Saturday, April 20, 2013

Troubleshooting Hard Drive Connectivity

Disk drive connectivity problems on a Solaris 2.x systems can be caused by software, hardware or PROM configuration problems.

Software Problems

New devices may require that the appropriate /dev and /devices files be created. This can be done through use of the drvconfig and disks commands, but it is usually done by performing a boot -r from the ok> prompt.

Once the system is back, the root user should be able to run format and see the disk listed as available. The disk can then be partitioned and labelled with format and have filesystems created with newfs or mkfs, as appropriate.

The presence of the appropriate /dev and /devices files can be verified by running the commands ls -lL /dev/dsk and ls -lL /dev/rdsk and making sure that they are block and character special files respectively, with major numbers depending on the driver used. (See the ls man page if you are not sure what this means.)

Files that can cause problems with hard drive connectivity include:

    /dev/dsk/c#t#d#s# or /dev/rdsk/c#t#d#s# and related /devices files

Problems with the /dev and /devices files can be corrected directly by removing the offending files and recreating them, either directly with mknod and ln -s or indirectly with drvconfig , disks or boot -r (as appropriate).

Hardware Problems

The most common sources of hard drive connectivity problems (once the device files are built) are loose cables and terminators. Check these first before proceeding.

The system SCSI buses can be probed at the ok> prompt. To set this up, perform the following:

    ok> setenv auto-boot? false
    ok> reset
    ok> probe-scsi-all

    (after output)
    ok> setenv auto-boot? true
    (if appropriate)

This will give a hardware mapping of all SCSI devices on the system. If the hard drive in question does not appear, you have either a hardware problem or a PROM search path problem. To check for the PROM search path problem, run the following:

ok> printenv

Look for the pcia-probe-list or sbus-probe-default parameters and make sure that they are set to the default for your system.

Some additional hardware diagnostics are available at the PROM monitor (ok>) prompt. Additional information may come from navigating the PROM device tree at the ok> prompt.

No comments: