FLASH disk as swap

[der.hans]

Am 03. Dez, 2009 schwätzte Marco Savo so:

moin moin Marco,

> I have a *simple* question:
> it is possible use a FLASH drive as SWAP? someone told me that there

It's absolutely possible.

> is a limited numbers of write that is possible doing, so that will
> reduce the life of the flash. But what about SSD hard drives then? are

The short answer is that you should be fine with recently purchased solid
state cards and drives. The long answer was provided by Alan Dayley,
search the list archives for his posts.

> not NAND flash as well? and which is the best filesistem to use then?
> (UBIFS? EXT4?...)

It was already adressed that swap creates it's own filesystem.

> Oh obviusly... but why we need a swap?

For the most part Linux will work just fine without swap, but there are
tiems when swap is really useful. For the most part hard drives are cheap,
so giving up space for swap is irrelevant :).

Most SSD drives are not inexpensive and tend to have small capacity
compared to platter drives. If you need to hibernate then you'll need enough
free swap space to save the ram contents to swap space.

Having swap be 1.5 times the size of ram is good, double the size of ram
is better.

> I hope you like my questions, maybe one day I can also provide answers...

Questions can prompt for answers, which is good :).

ciao,

der.hans
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