Gentoo Archives: gentoo-user

From: Paul Hartman <paul.hartman+gentoo@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] SSDs, swap, caching, other unusual uses
Date: Mon, 01 Aug 2011 16:31:35
In Reply to: [gentoo-user] SSDs, swap, caching, other unusual uses by Michael Mol
1 On Fri, Jul 29, 2011 at 1:18 PM, Michael Mol <mikemol@×××××.com> wrote:
2 > Something that's been tickling my brain for a couple years now, and
3 > you guys are probably the right ones to ask.
4 >
5 > I haven't dropped coin for an SSD (yet), but I was wondering about
6 > uses for them beyond using them for / or /home.
7 >
8 > 1) What about sitting swap (partition, file, whatever) on the SSD?
9 > Presumably, in scenarios where expanding the RAM in a system is
10 > prohibitively expensive, an SSD could reduce the impact of swap
11 > thrash.
13 Swap on flash memory is faster than on disk, but it is still swap and
14 still sucks. :) There's no reason why it won't work, but I doubt it'll
15 have as much of a positive impact as you're hoping. In fact depending
16 on the SSD some don't cope with a storm of tiny simultaneous random
17 reads and writes and might block even worse than a fast HDD. IMO.
19 > 2) While my system rarely goes above using 2-2.5GB of RAM, I enjoy
20 > having 6-8GB of RAM, just for the file cache. Of course, I lose that
21 > when I reboot; the cache needs to be repopulated. Has there been any
22 > work in the kernel for doing things like Vista/Win7's ReadyBoost?
23 > ReadyBoost has a ridiculous limit to only using 4GB of a flash drive,
24 > but I'd think that an 80GB SSD would be a massive performance
25 > improvement.
27 I believe DM-Cache provides this kind of functionality in Linux. I've
28 never tried it.
30 You can also buy a hybrid hard drive, it is a traditional HDD with SSD
31 built-in for caching. That is transparent to the operating system.


Subject Author
Re: [gentoo-user] SSDs, swap, caching, other unusual uses Michael Mol <mikemol@×××××.com>
Re: [gentoo-user] SSDs, swap, caching, other unusual uses Stroller <stroller@××××××××××××××××××.uk>