confused about cpu idle time please advise???

[Scunningham99]

Hi

Looking at following stats ... they are totally inconsistent!

How come iostat shows cpu idle time at 0 and vmstat does not.

Also when I do a top is shows 0.0% idle, any IDEAS??

last pid: 26549; load averages: 1.55, 1.62, 1.66 18:48:32
131 processes: 129 sleeping, 2 on cpu
CPU states: 0.0% idle, 25.6% user, 1.4% kernel, 73.0% iowait, 0.0% swap
Memory: 8192M real, 3378M free, 8193M swap free

PID USERNAME THR PRI NICE SIZE RES STATE TIME CPU COMMAND
15847 oratest 11 0 0 1031M 995M cpu5 19.1H 24.98% oracle
3507 oratest 11 58 0 1035M 1002M sleep 224.5H 7.43% oracle
26541 root 1 50 0 2088K 1472K cpu4 0:00 0.32% top
16832 oracle 11 58 0 535M 505M sleep 6:58 0.23% oracle
4924 root 5 58 0 75M 59M sleep 17:52 0.14% sp_opst
16825 oracle 11 18 0 1029M 999M sleep 8:32 0.12% oracle
25983 daemon 1 58 0 529M 495M sleep 0:01 0.09% oracle
16814 root 5 58 0 27M 14M sleep 0:48 0.09% fgaOraAgent92
25668 daemon 1 58 0 529M 495M sleep 0:03 0.09% oracle
22621 oracle 1 58 0 1026M 991M sleep 0:09 0.06% oracle
25767 daemon 1 58 0 529M 495M sleep 0:02 0.06% oracle
26528 root 1 42 0 336K 232K sleep 0:00 0.03% sh
16528 oracle 13 58 0 536M 488M sleep 9:50 0.02% oracle
14170 root 1 58 0 44M 34M sleep 6:59 0.02% sp_mport
16795 root 5 58 0 27M 15M sleep 1:03 0.02% fgaOraAgent92


