Re: How do I determine appropriate swapspace settings? And other partitioning questions.
From: Richard Eggleston (richard_at_spambin.richardeggleston.com)
Date: Tue, 08 Feb 2005 21:04:29 +0000
On Tue, 08 Feb 2005 14:30:22 -0600, Morningdew wrote:
(Apologies for top posting,)
I was told that twice the RAM is a good rule of thumb, upto a max of
I guess that much more is a waste of resources
L & P
> I was just curious to know... What are some good rules of thumb for
> configuring swap space under Linux? For that matter, are there any
> comprehensive guides or articles on the subject? When I used to admin
> NT boxes I used to set their "virtual memory" setting to 1.5 times
> physical memory, giving 50% over physical as swap. That was just by
> convention, or, "rule of thumb". No great scientific methodology, it is
> just what had worked for me and my coworkers for so long. Granted,
> Linux is different.
> On my box I have installed Ubuntu and moved up to the 2.6.10 kernel, if
> that matters. I am presently running on two IDE hard drives, 30Mb
> Quantum Fireball and 60Mb Seagate ST360020A. As it stands, I have 1Gb
> of physical RAM and have two swap partitions, one on each drive and both
> 494.16Mb. Initially I had set up a 32-bit install on one drive, and a
> 64-bit (AMD64) on the other. I decided to go with my old NT convention
> for grins, and give 50% over physical for swap. But since I have both
> swap partitions available, I have both the 32 and 64 bit installs using
> both swaps, for a nearly 1:1 phys:swap ratio.
> Reason I am asking is because I will be very soon installing a 250Gb
> Western Digital SATA drive. Long story on the old one, but short
> version is it shot craps before I could ever use it. But now since I
> will be getting all this breathing room I will of course be
> reconfiguring my partitioning scheme. So given the opportunity I would
> like to put some method to the madness.
> One consideration, besides size, is location. This question goes beyond
> swap space, too. How does Linux like to have it's partitions metered
> across multiple drives? Should the root and swap be on different
> physical drives or does it matter? If it is better to separate, which
> would benefit most from "the faster drive"? Does it actually help to
> split the swap amongst partitions on differing drives, similar to (yes,
> remotely similar to) how striping speeds up RAID performance?
> While I am asking, I would also be interested in suggestions with regard
> to partitions and placements. I have been running 5Gb roots that include
> my /var and /home. Most of my "media", including music, video, photos,
> and the like I have been keeping on a separate partition that I mount
> under /mnt/share. This way I have access to it from whichever root I
> boot to, as well as making it publicly readable to my family's logins.
> Not much needs to be kept private, and, well, I manage that when need be.
> I think it would be unwise for me to make the /home directories be the
> same between the two installs (32 and 64-bit). But I am intruiged to
> know how far such a notion could be taken. Being able to have
> Thunderbird and my GPG keys available no matter which I boot to would be
> rather convenient. I could spend more time in 64-bit land. Right now I
> must use the 32-bit install for that.
> Lastly, since I don't want to tap you all toooo much all at once, I am
> curious about this whole "chroot" thing. Since I have both 32 and
> 64-bit installs, is there a way to make my 32-bit root BE the chroot
> under 64-bit? That would totally rock! I have zero experience with this
> and am only sort-of understanding how it all works. I would like to,
> for instance, just run 64-bit firefox and have it use 32-bit
> libflashplayer.so. That, of course, being one of the very few things
> keeping me on the 32-bit side 90% of the time when I would much rather
> go 64-bit as much as possible. But I have heard that you can't have a
> 64-bit app call a 32-bit library. Okay. So then 32-bit FF. But then
> that also means all the dependencies for FF and for FlashPlayer, right?
> Well, then, at what point DO the 64 and 32-bit parts commingle? Would
> 32-bit FF run on the 64-bit X session? That, I could see. Or is it
> some "xnest" type set-up? If it dose run on the display, would it talk
> to 64-bit Gnome? What kind of crazy nightmare am I getting myself into
> with this chroot thingy? Am I better off sitting in a corner, beating my
> head against the wall? Maybe I should stop wasting my time on this and
> use it more (!) effectively, writing pleas to Macromedia to get off
> their corporate duffs and spend the, what, hour or two it would (should:
> can't know with closed-source) take to do the damned port.
> Well that's all the time my meter had, and then some. Thanks in advance
> for the time to read me and for any help and advice. And apologies for
> the cross-posting. You know, I have not seen any "forum guides" of any
> sort come down the pike on any of these newsgroups for a few months. So
> which Linux newsgroup is good for what sorts of linuxy things I just
> don't know. I'd "RTFM" on these newsgroups if I knew where to find it.