Suffering occasional system freezes

[ian_r_h]

Firstly, the terminal command is actually sudo fdisk -l in my previous post.  Sorry for missing the sudo part out.

Secondly, both my other LL laptops (my alternate and my test unit), still running kernel 4.4.0-generic 98 without serious issues, report the same under sudo fdisk -l.  This suggests the configuration was set up at installation ("build time").

This means that anyone (especially a fellow newbie) who follows the prompts from the 64-bit LL 3.6 live-DVD during installation, but checks "encrypt entire hard disk" (and the wipe disk) option may get the same configuration as I have.

Using the terminal commands suggested at

https://www.cyberciti.biz/faq/linux-chec...e-command/

I get the following:-

Code:

ian@linux02:~$ cat /proc/swaps
Filename                Type        Size    Used    Priority
/dev/dm-2                               partition    4108284    0    -1
ian@linux02:~$ swapon -s
Filename                Type        Size    Used    Priority
/dev/dm-2                                  partition    4108284    0    -1
ian@linux02:~$ free -g
              total        used        free      shared  buff/cache   available
Mem:              3           0           2           0           0           2
Swap:             3           0           3
ian@linux02:~$ free -k
              total        used        free      shared  buff/cache   available
Mem:        3960120     1026068     2187332      127540      746720     2555424
Swap:       4108284           0     4108284
ian@linux02:~$ free -m
              total        used        free      shared  buff/cache   available
Mem:           3867        1002        2135         124         729        2495
Swap:          4011           0        4011
ian@linux02:~$ vmstat
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
0  0      0 2186944  32080 714664    0    0    51     8   85  300  4  1 94  1  0
ian@linux02:~$ vmstat 1 5
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
0  0      0 2187068  32088 714992    0    0    50     8   85  300  4  1 94  1  0
0  0      0 2185952  32088 716096    0    0     0     0  355  982  3  2 95  0  0
0  0      0 2186324  32088 716096    0    0     0     0  407 1303  2  4 93  0  0
0  0      0 2186200  32096 716096    0    0     0    12  314  950  2  2 96  1  0
0  0      0 2186324  32096 716096    0    0     0     0  327 1000  3  1 96  0  0

However, one of these three units (I am not sure which), has shown swap being used when I was running task manager previously; complete with noticeable disk activity.  This suggests that at some point in ..98, ..101 and/or ..102 kernels swap had been working.  Also, I have tended to use very large, scripted spreadsheets in a project in recent past in LibreOffice, without any issues.

Again, I hope this helps.

It looks to me like swap is (or had been) working, even if it is not configured as expected(?)  Though I am certainly concerned by the red error message under sudo fdisk -l in my previous post (which is present on all three machines).

Is there any safe way to test the swap file operation?  I.e., to run a test use of the swap space, which will not cause any harm but will report the success or failure of the use of the swap space?