test

System Administration Guide: Advanced Administration

ProcedureHow to Check Page-In Activity (sar -p)

  1. Use the sar -p command to report page-in activity, which includes protection and translation faults.


    $ sar -p
00:00:00  atch/s  pgin/s ppgin/s  pflt/s  vflt/s slock/s
01:00:00    0.07    0.00    0.00    0.21    0.39    0.00
Example 13–11 Checking Page-In Activity (sar -p)

The following example shows output from the sar -p command. 


$ sar -p

SunOS balmyday 5.10 s10_51 sun4u    03/18/2004

00:00:04  atch/s  pgin/s ppgin/s  pflt/s  vflt/s slock/s
01:00:00    0.09    0.00    0.00    0.78    2.02    0.00
02:00:01    0.08    0.00    0.00    0.78    2.02    0.00
03:00:00    0.09    0.00    0.00    0.81    2.07    0.00
04:00:00    0.11    0.01    0.01    0.86    2.18    0.00
05:00:00    0.08    0.00    0.00    0.78    2.02    0.00
06:00:00    0.09    0.00    0.00    0.78    2.02    0.00
07:00:00    0.08    0.00    0.00    0.78    2.02    0.00
08:00:00    0.09    0.00    0.00    0.78    2.02    0.00
08:20:00    0.11    0.00    0.00    0.87    2.24    0.00
08:40:01    0.13    0.00    0.00    0.90    2.29    0.00
09:00:00    0.11    0.00    0.00    0.88    2.24    0.00
09:20:00    0.10    0.00    0.00    0.88    2.24    0.00
09:40:00    2.91    1.80    2.38    4.61   17.62    0.00
10:00:00    2.74    2.03    3.08    8.17   21.76    0.00
10:20:00    0.16    0.04    0.04    1.92    2.96    0.00
10:40:00    2.10    2.50    3.42    6.62   16.51    0.00
11:00:00    3.36    0.87    1.35    3.92   15.12    0.00

Average     0.42    0.22    0.31    1.45    4.00    0.00

The following table describes the reported statistics from the -p option.

Field Name 

Description 

atch/s

The number of page faults, per second, that are satisfied by reclaiming a page currently in memory (attaches per second). Instances include reclaiming an invalid page from the free list and sharing a page of text that is currently being used by another process. An example is two or more processes that are accessing the same program text. 

pgin/s

The number of times, per second, that file systems receive page-in requests. 

ppgin/s

The number of pages paged in, per second. A single page-in request, such as a soft-lock request (see slock/s) or a large block size, might involve paging-in multiple pages.

pflt/s

The number of page faults from protection errors. Instances of protection faults indicate illegal access to a page and “copy-on-writes.” Generally, this number consists primarily of “copy-on-writes.” 

vflt/s

The number of address translation page faults, per second. These faults are known as validity faults. Validity faults occur when a valid process table entry does not exist for a given virtual address. 

slock/s

The number of faults, per second, caused by software lock requests that require physical I/O. An example of the occurrence of a soft-lock request is the transfer of data from a disk to memory. The system locks the page that is to receive the data so that the page cannot be claimed and used by another process.