euratlsunx06# iostat 5 5
tty hsx1 hsx202 hsx1207 hsx1408 cpu
tin tout kps tps serv kps tps serv kps tps serv kps tps serv us sy wt id
0 1 248 12 3 0 0 0 0 0 0 0 0 0 14 3 83 0
0 45 176 16 3 0 0 0 0 0 0 0 0 0 38 11 51 0
0 15 94 10 1 0 0 0 0 0 0 0 0 0 38 11 51 0
0 15 93 10 2 0 0 0 0 0 0 0 0 0 38 11 51 0
0 15 118 14 2 0 0 0 0 0 0 0 0 0 38 11 51 0
euratlsunx06# vmstat 5 5
procs memory page disk faults cpu
r b w swap free re mf pi po fr de sr hx hx hx hx in sy cs us sy id
0 139 0 12861416 4579344 969 75 1 1 1 0 0 12 0 0 0 1490 1629 542 14 3 83
0 101592566 0 11744528 3459048 13 38 0 0 0 0 0 11 0 0 0 1513 1236 498 24 3 73
0 101592588 0 11744584 3459104 3 39 0 0 0 0 0 6 0 0 0 1492 1070 415 25 1 74
0 101592600 0 11744584 3459104 6 39 0 0 0 0 0 6 0 0 0 1494 1152 433 25 1 74
0 101592605 0 11744528 3459056 10 39 0 0 0 0 0 16 0 0 0 1530 1495 525 26 1 72
euratlsunx06# iostat -xnp
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
4.7 7.3 71.0 177.4 0.0 0.0 0.0 2.5 0 2 hsx1
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 hsx202
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 hsx1207
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 hsx1408
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c0t6d0
0.4 1.9 9.1 23.4 0.0 0.0 0.0 9.4 0 2 ssd0
0.4 1.9 9.1 23.4 0.0 0.0 0.0 9.4 0 2 ssd0,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd0,h
0.4 1.7 9.1 21.5 0.0 0.0 0.0 8.8 0 2 ssd1
0.4 1.7 9.1 21.5 0.0 0.0 0.0 8.8 0 2 ssd1,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd1,h
0.4 1.9 9.1 23.4 0.0 0.0 0.0 9.5 0 2 ssd2
0.4 1.9 9.1 23.4 0.0 0.0 0.0 9.5 0 2 ssd2,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd2,h
0.4 1.8 9.1 21.8 0.0 0.0 0.0 9.1 0 2 ssd3
0.4 1.8 9.1 21.8 0.0 0.0 0.0 9.1 0 2 ssd3,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd3,h
0.4 1.7 9.1 21.2 0.0 0.0 0.0 7.8 0 1 ssd4
0.4 1.7 9.1 21.2 0.0 0.0 0.0 7.8 0 1 ssd4,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd4,h
0.4 1.6 9.1 20.8 0.0 0.0 0.0 7.6 0 1 ssd5
0.4 1.6 9.1 20.8 0.0 0.0 0.0 7.6 0 1 ssd5,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd5,h
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 0 0 ssd6
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd6,a
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 0 0 ssd6,c
0.4 1.8 9.1 21.8 0.0 0.0 0.0 9.1 0 2 ssd7
0.4 1.8 9.1 21.8 0.0 0.0 0.0 9.1 0 2 ssd7,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd7,h
0.0 0.2 0.6 2.3 0.0 0.0 10.6 31.1 0 0 ssd8
0.0 0.2 0.1 1.1 0.0 0.0 9.1 31.1 0 0 ssd8,a
0.0 0.1 0.0 0.5 0.0 0.0 3.3 25.9 0 0 ssd8,b
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.5 0 0 ssd8,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.6 0 0 ssd8,d
0.0 0.0 0.1 0.1 0.0 0.0 10.0 29.0 0 0 ssd8,f
0.0 0.0 0.1 0.2 0.0 0.0 30.3 41.2 0 0 ssd8,g
0.0 0.0 0.3 0.5 0.0 0.0 10.8 23.7 0 0 ssd8,h
0.4 1.6 9.1 20.8 0.0 0.0 0.0 8.8 0 1 ssd9
0.4 1.6 9.1 20.8 0.0 0.0 0.0 8.8 0 1 ssd9,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd9,h
0.4 1.7 9.1 21.5 0.0 0.0 0.0 8.8 0 2 ssd10
0.4 1.7 9.1 21.5 0.0 0.0 0.0 8.8 0 2 ssd10,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd10,h
0.4 1.7 9.1 21.2 0.0 0.0 0.0 9.3 0 2 ssd11
0.4 1.7 9.1 21.2 0.0 0.0 0.0 9.3 0 2 ssd11,c
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 ssd11,h
4.7 7.3 71.0 177.4 0.0 0.0 0.0 2.6 0 2 c2t0d2
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c2t0d2s0
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c2t0d2s1
4.7 7.3 71.0 177.4 0.0 0.0 0.0 2.6 0 2 c2t0d2s2
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c2t0d2s6
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 0 0 c2t0d2s7
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.2 0 0 euratlsunx06:vold()

Sy UK

 

[Annihilannic]

iostat breaks CPU usage down into four categories, user (us), system (sy), waiting for I/O (wt) and idle (id).

vmstat only uses user, system and idle, considering "waiting for I/O" to be part of "idle" time because the CPUs are effectively idle while they're waiting for I/O.

top takes a similar view to iostat.

Annihilannic.

 

[Scunningham99]

thanks for your response. so we agree that this is not good the stats from "wt" in iostat?



Sy UK

 

[Annihilannic]

Not necessarily, performance is one of those holistic problems for which there is never really an ideal... frequently when a system is perfectly tuned I/O ends up being the bottleneck. If you improve the I/O subsystem then the bottleneck will just shift somewhere else. But in your case I'd certainly examine it and make sure all your buffering is working as expected, etc. The true measure of performance is the end user... is the system too slow? Taking too long to run their jobs?

Annihilannic.