system memory should do some benchmarks.

[tmahmood]

  Quote

Still better to have the swap partition on the hard-drive though, many times faster than a flash drive connected via USB1, and probably one on USB2 as well.

Yeah, very true. But I'm thinking of the situation where the live CD installer takes like forever to start as the system have only 128MB & you don't have anything handy but a Linux terminal and you cannot modify the partition as you don't have any Idea what is in that damn thing and its not even yours... pretty complicated situation, heh ;)

  Quote

Someone with USB2 and relatively low system memory should do some benchmarks.

Yes please :yes:

[K3EnU]

what about trying something like that :

http://forums.gentoo.org/viewtopic-t-296892.html

mounting / into ram rather than swap on usb key would increase speed a lot !!

[Fred Derf Veteran]

  K3EnU said:

what about trying something like that :

http://forums.gentoo.org/viewtopic-t-296892.html

mounting / into ram rather than swap on usb key would increase speed a lot !!

That is designed to improve performance in systems with a lot of RAM. I was trying to improve performance in a system with relatively little RAM.

Obviously the best way to improve performance for my issue is to add actual RAM. I was looking for the "next-best" solution.

[Barney T. Administrators]

Thanks for posting this thread, Fred. We all appreciate new ventures that work........... :yes: Especially when they are posted for others to try...

[MrA]

  Fred Derf said:

Someone with USB2 and relatively low system memory should do some benchmarks.

You don't even need to have a low amount of memory. There's a kernel startup option that artificially limits the amount of memory Linux uses. I don't remember what it is, but you can google it.

EDIT: I'd do it, but I'm one of the few 'tech people' that doesn't own a flash drive.

[betamaxman]

  The_Decryptor said:

I think LiveCD's put their swap on a RAM drive anyway (although only a small one)

And with only using USB1, it's going to slow it down.

Sorry, what I meant was that only a live cd image running from a usb will see any usb benefit, in that running from the flash device is the only benefit, as it is faster than running from cd. Didn't mean anything about swap. Again apologies. :cool: