swap never used

lakeatmt · March 15, 2011, 5:43pm

Hi,

serious problem,

I installed opensuse 11.4 on my Dell workstation just as I did for 11.3.

But now, I saw that my 2G swap has never been used, that is very strange, always
0 bytes (0.0 %) of 2.0 GiB

and my system runs quite slowly than before I worked on 11.3

Help pls.

Daniel W

DaaX · March 15, 2011, 5:48pm

Hi,

Can you post the result of this command :

fdisk -l

gogalthorp · March 15, 2011, 5:48pm

Unless you use a lot of apps or a huge one you may never hit swap. How much memory do you have?

What video card/chip do you have and did you install the proprietor drive for it? My Computer on the desktop should tell you what card and driver are running.

caf4926 · March 15, 2011, 6:01pm

I take it you are attributing the seeming slowness to swap not being used.
It seldom is - Though it will depend how much RAM you have on the machine in question.

lakeatmt · March 15, 2011, 6:02pm

daniel@Office:~> sudo /sbin/fdisk -l
root’s password:

Disk /dev/sdb: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x08000000

Device Boot Start End Blocks Id System
/dev/sdb1 63 160649 80293+ de Dell Utility
/dev/sdb2 160650 12755609 6297480 c W95 FAT32 (LBA)
/dev/sdb3 * 12755610 976768064 482006227+ f W95 Ext’d (LBA)
/dev/sdb5 12755673 16964639 2104483+ 82 Linux swap / Solaris
/dev/sdb6 16964703 58910354 20972826 83 Linux
/dev/sdb7 58910418 976768064 458928823+ 83 Linux
daniel@Office:~>

I got 12G physical memory.

I do simulations, I am pretty sure I will and I always use large memories than ordinary people, because I am running computation fluid dynamic simulation, with a large mesh always. sometime it will use physical memory up to 80% of my physical memory. But still I cannot find swap using as I have seen b4 on my 11.3. So I feel confused. Esp When I on my new 11.4 I found switching the tabs is sometime very slow than b4, like in nautilus or gnome terminal…

I use NVIDIA Quadro FX 3800 video card, I follow the step on a page of opensuse , that is “hard way”, just as I did b4 for 11.3 which worked greatly with no problem (I took notes).

SO what’s going wrong …

Thanks so much

Daniel W

DaaX · March 15, 2011, 6:03pm

Wow ! With that RAM, a 2 GB of swap is of no use… Don’t bother…

caf4926 · March 15, 2011, 6:04pm

Show us the output of ‘top’ from your terminal
Maybe something is hogging the CPU

lakeatmt · March 15, 2011, 6:08pm

Really??? I don’t need swap? Are you sure?

Well, I don;t know how to upload a picture here on this forum. But I have already just ended up with a situation that “run up my 12 G completely, and the program crashes”, when I meshing my flow field. And even then no swap was used… Isn’t this a symbol of something going wrong…

