[ale] Anyone know if this is true?

[Ron Frazier]

I ONLY ever use suspend to disk or hibernate.  In the past, in Windows, 
the sleep functions have been known to cause data loss in come cases.  I 
don't know the details.  I also don't know if that applies to Linux.  
Also in a sleep state, if the battery dies, and the RAM loses data, it 
can prevent being able to resume without corruption.

Ron

On 10/12/2011 3:57 PM, David Tomaschik wrote:
> On Wed, Oct 12, 2011 at 3:43 PM, Geoffrey Myers
> <lists at serioustechnology.com>  wrote:
>    
>> Damon L. Chesser wrote:
>>      
>>> On Wed, 2011-10-12 at 15:13 -0400, Geoffrey Myers wrote:
>>>        
>>>> 'Just so you all know, when determining how much space to assign to
>>>> swap: Swap isn't just used for paging or virtual memory management; swap
>>>> is also used by power management for suspend-to-disk (hibernation). '
>>>>
>>>> I seriously don't know, so I'm asking.
>>>>          
>>> Yes, it is true.  If you have 4GB of RAM, you need at least 4GB in order
>>> to hibernate and suspend to disk.
>>>        
>> So if you have 16GB memory, you must have 16GB of swap?  Seems a bit
>> inefficient.  I would assume you are rarely using 16GB.  Why not just
>> write what is being used?
>>      
> No, you don't need 16GB of swap.  Technically, all you need is space
> for the parts of data that are not already disk-backed.  Basically,
> it's the resident size of all running applications plus any "dirty"
> cache pages and active buffers.  (And all memory pages actively in use
> by the kernel.)
>
> There's even more to it than that, but that's close enough unless you
> want to talk about kernel development.
>
> Though, does anyone still use suspend to disk?
>
>    
>>> All the contents of RAM are written to swap and that is used to come
>>> back up in the "saved" state.  This is also why, if you have encrypted
>>> partitions, you need to have encrypted swap as well.
>>>
>>> What I am confused about are the two names used to suspend:  the mode
>>> where you use zero power and everything is written to disk and the mode
>>> where you just shutdown the drives, screen, and only use RAM.
>>>        
>
>
>
>    

-- 

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Ron Frazier

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