is "pgpgin/s" & "pgpgout/s" total KB paged-in or paged-out?

Hi,

I am UNIX admin and recently started supporting SuSE Linux.
These servers run SAP and one of the folks reported that “SAP solutions manager” is throwing “high page alerts”.

To answer this, I was reviewing the paging statistics captured by SAR and have some fundamental questions.

  1. Are the “pgpgin/s” and “pgpgout/s” reported by “sar -B” command the count of memory pages paged-in and paged-out respectively? if so… I guess we need to multiply that value with 4096 (Linux memory 4K page size) to determine the actual amount of bytes/data paged-in or paged-out right?

uname -r

3.0.101-71-default

getconf PAGESIZE

4096

  1. The man page for sar says that it is the total number of kilobytes paged-in from disk or paged-out to disk. Is the value displayed already in KB’s? (equal to “number of pages” * 4096 / 1024)?

Please suggest/comment.

Thanks.

On 15/12/16 19:34, lnxbum wrote:
[color=blue]

I am UNIX admin and recently started supporting SuSE Linux.
These servers run SAP and one of the folks reported that “SAP solutions
manager” is throwing “high page alerts”.

To answer this, I was reviewing the paging statistics captured by SAR
and have some fundamental questions.

  1. Are the “pgpgin/s” and “pgpgout/s” reported by “sar -B” command the
    count of memory pages paged-in and paged-out respectively? if so… I
    guess we need to multiply that value with 4096 (Linux memory 4K page
    size) to determine the actual amount of bytes/data paged-in or paged-out
    right?

uname -r

3.0.101-71-default

getconf PAGESIZE

4096

  1. The man page for sar says that it is the total number of kilobytes
    paged-in from disk or paged-out to disk. Is the value displayed already
    in KB’s? (equal to “number of pages” * 4096 / 1024)?

Please suggest/comment.[/color]

According to ‘man sar’ pgpgin/s is total number of kilobytes the system
paged in from disk per second and pgpgout/s is total number of kilobytes
the system paged out to disk per second.

However
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/3/html/Introduction_to_System_Administration/s1-memory-rhlspec.html
uses the term “blocks per second”.

In case it makes a difference, which version of SLES are you using?
Please post the output from ‘cat /etc/*release’.

HTH.

Simon
SUSE Knowledge Partner


If you find this post helpful and are logged into the web interface,
please show your appreciation and click on the star below. Thanks.

Hi Simon,

Thanks for the reply.
We are running SuSE11 SP4 and the man page for “sar” says that the value displayed is in blocks/sec, only for old kernels (2.2.x).

cat /etc/SuSE-release

SUSE Linux Enterprise Server 11 (x86_64)
VERSION = 11
PATCHLEVEL = 4

uname -r

3.0.101-71-default

**** excerpts from the “sar” man page ****

   -B     Report paging statistics. Some of the metrics below are available only with post 2.5 kernels. The following values are displayed:

          pgpgin/s
                 Total number of kilobytes the system paged in from disk per second.  Note: With old kernels (2.2.x) this value is a number of blocks per  sec-
                 ond (and not kilobytes).

          pgpgout/s
                 Total number of kilobytes the system paged out to disk per second.  Note: With old kernels (2.2.x) this value is a number of blocks per second
                 (and not kilobytes).

Thanks