daniel@Office:~/OpenFOAM/daniel-1.6-ext/run/BARC/mesh2/m2LESA> top

top - 13:00:21 up 27 min, 4 users, load average: 0.08, 0.68, 0.70
Tasks: 178 total, 1 running, 177 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 20.0%sy, 0.0%ni, 80.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 12033M total, 1240M used, 10793M free, 17M buffers
Swap: 0M total, 0M used, 0M free, 164M cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
10111 daniel 20 0 8732 1220 828 R 143 0.0 0:00.05 top
1 root 20 0 12460 140 0 S 0 0.0 0:02.59 init
2 root 20 0 0 0 0 S 0 0.0 0:00.00 kthreadd
3 root 20 0 0 0 0 S 0 0.0 0:00.03 ksoftirqd/0
6 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/0
7 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/0
8 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/1
9 root 20 0 0 0 0 S 0 0.0 0:00.00 kworker/1:0
10 root 20 0 0 0 0 S 0 0.0 0:00.02 ksoftirqd/1
11 root 20 0 0 0 0 S 0 0.0 0:00.82 kworker/0:1
12 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/1
13 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/2
14 root 20 0 0 0 0 S 0 0.0 0:00.00 kworker/2:0
15 root 20 0 0 0 0 S 0 0.0 0:00.01 ksoftirqd/2
16 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/2
17 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/3
18 root 20 0 0 0 0 S 0 0.0 0:00.00 kworker/3:0
19 root 20 0 0 0 0 S 0 0.0 0:00.01 ksoftirqd/3
20 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/3
21 root 0 -20 0 0 0 S 0 0.0 0:00.00 cpuset
22 root 0 -20 0 0 0 S 0 0.0 0:00.00 khelper
23 root 0 -20 0 0 0 S 0 0.0 0:00.00 netns
24 root 20 0 0 0 0 S 0 0.0 0:00.00 sync_supers
25 root 20 0 0 0 0 S 0 0.0 0:00.00 bdi-default
26 root 0 -20 0 0 0 S 0 0.0 0:00.00 kintegrityd
27 root 0 -20 0 0 0 S 0 0.0 0:00.00 kblockd
28 root 0 -20 0 0 0 S 0 0.0 0:00.00 kacpid
29 root 0 -20 0 0 0 S 0 0.0 0:00.00 kacpi_notify
30 root 0 -20 0 0 0 S 0 0.0 0:00.00 kacpi_hotplug
31 root 20 0 0 0 0 S 0 0.0 0:00.03 kworker/3:1
32 root 20 0 0 0 0 S 0 0.0 0:00.05 kworker/2:1
33 root 20 0 0 0 0 S 0 0.0 0:00.09 kworker/1:1
34 root 0 -20 0 0 0 S 0 0.0 0:00.00 ata_sff
35 root 20 0 0 0 0 S 0 0.0 0:00.00 khubd
36 root 20 0 0 0 0 S 0 0.0 0:00.00 kseriod
37 root 0 -20 0 0 0 S 0 0.0 0:00.00 md
38 root 0 -20 0 0 0 S 0 0.0 0:00.00 kondemand
39 root 20 0 0 0 0 S 0 0.0 0:00.00 khungtaskd
40 root 20 0 0 0 0 S 0 0.0 0:02.44 kswapd0
41 root 25 5 0 0 0 S 0 0.0 0:00.00 ksmd
42 root 20 0 0 0 0 S 0 0.0 0:00.00 fsnotify_mark
43 root 0 -20 0 0 0 S 0 0.0 0:00.00 aio
44 root 0 -20 0 0 0 S 0 0.0 0:00.00 crypto
48 root 20 0 0 0 0 S 0 0.0 0:00.18 scsi_eh_0
49 root 20 0 0 0 0 S 0 0.0 0:00.00 scsi_eh_1
50 root 20 0 0 0 0 S 0 0.0 0:00.00 scsi_eh_2
51 root 20 0 0 0 0 S 0 0.0 0:00.00 scsi_eh_3
52 root 20 0 0 0 0 S 0 0.0 0:00.00 scsi_eh_4
53 root 20 0 0 0 0 S 0 0.0 0:00.00 scsi_eh_5
57 root 20 0 0 0 0 S 0 0.0 0:00.00 kworker/u:4

lakeatmt · March 15, 2011, 6:13pm

processor : 3
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
stepping : 5
cpu MHz : 2526.952
cache size : 8192 KB
physical id : 0
siblings : 4
core id : 3
cpu cores : 4
apicid : 6
initial apicid : 6
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm ida dts tpr_shadow vnmi flexpriority ept vpid
bogomips : 5053.12
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management:

daniel@Office:~> cat /etc/fstab
/dev/disk/by-id/ata-WDC_WD5000AAKS-75V0A0_WD-WCAWF5940489-part5 swap swap defaults 0 0
/dev/disk/by-id/ata-WDC_WD5000AAKS-75V0A0_WD-WCAWF5940489-part6 / ext4 acl,user_xattr 1 1
/dev/disk/by-id/ata-WDC_WD5000AAKS-75V0A0_WD-WCAWF5940489-part7 /home ext4 defaults 1 2
/dev/disk/by-id/ata-WDC_WD5000AAKS-75V0A0_WD-WCAWF5940489-part2 /windows/C vfat users,gid=users,umask=0002,utf8=true 0 0
proc /proc proc defaults 0 0
sysfs /sys sysfs noauto 0 0
debugfs /sys/kernel/debug debugfs noauto 0 0
devpts /dev/pts devpts mode=0620,gid=5 0 0
daniel@Office:~> free
total used free shared buffers cached
Mem: 12322504 1334856 10987648 0 23532 198984
-/+ buffers/cache: 1112340 11210164
Swap: 0 0 0
daniel@Office:~>

gogalthorp · March 15, 2011, 6:18pm

You may or may not need swap but 2 gigs with 12 gig memory is not much use. At 80% usage with 12 gigs you still have more free memory then most desktops. Also use of swap generally does not speed anything up. It generally slows things down since it is a disk operation and is slower then RAM. It is only there to keep from crashing if you do tun out of main memory.

