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    3.11. Quiz

    The following assessment questions help verify your understanding of the topics discussed in this chapter.

    1: When monitoring a system with vmstat, which of the following values under the cpu heading would indicate that the system is probably CPU bound?

    1. The value of wa is greater than 70.

    2. The value of id is greater than 70.

    3. The sum of us and sy is consistently between 99 and 100.

    4. The sum of id and wa is consistently between 99 and 100.

    2: Which of the following commands should be used to show the number of system calls per second that are being executed?

    1. pstat

    2. vmstat

    3. filemon

    4. lockstat

    3: When using vmstat with intervals, which of the following describes the values of the first line of statistics?

    1. Averages since the system boot

    2. Averages since the top of the hour

    3. Averages since the beginning of the day

    4. Averages since the beginning of the month

    4: Using the report from vmstat -s, as shown in the exhibit, which of the following indicates how the paging statistics can be improved?
    Code View: Scroll / Show All
    vmstat -s
   11228009 total address trans.  faults
    1791982 page ins
     419439 page outs
     221142 paging space page ins
     231045 paging space page outs
          0 total reclaims
    3461761 zero filled pages faults
      10630 executable filled pages faults
    3298154 pages examined by clock
         52 revolutions of the clock hand
    1199652 pages freed by the clock
      76372 backtracks
          0 lock misses
          0 free frame waits
          0 extend XPT waits
     254265 pending I/O waits
     823719 start I/Os
     823719 iodones
   43493481 cpu context switches
  140637006 device interrupts
          0 software interrupts
          0 traps
   85003313 syscalls

    1. Add paging space.

    2. Increase CPU power.

    3. Add physical memory.

    4. Reduce the number of system calls.

    5: When monitoring a system using vmstat with an interval, which of the following conclusions should be drawn about the metrics under page pi and page po?

    1. Occasional small numbers are normal.

    2. Any non-zero value of pi or po indicates a RAM shortage.

    3. Any non-zero value of pi or po indicates a paging space shortage.

    4. Large values are normal only on multi-processor systems.

    6: When monitoring a system using /usr/bin/vmstat with an interval, how does the size of the interval affect the page pi and page po metrics?

    1. It should not; the metric is in pages per second.

    2. The larger the interval, the larger the values.

    3. The interval only affects the first data line of output.

    4. The interval only affects the pi column, not the po column.

    7: Which of the following commands will display the total number of pages paged out to paging space since the system was booted?

    1. lsps

    2. iostat

    3. uptime

    4. /usr/bin/vmstat -s

    8: Which of the following tools should be used to analyze memory usage for the whole system at a point in time?

    1. iostat

    2. svmon

    3. netstat

    4. filemon

    9: In order to obtain a list of the top memory users on an AIX Version 4 system, which of the following commands should be used?

    1. pstat

    2. tprof

    3. svmon

    4. filemon

    10: Using the ps -el output, as shown in the exhibit, which of the following conclusions is most appropriate to draw?
    Code View: Scroll / Show All
    								F      S UID PID  PPID C   PRI NI  ADDR  SZ   WCAN   TTY    TIME   CMD
202803 S 0   1    0    0   60  20  1004  528            -   131:33 init
260801 S 0   140  1    0   60  20  4550  208            -   0:00   srcmstr
             6
240801 S 0   169  1    0   60  20  37cd  176  5a6a02    -   0:01   cron
             4                                4
260801 S 0   244  1    0   60  20  5d57  144            -   3:18   portmap
             8
240801 S 0   283  1    0   60  20  34cd   72  5e3439    -   42:42  syncd
             6                                8
 42801 S 0   360  1    0   60  20  50d4  284  cc98      -   0:01   errdemo
             6                                                     n
260801 S 0   525  1    0   60  20  5535  148            -   1:00   syslogd
             5
240801 S 0   554  1    0   59  20  7d9f   60  3f2f8     -   0:00   llbd
             1
240801 S 200 575  7998 0   60  20  a83   180         pts/1  0:00   -ksh
             0    9                                  0
260801 S 0   604  1    0   60  20  1565  468            -   7:53   snmpd
             0
 60801 S 0   629  1    0   60  20  2d6b  224            -   0:00   x_st_mg
             9                                                     r
240801 S 0   650  1406 0   60  20  14e7  184  12d044    -   0:05   qdaemon
             2                                0
 40001 S 0   665  1    0   23      3aae  312  1fca54 hft/0  0:32   userpro
             9                 --                                  g

    1. The snmpd process is running at a fixed priority of 60.

    2. If both the syncd process and the portmap process become runable at the same time, then the syncd process would get scheduled first.

