MXX(8) — Pixar Programmer’s Manual

NAME

mxx− Fast-Disk hardware diagnostic utility

SYNOPSIS

mxx [ command [ , command , command ... ] ]

DESCRIPTION

The mxx utility exercises the Pixar Fast-Disk hardware and kernel software. If invoked with arguments on the shell command line, mxx interprets the arguments as commands, executes them, and exits. Multiple commands may be separated by a comma (,) with a space on either side of it, for example:

mxx vo 1 , ft

If mxx is invoked with no command-line arguments, it will prompt the user for commands interactively. Typing ? or h will elicit a display of commands. Typing h followed by a command name will produce a detailed message about that command.

All commands reference a specific File Access Controller (FAC), and usually a specific volume on that controller and a specific partition on that drive. The vo command permits the user to select the active FAC, volume, and partition, which remain in effect until a subsequent vo command. In the absence of this command, mxx assumes the user wishes to refer to partition a of volume 0 on FAC 0.

A list of mxx commands follows. Unless specified otherwise, command arguments are numeric, expressed either as decimal values or hexadecimal values beginning with 0x.

co [ fac ]
Displays information about the configuration of the FAC and all volumes that are attached to it. Fac designates a controller, with numbering beginning at 0; if omitted, mxx displays information about the active FAC. For each of the possible four volumes on the FAC, the following parameters are shown: Present indicates that the FAC has been programmed (via wc) to expect to find the volume; it does not reflect any actual hardware status. Online means that all drives of the volume are present, physically connected to the FAC, and ready to receive commands. Mountable is a user-settable parameter that affects mounted. Mounted implies that the volume is online, mountable, and its volumes contain valid table data; being mounted is a prerequisite for doing I/O to the volume.

de [ register value ]
Deposits value into FAC VMEbus register register. This command can force the FAC out of synchronization with the kernel driver, and must therefore be used with caution. Register is either a hexadecimal number or a mnemonic from the following list:

0x0 config
0x2 intvec
0x4 datadr1
0x6 datadr0
0x8 bcount
0xa dmacontrol
0xc command

dg Displays the logical block numbers of the blocks in the Growth Error Table. Only blocks that fall within the current partition (see vo command) are shown, and the block numbers shown are relative to the beginning of the partition.

dp Displays information about the physical characterstics of the disk hardware in the active volume. See Appendix C (DPT Tables) of the FAC Operation Manual for more details.

et [ tolerance ]
Sets or displays the error tolerance for repetitive commands (ra, tp). Repetitive commands will proceed after an error is detected, until the number of errors reaches the error tolerance value. If tolerance is specified, the error tolerance is set to that number; if it is not, the current error tolerance is displayed and not changed. The default tolerance is 9999999 errors.

ex register
Displays the contents of FAC register register. This command can force the FAC out of synchronization with the kernel driver, and must therefore be used with caution. Register is either a hexadecimal number or a mnemonic from the following list:

0xa dmaisr
0xc status
0xe spreset
0x10 statpoll

ft Tests the MX software driver function repertoire, and performs a basic set of hardware confidence tests on the active volume. These tests involve writing and reading on the active partition, and it is therefore recommended that they be done on the a partition.

fv dsel
Formats the active volume. Dsel is the numeric argument to the hardware Format command. This command will destroy the entire contents of the active volume, and should therefore be used with extreme caution, and preferably by only trained Field Service Engineers.

h [ command ]
Displays helpful information. With no argument, mxx displays a brief summary of all commands. If an argument is given, it is taken as the name of a command, and more detailed information about usage of that command is displayed.

? [ command ]
Has the same function as h.

mo {yes,no}
Sets the "mountable" status of the active volume. A yes argument sets the volume to be mountable; a no argument sets the volume to be not mountable. In normal usage, all volumes physically present on the FAC are left in the "mountable" state.

q Exits mxx and returns to operating system command level.

ra Generates random disk block numbers and reads from them ad infinitum, as an exercise for the controller and disk drive hardware. This command will terminate when the user types Control-C, or when the number of errors exceeds the error tolerance (see et command). This command does not write on the disk, and thus may be used safely at any time.

sf drive cylinder head bytepos bitlen
Specifies media flaw information about the active volume to the FAC. It should be used only under the supervision of Field Service personnel. The arguments are described in the FAC Operation Manual.

tp [ passes [ iosize ] ]
Writes and reads test data patterns on the active partition. Each pass consists of writing all blocks and then reading them all. Passes is the number of passes to perform (defaults to "forever"). Iosize is the size of read/write operations in blocks (defaults to 256, maximum=256). This command will terminate when the specified number of passes have been completed, the user types Control-C, or the number of errors exceeds the error tolerance (see et command).

vo [ volpart ]
Specifies or displays the active volume and partition. Volpart is one or two digits and an optional letter. If the letter is not specified, a is assumed. If volpart is omitted, the current active volume and partition are displayed and not changed.

wc offset value
Writes value into the Controller Configuration Table at byte specified by offset. This table is described in the FAC Operation Manual. This command should be used by Field Service personnel only.

DIAGNOSTICS

Most of the messages issued by mxx are self-explanatory. The following messages deserve more detailed explanation:

Volume vol is not present in hardware configuration

or not present in UNIX kernel configuration
This indicates 1) an improperly configured UNIX kernel, 2) incorrect major or minor device numbers in rmx devices in /dev, or 3) an improprerly configured, improperly installed, or missing FAC VMEbus interface board. Verify that the /dev directory, the UNIX kernel, and the MX hardware are configured according to the installation instructions.

Node /dev/xxx does not exist on this system
The named special device does not exist. This typically indicates that the MAKEDEV installation script was run improperly or not at all.

Cannot open /dev/xxx for read/write, check permissions
Mxx cannot access the named special device. Use ls(1) and chmod(1) to ensure that the user has read and write access to the device.

bnN (read,write) error: explanation
An attempt to read or write from the Fast-Disk at or near block N failed. When this is the result of a hardware failure, it is typically accompanied by MX driver diagnostic messages on the console terminal, which will give the user more details on the exact nature of the failure.

uniqueness test failed bnN exp=E1/E2 act=A1/A2
This message arises from the ft command. During this exercise, mxx writes unique data into the blocks of the area being tested, and then reads back those blocks to verify that the same information is returned. If the read-back data does not match what was originally written, mxx produces this diagnostic message. The actual values of E1, E2, A1, and A2 are not as important as the fact that E1 does not match A1 and/or E2 does not match A2. The causes for this failure can be (but are not limited to) improper cable-length jumper settings on the boards inside the FAC, and faulty cables between the FAC and the host.

CAUTION

Certain commands will have detrimental effects upon customer data stored upon the disk. Before actually executing these commands, mxx will alert the user to the import of what is about to happen and request an explicit confirmation before proceeding.

FILES

/dev/rmxn[abc]

Museum

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