Did you reboot after installing NVIDIA driver? Make sure what is running, look into My Computer.

lakeatmt · March 15, 2011, 6:26pm

At 80% usage with 12 gigs you still have more free memory then most desktops

I just tried a case of “100% usage with 12 gigs”, but still swap was unused… {im a Puzzled Penguin}

Did you reboot after installing NVIDIA driver?

Yes, I did, and even just now, I have rebooted for several time to see what’s going wrong…

Also use of swap generally does not speed anything up

Okay, then I will live with this. (But after rebooted several time, It does faster than early in this morning, but swap unused remains) Thank you for the help.

what happens if you turn off Desktop Effects..

Same, nothing happens. Still unused.

hendersj · March 15, 2011, 6:11pm

On Tue, 15 Mar 2011 17:06:03 +0000, lakeatmt wrote:

> and my system runs quite slowly than before I worked on 11.3

I’d do a root cause analysis on this rather than assuming it’s because
swap isn’t being used. Swap being used generally slows things down
(because it takes time to take memory and write it to disk and take
swapped info and pull it back into memory).

Start by looking in top and see what is consuming the CPU resources in
your system.

Jim

–
Jim Henderson
openSUSE Forums Administrator
Forum Use Terms & Conditions at http://tinyurl.com/openSUSE-T-C

gogalthorp · March 15, 2011, 6:37pm

Desktop effects will wont effect swap usage but it may effect responsiveness. Ok maybe us a little less memory.

On swap issue:
show us output of
cat /etc/fstab

On speed issue:
cat /proc/cpuinfo

lakeatmt · March 15, 2011, 6:42pm

Thanks, but if you follow all the posts in this thread, you will find my point is I am confused that “even I used up all my physical memory, still swap was unused. I think this should not happen in this way, right?”

gogalthorp
Desktop effects will wont effect swap usage but it may effect responsiveness. Ok maybe us a little less memory.

On swap issue:
show us output of
cat /etc/fstab

On speed issue:
cat /proc/cpuinfo

Pls see #10.
I have reported the results.

Thanks

gogalthorp · March 15, 2011, 7:04pm

Sorry missed that post. I only see info for processor 3 I assume you have 4 CPU’s since the count starts at 0

For some reason you show no swap at all but you do have the proper mount command in fstab. I can’t remember ever seeing that before.
type as root
mount all
to see if you get it to mount. Maybe you might see an error message about a problem.

It is a bit confusing dealing with 2 separate issues in the same thread.

DenverD · March 15, 2011, 6:57pm

On 03/15/2011 06:11 PM, Jim Henderson wrote:

> I’d do a root cause analysis on this rather than assuming it’s because
> swap isn’t being used. Swap being used generally slows things down
> (because it takes time to take memory and write it to disk and take
> swapped info and pull it back into memory).
>
> Start by looking in top and see what is consuming the CPU resources in
> your system.

i agree! it sounds like something is amiss in the system…

Linux will normally use a little swap even when the RAM does not
fill…but he has demonstrated he can FILL RPM and crash the system,
without using swap…

something is wrong! and i guess “swap never used” and “my system runs
quite slowly than before I worked on 11.3” are symptoms and not problems…

and, for now, despite others ideas: do NOT remove your swap partition
because it IS of use…

–
DenverD
CAVEAT: http://is.gd/bpoMD
[NNTP posted w/openSUSE 11.3, KDE4.5.5, Thunderbird3.1.8, nVidia
173.14.28 3D, Athlon 64 3000+]
“It is far easier to read, understand and follow the instructions than
to undo the problems caused by not.” DD 23 Jan 11

lakeatmt · March 15, 2011, 7:24pm

i agree! it sounds like something is amiss in the system…

Amiss? What is missing?

symptoms and not problems

Okay, sorry, my english is pretty poor.

and, for now, despite others ideas: do NOT remove your swap partition
because it IS of use…

Certainly, I will not

type as root
mount all

daniel@Office:~> sudo mount all
mount: can’t find all in /etc/fstab or /etc/mtab

gogalthorp · March 15, 2011, 7:48pm

oops wrong parameter

mount -a

See man mount for informations

lakeatmt · March 15, 2011, 7:50pm

mount -a shows nothing.
Nothing happens. Not a single word appears

gogalthorp · March 15, 2011, 7:52pm

See if you report a swap now.