    3. If both the userprog process and the qdaemon process become runable at the same time, then the qdaemon process would get scheduled first.

    4. If both the syslogd process and the llbd process become runable at the same time, then the llbd process would get scheduled first.

    11: Which of the following general operation techniques will best provide a measurable performance improvement of a system?

    1. Attach SCSI devices in ID order.

    2. Perform backups at regular intervals.

    3. Perform regular preventative maintenance of devices with moving parts.

    4. Reschedule the processing to balance the workload.

    12: A developer tried to run a sar report and received the following error: 
    sar:0551-201 cannot open /usr/adm/sa/sa12

    Which of the following procedures should be performed so that the developer can obtain sar reports?

    1. Run bosboot -a -L.

    2. Edit inittab to collect data.

    3. Edit crontab to start collecting data.

    4. Run bosboot -ad /dev/ipldevice and then reboot.

    13: After a migration from an older POWER server to a PowerPC-based server, users complain about decreased performance. Which of the following tools should be used to investigate the performance problem?

    1. netstat

    2. iostat

    3. perfpmr

    4. emstat

    14: To examine the Exhibit, press the Exhibit button. Which of the following conclusions is most appropriate to be drawn from looking at the topas output?

    1. The system is an AIX 5.x and WLM has been installed.

    2. The system is an AIX 4.x and WLM has been installed.

    3. From the command line, topas -d2 -i4 -n2 -p20 -w2 -c2 was run on an AIX 5.x system.

    4. From the command line, topas -d2 -i2 -n2 -p20 -w2 -c2 was run on an AIX 4.x system.

    15: A system administrator wishes to display the five most active processes and the two most active WLM classes but no disk information every 5 seconds. Which of the following commands would accomplish this?

    1. topas -i5 -w0 -p0

    2. topas -i5 -p5 -n0 -d0 -w0

    3. topas -i5 -p5 -d0

    16: Which of the following is true about the page-in and page-out metrics produced by vmstat -s output?

    1. Only file space for page-ins and page-outs is included.

    2. Only client paging for page-ins and page-outs is included.

    3. Only paging space for page-ins and page-outs is included.

    4. Paging to both the file space and paging space is included.

    17: Which of the following is true of vmstat on AIX 5L?

    1. The re column always shows 0.

    2. The b column is always 0 for SMP machines.

    3. The sum of us, sys, id, and wa is always 100.

    4. The sum of r and b is equal to the number of CPUs times two.

    18: When monitoring a system using vmstat with an interval, which of the following conclusions should be drawn about the metrics under page pi and page po?

    1. If pi is twice the value of po then more RAM is needed.

    2. If po is zero and pi is high it does not indicate a memory shortage.

    3. If po is zero and pi is high there is not enough paging on the system.

    4. The pi/po ratio should never be greater than 1 unless both values are 0.

    19: Which of the following options from vmstat indicates that a system is thrashing?

    1. po/fr > 1/h

    2. (fr/sr) > re

    3. (maxperm/minperm) > po

    4. re > 0

    20: What information does the line jfs.10.5.2002 provide in the following example? 
    /proc/9808/object>#ls -l
total 0
dr-xr-xr-x   1 root     printq    Oct 5 10:34 .
dr-xr-xr-x   1 root     system    Oct 5 10:34 ..
-r-xr-xr-x   1 bin      bin       Oct 5 10:34  a.out
-rwxr-xr-x   1 bin      bin       Oct 5 10:34 jfs.10.5.2002

    1. The first two numbers are the major/minor numbers and the 2002 is the inode number for the process.

    2. The first two numbers are date related and the 2002 is the process ID.

    3. The ncheck -s command is run against the jfs.10.5.2002 file to determine what the inode is for the process.

    4. An od -x /proc/9808/object/jfs.10.5.2002 will give me the primary group, user ID, and current size of the running process.

    21: Which of the following commands would a system administrator run to view memory usage by segment?

    1. svmon

    2. tprof

    3. dbx

    4. bootinfo

    22: To get a general idea of memory utilization of a system at the current moment, which of the following commands should be used?

    1. ps aux

    2. lsps -s

    3. bootinfo -r

    4. iostat 5 5

    23: Which of the following performance tools will provide source statement profiling and a summary of all CPU usage?

    1. prof

    2. gprof

    3. tprof

    4. kprof


      

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