Re: Off-Topic : Basic Critical O.S. Values that Trigger Problem Alert

Hi Vivek,

This will indeed show the collisions on your networks. The numbers are counts since the last reboot.

lo0 is the loopback device (i.e. no hardware, just using the TCP stack to talk from a machine to itself).

hme0 is a 100BaseT ethernet device and looks to be your main interface. This could show collisions if there were any. There aren't.

Ipkts and Opkts are input and output packets respectively. For his rule of thumb it probably is just Opkts, but you'd have to ask him.

I'd actually consider 10% collisions to be very high and would look carefully at the network to see if there were problems.

You may also want to use netstat dynamically to get numbers in some time period instead of just since boot.

Dave Miller

>X-Unix-From: VIVEK_SHARMA_at_infosys.com Thu Aug 1 06:35:59 2002
>Date: Thu, 01 Aug 2002 03:48:19 -0800
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>X-Comment: Oracle RDBMS Community Forum
>X-Sender: "VIVEK_SHARMA" <VIVEK_SHARMA_at_infosys.com>
>From: "VIVEK_SHARMA" <VIVEK_SHARMA_at_infosys.com>
>Subject: Off-Topic : Basic Critical O.S. Values that Trigger Problem Alert
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>
>Hi
>
>Kevin wrote "Network (netstat): collisions < 10% of "packets transmitted" (0%
in "switched"
>environment)"
>
>
>Following is an Output on Solaris :-
>
>netstat -i
>Name Mtu Net/Dest Address Ipkts Ierrs Opkts Oerrs Collis
Queue
>lo0 8232 loopback localhost 14055860 0 14055860 0 0
 0
>hme0 1500 sundb sundb 1169701421 7 940887777 0 0
 0
>
>Qs 1 Am i using the Correct netstat to Check Collisions ?
>Qs 2 Is Collis Unit in % ?
>Qs 3 Is "packets transmitted" = (Ipkts + Opkts) ?
>Qs 4 How do i know what is my Environment i.e. "swiched" or not ?
>
>Thanks
>
>
>-----Original Message-----
>Sent: Wednesday, July 31, 2002 12:10 AM
>To: VIVEK_SHARMA
>
>
>
>
>Greetings,
>
> Here's some simple "rules of thumb" that may or may not be appropriate
>for every situation:
>
>CPU utilization (sar -u or vmstat / mpstat): user <= 60%, sys <= 30%, wait
>I/O = 0%, idle >= 10%
>Memory (sar -g or vmstat): scan rate = 0 if running Solaris 8 or 9, scan
>rate < 273 pages / second on Solaris 7 and earlier if priority paging is
>not enabled (if priority paging is enabled, then scan rate can't be used to
>determine if there's a memory bottleneck)
>Disk (sar -d or iostat): average service time < 30 ms and busy < 25%
>Network (netstat): collisions < 10% of packets transmitted (0% in switched
>environment)
>
> For more detailed information, I'd highly recommend picking up a copy
>of "System Performance Tuning" (2nd edition) by Gian-Paolo D. Musumeci and
>Mike Loukides. HTH...
>
>Kevin Buterbaugh
>LifeWay
>
>"Anyone can build a fast CPU. The trick is to build a fast system." -
>Seymour Cray
>
>
>Sent by: sunmanagers-admin_at_sunmanagers.org
>
>
>To: <oracledba_at_lazydba.com>, <ORACLE-L_at_fatcity.com>,
> <sunmanagers_at_sunmanagers.org>
>cc:
>
>
>
>Hi
>
>We are Trying to make a General Document to be forwarded to Customers which
>should allow them to know when they are performing far below normal
>
>At the Operating System Level we are trying to Identify Practical
>Critical Values which when below respective Threshold Limits which
>would give the alert about a potential problem .
>
>We are Looking for these in Areas of :-
>
>1) Network Thruput
>2) Memory Utilization
>3) Swap Utilization
>4) IO Utilization
>
>Would apreciate actual Commands used (preferably those Generic across
>different O.S.) & respective Critical Threshold Limit Values for the Above
>
>EXAMPLE For Network thruput Between APPLICATION Server machine & Database
>Server Machine
>what , by experience , are the parameters & their respective Minimum
>threshold Values which would let us know that there is a Severe problem
>therein ?
>
>NOTE - We have generally been measuring this by Manually ftping a Big
>File , about 100MB , between APP & DB Server machines , noting the thruput
>Displayed in (kbytes/s) on Completion & Converting this Value to Mega Bits
>/
>Second
>(i.e. MBPS) . If this Value is Less than 40MBPS for a 100 MBPS Cable we
>know there is a PRoblem with Network Bandwidth.
>
>Miscellaneous - Some Threshold Limits known to us :-
>
>Command - vmstat 5 3
>Virtual Memory Statistics: (pagesize = 8192)
> procs memory pages intr
>cpu
> r w u act free wire fault cow zero react pin pout in sy cs us
>sy
>id
> 3 1K 34 266K 84K 32K 811M 132M 339M 635 193M 0 188 28K 1K 16
>7
>77
> 3 1K 33 267K 84K 32K 410 71 151 0 131 0 494 2K 4K 4 2
>93
> 3 1K 36 269K 82K 32K 5459 1720 807 0 3016 0 471 3K 4K 37
>5
>58
>
>
>1) Utilization of CPU due to Operating System (Internal) Operations (%sy)
>Exceeding Utilization due to user Applications (%us)
>
>2) Average Wait of CPU for IO to Complete (%wio) Greater than (>) 30 % [
>From
>sar Command ]
>
>3) Utilization of CPU due to Operating System (Internal) Operations (%sy) >
>30
>%
>
>4) CPU Utilization - If Total CPU Utilization Consistently Near 0%
>Idle Or further Coupled with any of the following :-
> a)Abnormally High Wait for IO ( > 30 %) [ From sar Command ]
> b)Abnormally High Operating System CPU Utilization ( > 30 %)
> c)Abnormally High Run Queue ["r" > (3 * Number of CPUs)]
>
>THANKS
>--
>Please see the official ORACLE-L FAQ: http://www.orafaq.com
>--
>Author: VIVEK_SHARMA
> INET: VIVEK_SHARMA_at_infosys.com
>
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-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: David Miller
  INET: dm32840_at_bachelor.West.Sun.COM

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