My "swap" space seems to have vanished....

[Joel Rees]

On Sat, Mar 19, 2011 at 9:24 PM, DB <Freddog_de at yahoo.co.uk> wrote:
> On 03/18/2011 04:42 PM, users-request at lists.fedoraproject.org wrote:
>> Subject:
>> Re: My "swap" space seems to have vanished....
>> From:
>> "Michael D. Setzer II" <mikes at kuentos.guam.net>
>> Date:
>> Sat, 19 Mar 2011 01:42:33 +1000
>>
>> To:
>> Martin Airs <martin at airs.me.uk>, users at lists.fedoraproject.org
>>
>>
>> On 18 Mar 2011 at 15:34, Martin Airs wrote:
>>
>> From: Martin Airs<martin at airs.me.uk>
>> To:   users at lists.fedoraproject.org
>> Subject:      Re: My "swap" space seems to have vanished....
>> Date sent:    Fri, 18 Mar 2011 15:34:10 +0000
>> Send reply to:        Martin Airs<martin at airs.me.uk>,
>>       Community support for Fedora users<users at lists.fedoraproject.org>
>>       <mailto:users-request at lists.fedoraproject.org?subject=unsubscribe>
>>       <mailto:users-request at lists.fedoraproject.org?subject=subscribe>
>>
>>> >  On Friday 18 Mar 2011 14:46:23 DB wrote:
>>>> >  >     df
>>>> >  >  Filesystem           1K-blocks      Used Available Use% Mounted on
>>>> >  >  /dev/sda2             28833848   5518600  23022388  20% /
>>>> >  >  tmpfs                  1899484      1068   1898416   1% /dev/shm
>>>> >  >  /dev/sda1               474440     50462    399481  12% /boot
>>>> >  >  /dev/sda3            288370940  26611056 247111416  10% /home
>>>> >  >
>>> >
>> Your swap is part of the LVM partitions.
>
> I don't have LVM partitions - at least, I never set any up!!!

That should have been, "either LVM (managed) or (within a) DOS
Extended partition".

The basic (or, "physical") DOS partitioning scheme was invented when
hard disks were relatively small and DOS was really limited anyway,
and it was assumed that it would not form the basis of any serious OS.
(Serious and deliberate lack of foresight on the part of one of the
now richest men in the world.)

So somebody invented a scheme of extending the basic DOS partition
map, but only one partition could be extended that way. I looked back
up in the thread, and that was partition 4 in yours.

Probably, when you were setting up your partitions, gparted told you,
"You can't have more than that without making an extended (DOS
extended, or, "logical") partion." and you did that without thinking
too hard about it.

LVM ("Logical Volume Manager") partitions can also be made in
something the same way, but the prompts that get you there are a
little more noticeable. Also, you can have more than one DOS BASE
partition on a drive be managed by LVM if you want to. (NOT
recommended! although I have done that for multi-booting purposes.)

But, yeah, your swap is not LVM managed. It's within a DOS
extended/logical partition.

> Strangely, just after I sent my original mail, System Monitor suddenly
> decided, all on its own, to add the 2GB swap partition....???????  I
> think I must have a Gremlin somewhere!

The gremlin you are thinking of was probably a stuck event queue, and
calling swapon may have (indirectly?) cleared it.

--
Joel Rees