CHAPTER 40

Virtual Memory Test (vmem)

The vmem test checks virtual memory; that is, it tests the combination of physical memory and the swap partitions of the disk(s).

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Note - This test may not stop immediately after being disabled.

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This test uses the Solaris valloc (page aligned) system call to allocate, write, read, and compare virtual memory. These operations normally cause heavy paging activity on the system and simulates a stressful environment for the operating system. This test also detects ECC parity errors, memory read errors, addressing problems, and displays the corresponding virtual memory addresses on failure.

Handling Swap Space

Running this test puts a significant burden on the operating system, since it uses the majority of swap space available for testing. You should use the swap space reserve option to vmem when non-SunVTS test processes are started after SunVTS testing has started. See Swap Space Requirements in the SunVTS User's Guide for a complete discussion of swap space requirements.

vmem Options

FIGURE 40-1 vmem

TABLE 40-1 vmem

vmem Options	Description
vmem Configuration	The amount of memory listed in the configuration field is equivalent to the sum of the used and available swap space amounts returned by the swap -s command. It indicates the amount of virtual memory found, rounded up to the nearest Kbyte.
Test Amount	An amount can be specified to test the virtual memory, instead of the default. Specifying a number greater than the available memory, can cause vmem or other running tests to fail.
Mode	Two modes are available: - Regular mode tests the amount of memory and is limited by the amount of physical memory available to the system under test. -Page mode tests assign virtual memory one page at a time. Each page is mapped to the temporary file /tmp/vmem.page and is then paged out to storage once test data is written. Next, the temporary page is paged back into memory for a read and compare. When the stress test execution option is selected, vmem test allocates the entire assigned system memory (through valloc), writing from beginning to end. The memory is then read back and compared with the original pattern, one long word at a time.
Reserve	The Reserve option specifies the amount of memory to reserve from being tested by vmem. The reserved space is used for other processes running concurrently with the or SunVTS tests. The Reserve option can be used to reserve memory in addition to the default. This option applies only to a specific instance. Trying to reserve more memory than what is assigned to be tested by this instance will cause the test to fail

vmem Test Modes

This test is only available in the Functional test mode. In this mode, vmem test writes a pattern to an amount of virtual memory specified by the user. Then the data is read back and compared. If there is a miscompare, the data is read again and compared. Whenever there is a miscompare, the virtual address is reported. When there is a miscompare on recomparison, an attempt is made to convert the virtual address to the physical address if the SunVTS diagnostic driver is installed.

vmem Command Line Syntax

/opt/SUNWvts/bin/vmem standard_arguments -o mode=type, reserve=number,
amount=number, bdinfo=number, cerr=number

TABLE 40-2 vmem

Argument	Explanation
mode=type	Specifies which mode of the vmem test you want to run; you can choose between page mode, which tells the write/read memory test to proceed one system memory page at a time, and regular, which valloc's the entire assigned memory which is read and compared, one long word at a time.
reserve=number	Specifies the amount of Mbytes of virtual memory to reserve in addition to the default amount.
amount=number	Specifies the number of Mbytes of memory to be tested instead of the default amount.
bdinfo=number	Provides the board number information for all the CPU/ memory boards in the system. For example, if board 0 and board 5 have memory, then the bdinfo=33 (2**5+2**0).
cerr=number	Specifies the maximum number of contiguous errors to be dumped when a memory error occurs.

vmem Error Messages

TABLE 40-3 vmem

	Error Message	Probable Cause(s)	Recommended Action
6001	setrlimit(RLIMIT_DATA) failed to set to RLIM_INFINITY: <error_message>	Failed to increase the size of test process' heap to 2GB (fatal error)
6002	Test terminated after finding maximum number (<number>) of noncontiguous errors	Fatal error
6003	msync() failed: <error_message>	Failed to synchronize memory with physical storage (fatal error)
6004	Test terminated after finding miscompared data	Test failed (fatal error)
8001	Test completed. Found %d noncontiguous	Suspect swap partition(s) (fatal error)	Consult your authorized Sun service provider.
	miscompare errors	Suspect SCSI controller
		Faulty system software
8002	Increase swap space to allocate at least <number> MB from the process' heap	Failed to increase mem process' heap storage
8003	Attempt to reserve more than what's been assigned	Fatal error	Reduce the "reserve" amount.
8004	valloc(<address>) failed: <error_message>	Fatal error	Increase swap space or reduce the reserve amount.
8005	Open(<file_name>) failed: <error_message>	Failed to open the file <file_name> used in the "page" mode (fatal error)
8006	mmap() virtual address <address> to <file_name> failed: <error_message>	Failed to map a region at the virtual address of the file <file_name> used in the "page" mode (fatal error)

TABLE 40-3 vmem(Continued)

	Error Message	Probable Cause(s)	Recommended Action
8007	munmap(<address>) failed: <error_message>	Failed to unmap a region at the virtual address of the file <file_name> used in the "page" mode (fatal error)
8008	close() failed on <file_name>: <error_message>	Fatal error
8009	Not enough space to store miscompare information	Failed to allocate space to store miscompare data (fatal error)	Increase swap space or reduce the load on the system
8010	swapctl() failed: <error_message>	Failed to obtain the amount of swap space configured in the system (fatal error)