On Sun, Aug 5, 2012 at 4:50 AM, Scott Lawrence wrote:

If you want to hibernate, you need at least as much as you have RAM.

I'm not sure this is true. AFAIK, both swsusp and uswsusp try to reduce the hibernation image as much as possible – I think /sys/power/image_size defaults to 1 GB for swsusp. (A large part of RAM is usually used by cache, which can be just freed before hibernating.) -- Mantas Mikulėnas

2012/8/5 gt :

On Sat, Aug 04, 2012 at 08:46:05PM -0500, David C. Rankin wrote:

...

All,

After installing without AIF, I want to update the install wiki to drop a note about swap. It isn't addressed at all. What is the current Arch recommendation regarding swap creation? I.E.: recommended for systems w/less that 1G of RAM, create swap file of what size? (256M?) Even if swap is not recommended, I at least want to drop that note in the basic install. Thanks.

As others on this thread have elaborated, it comes down to the individual's need. I don't think any distro can dictate about the need of a swap or not.

I almost don't use swap as my RAM can handle my needs. But, just in case, I set swap partition to 1,5x my RAM capacity.

On 08/05/2012 12:04 AM, David C. Rankin wrote:

Scott, C, gt, Rafel,

Thank you for all you comments. I'll drop a note in the wiki that captures a brief set of these considerations and the few steps needed to set up a swap if the user desires.

Well, I do not have permission to write to the Install wiki. I think the best way to handle it is this: after this existing note: <quote> Remember to create any stacked block devices like LVM, LUKS, or RAID. Consider also if you will require swap space for your install. swap is needed for suspend-to-disk capability and is required by a few applications to run. More information on swap can be found in the Partitioning link above. </quote> That is simple enough, it raises the issue and refers the user to where he can find additional info to guild him. -- David C. Rankin, J.D.,P.E.

On Sun, Aug 5, 2012 at 3:24 PM, Kevin Chadwick wrote:

...

Thank you for all you comments. I'll drop a note in the wiki that captures a brief set of these considerations and the few steps needed to set up a swap if the user desires.

With 4Gb and even > 32 Gb rams on some systems you may want to note that you can use a small swap for caching and a second swap file for hibernation that can easily be reclaimed. Not sure if the file can be created on demand and if so how not having enough space to hibernate is handled however.

With swsusp (kernel mode), I don't think you /can/ even hibernate to a file. With uswsusp, the s2disk program could be patched to create a file on demand, and it would simply exit before hibernating if not enough space. But still, I'm not sure whether resuming from a file will work, because the pre-resume kernel has to mount the filesystem in order to read from the hiberfile, but the filesystem is already mounted by the hibernated kernel... -- Mantas Mikulėnas