Gentoo Archives: gentoo-user

From: Hans-Werner Hilse <hilse@×××.de>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Suspend to swap on a diskless host
Date: Thu, 31 May 2007 11:33:36
In Reply to: Re: [gentoo-user] Suspend to swap on a diskless host by Michal 'vorner' Vaner
1 Hi,
3 On Sun, 27 May 2007 16:21:03 +0200 "Michal 'vorner' Vaner"
4 <vorner@×××.cz> wrote:
6 > First: You need to load the kernel from the swap, in the time it
7 > loads, you have no running kernel (well, there is a little part, but
8 > that one has no clue about network).
10 No, that's not entirely true. Userspace suspend and resume is in the
11 kernel since 2.6.17. See my other post in this thread for a pointer (I
12 think it was So for this way it really happens
13 all in userspace, with a fully working kernel available. When the image
14 is loaded into RAM, the resume utility makes a syscall to have the
15 kernel automatically copy & switch over.
17 See /usr/src/linux/Documentation/power/*suspend* for all the details.
19 > Second: You do not want swap on nfs, since it is terribly slow, buggy,
20 > nfs can allocate memory to transfer data and you get a circular
21 > problem
22 > - to get a memory, you need to get a memory. And, what if your cat
23 > steps on the ethernet cable?
25 Resume aborts, checksum error. But that's it. But true, I wouldn't
26 trust NFS too much, either. But then, there are nbd's (network block
27 devices) which would probably work a treat. But userspace resume from a
28 file on NFS should work reliably, too.
30 You're right, however, regarding the slowlyness. Suspending a 4Gig-RAM
31 machine via NFS is probably a bad idea.
33 > Third: the suspend does not use swap as a swap, but as a part of a
34 > disc.
36 Doesn't matter at all for userspace resume.
38 > You might try suspend to ram, thought. It should work on diskless
39 > machine as well as on any other.
41 ...cough, cough... yeah, /as/ well as on any other. So this probably
42 means: It won't work until you switch off ACPI and resort to APM... But
43 of course, that will depend.
45 -hwh
46 --
47 gentoo-user@g.o mailing list


Subject Author
Re: [gentoo-user] Suspend to swap on a diskless host Michal 'vorner' Vaner <vorner@×××.cz>