9.4 VM administration

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When you run Linux under z/VM, there are times when you must simulate real processor or hardware functions. Use the following CP commands to simulate these real operator functions. Remember, to use any CP commands, you must precede them with #CP. Refer to z/VM: CP Command and Utility Reference for more details and commands.

9.4.1 VM CP commands

Use the ATTACH command to attach the following:
- Connect a real device (for example, OSA) to your virtual machine
- Expanded Storage to your virtual machine
Note
This is a privileged command.
Use the COUPLE command to connect two virtual channel-to-channel adapters (CTCAs) or a Network Interface Card (NIC) to a Guest LAN.
Use the DEFINE command to:
- Change the memory size of your virtual machine
- Create virtual CTCAs
- Create temporary minidisks
- Create additional virtual CPUs
- Create Guest LANs
Use the DETACH command to detach the following:
- Virtual processors from your virtual machine
- Virtual devices from your virtual machine
- Expanded Storage from your virtual machine
- Virtual message processor and message devices from your virtual machine
- VM LAN segments
Use the DISPLAY command to see data from both real and virtual storage.
Use the IPL command to simulate an Initial Program Load (boot) for your virtual machine. "IPL" and" boot" are synonymous throughout this chapter.
Use the CP TERMINAL HOLD command to control whether CP displays the Holding status when the terminal screen is full.
Use the CP TERMINAL MORE command to change the number of seconds that elapse between the time when CP issues the MORE... state and sounds the terminal alarm before CP clears the screen.
Use the CP TRACE command to monitor events that occur in your virtual machine.
Use the CP VMDUMP command to dump all or selected pages from the virtual machine's storage.

9.4.2 VM Commands

There are various standard VM commands that you can use to display performance information for your system.

Indicate command

The CP command indicate allows you to obtain information about the status of the z/VM guest system, as well as the status of the system resources of z/VM.

If you are a class G user, you can use indicate to display:

Recent contention for system resources. This can be helpful to predict system throughput and response time characteristics that your virtual machine may experience.
Environment characteristics of your virtual machine. This includes machine type, the origin of the system IPLed (loaded) in your virtual machine, and the presence or quantity of system resources available to your virtual machine.
Measurements of resources used by your virtual machine. These measurements are accumulators, which means they are always increasing after the logon of your virtual machine.

If you are a class E user, the indicate command provides all class G functions and the following:

Detailed information on use of, and contention for, system resources. User IDs of virtual machines currently using certain resources can be displayed.
The status of current active virtual machines as determined by the system scheduler and dispatcher.
Environment characteristics of, and measurements of resources used by, any virtual machine logged on.

Example 9-8 shows the output from the indicate command.

Example 9-8: Output of the indicate command

 indicate AVGPROC-008% 02 XSTORE-000000/SEC MIGRATE-0000/SEC MDC READS-000003/SEC WRITES-000001/SEC HIT RATIO-095% STORAGE-036% PAGING-0000/SEC STEAL-000% Q0-00000(00000)                           DORMANT-00042 Q1-00000(00000)           E1-00000(00000) Q2-00000(00000) EXPAN-001 E2-00000(00000) Q3-00006(00000) EXPAN-001 E3-00000(00000) PROC 0000-008%          PROC 0001-009% LIMITED-00000 Ready; T=0.01/0.01 16:27:57

The indicate active command shows the total number of users active in a specified time interval (the default is 60 seconds), and the number of users in the dispatch, eligible, and dormant list that were active in the specified time interval

 indicate active 0023 USERS, 0006 DISP, 0000 ELIG, 0017 DORM Ready; T=0.01/0.01 16:29:50

The indicate user command displays performance-related information for a Linux virtual machine. This command can be issued from the console of a running Linux virtual machine by prefacing the command with the current terminal line end character (normally a # character); for example, #CP indicate user.

Example 9-9 shows the output from the indicate user linuxc command issued from user maint.

Example 9-9: indicate user command

 indicate user linuxc USERID=LINUXC   MACH=XA STOR=392M VIRT=V XSTORE=NONE IPLSYS=DEV 0200 DEVNUM=00051 PAGES: RES=00091285 WS=00088431 LOCK=00002630 RESVD=00000000 NPREF=00000000 PREF=00000000 READS=00000001 WRITES=00000001 XSTORE=000000 READS=000000 WRITES=000000 MIGRATES=000000 CPU 00: CTIME=21:44 VTIME=009:12 TTIME=010:03 IO=044684         RDR=000000 PRT=000000 PCH=000000 USERID=LINUXC   MACH=XA  STOR=392M VIRT=V XSTORE=NONE IPLSYS=DEV NONE DEVNUM=00051 PAGES: RES=00091285 WS=00000000 LOCK=00002630 RESVD=00000000 NPREF=00000000 PREF=00000000 READS=00000001 WRITES=00000001 XSTORE=000000 READS=000000 WRITES=000000 MIGRATES=000000 CPU 01: CTIME=21:44 VTIME=008:31 TTIME=009:22 IO=016957         RDR=000000 PRT=000000 PCH=000000 Ready; T=0.01/0.01 16:24:21

This response gives all data from the user's VMDBK relevant to the user's virtual machine paging activity, resource occupancy, processor usage, and accumulated I/O activity counts since logon. Time and count values are ever-increasing accumulators.

Example 9-10 shows output from the indicate I/O command.

Example 9-10: Output from indicate i/o command

 indicate i/o LINUXB   1518 LINUXB   ---- LINUXC   1519 LINUXC    ---- LINUXA   3A43 TCPIP    ---- RSCS     ---- PVM      ---- Ready; T=0.01/0.01 16:32:43 indicate paging  No users in page wait  Ready; T=0.01/0.01 16:33:52 indicate load AVGPROC-007% 02 XSTORE-000000/SEC MIGRATE-0000/SEC MDC READS-000003/SEC WRITES-000001/SEC HIT RATIO-094% STORAGE-036% PAGING-0001/SEC STEAL-000% Q0-00000(00000)                           DORMANT-00043 Q1-00000(00000)           E1-00000(00000) Q2-00000(00000) EXPAN-001 E2-00000(00000) Q3-00006(00000) EXPAN-001 E3-00000(00000) PROC 0000-007%          PROC 0001-008% LIMITED-00000

VM query commands

You can use the Q DASD and the Q USER commands to display dasd and users, as shown in Example 9-11.

Example 9-11: q dasd & q user output

 Q dasd DASD 1518 CP SYSTEM LX1518   1 DASD 1519 CP SYSTEM LX1519   1 DASD 151A CP SYSTEM LX151A   1 DASD 151B CP SYSTEM LX151B   1 DASD 151C CP SYSTEM LX151C   1 DASD 151D CP SYSTEM LX151D   1 DASD 151E CP SYSTEM LX151E   1 DASD 151F CP SYSTEM LX151F   1 DASD 1558 CP SYSTEM LX1558   1 DASD 1559 CP SYSTEM LX1559   1 DASD 155A CP SYSTEM LX155A   1 DASD 155B CP SYSTEM LX155B   1 q user    46 USERS,     0 DIALED,      0 NET Ready; T=0.01/0.01 16:37:48

You can see whether mdcache is on, as follows:

    q mdcache    Minidisk cache ON for system    Storage MDC min=0M max=2047M, usage=37%, bias=1.00    Xstore MDC min=0M max=2048M, usage=95%, bias=1.00    Ready; T=0.01/0.01 16:40:46

You can display the minidisks that belong to a user ID, as shown in Example 9-12 on page 235.

Example 9-12: q mdisk

 q mdisk userid linuxc 191-310 det TargetID Tdev OwnerID  Odev Minidisk  DEVNO Duplex LINUXC   0191 LINUXC   0191 Regular   No    No LINUXC   019D MAINT    019D Regular   No    No LINUXC   019E MAINT    019E Regular   No    No LINUXC   019F MAINT    019F Regular   No    No LINUXC   0200 LINUXC   0200 Regular   No    No LINUXC   0201 LINUXC   0201 Regular   No    No LINUXC   0202 LINUXC   0202 Regular   No    No LINUXC   0203 LINUXC   0203 Regular   No    No LINUXC   0204 LINUXC   0204 Regular   No    No

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