[. . . ] DLTTM TAPE UNIT INSTALLATION SGI® Systems IRIX® 5. 3 and 6. X Installation SGI system must have the appropriate SCSI interface for DLT drive to attached to, i. e. , a SCSI singleended DLT drive can be attached only to a SCSI single-ended interface. The hardware attachment requires the DLT tape peripheral to be attached to the SCSI interface while the system is powered down. [. . . ] This will enable DLT system recognition: For IRIX 5. 3: /* DLT tape drive */ {DECDLT, TPDLT, "<Vendor length>", 7, "<Vendor ID>", "<DLT tape unit>", 0 , 0, {0, 0, 0, 0 }, MTCAN_BSF | MTCAN_BSR | MTCAN_APPEND | MTCAN_SPEOD | MTCAN_CHKRDY | MTCAN_VAR | MTCAN_SETSZ | MTCAN_SILI | MTCAN_SEEK | MTCAN_SYNC | MTCAN_CHTYPEANY, 20, 8*60, 20*60, 5*60, 16384, 64*1024} For IRIX 6. X: /* DLT tape drive */ {DECDLT, TPDLT, "<Vendor length>", 7, "<Vendor ID>", "<DLT tape u nit>", 0 , 0, {0, 0, 0, 0 }, MTCAN_BSF | MTCAN_BSR | MTCAN_APPEND | MTCAN_SPEOD | MTCAN_CHKRDY | MTCAN_VAR | MTCAN_SETSZ | MTCAN_SILI | MTCAN_SEEK | MTCAN_SYNC | MTCAN_CHTYPEANY, 20, 8*60, 20*60, 5*60, 16384, 64*1024, 0 (u_char *)0} Depending on the DLT tape peripheral you are installing, you will need to make substitutions for <Vendor length>, <Vendor ID>, and <DLT tape unit> in the above structure. The following table shows the DLT tape product and the corresponding substitution values: <Vendor length> <DLT tape unit> DLT Tape Product <Vendor ID> DLT1 7 BNCHMARK DLT1 Keep in mind that the Vendor ID entries are case sensitive. Refer to the tpsc_types structure in the /usr/include/sys/tpsc. h file for further information on the above structure entries and to the /usr/include/sys/mtio. h file for further information on the MTCAN flag definitions. 1. Enter the following command to configure the DLT device into the system: /etc/autoconfig 1. After reboot is complete and you have logged in as root, change directory to /dev. Enter the following command to establish the DLT device files: . /MAKEDEV 1. Verify the DLT device files by entering the following command: ls /dev/rmt For a DLT tape peripheral installed with a SCSI ID of 4, the system response should be similar to the following: tps0d4 tps0d4c tps0d4nr tps0d4nrc tps0d4nrnsc tps0d4nrnsv tps0d4nrs tp s0d4nrsv tps0d4nsc tps0d4stat tps0d4sv tps0d4v tps0d4vc tps0d4nrsvc tps0d4nsv tps0d4nrvc tps0d4ns tps0d4s tps0d4sc tps0d4nrnsvc tps0d4nrv tps0d4nsvc tps0d4svc tps0d4nrns tps0d4nrsc 1. Enter the following command to verify the installation: mt -t /dev/rmt/tps0d4 status Note that the device file tps0d4 is for an installed DLT1 with SCSI ID of 4. The system response should be similar to the following: Controller: SCSI Device: BNCHMARK: DLT1 Status: 0x 20262 Drive type: DLT Media : READY, writeable, at BOT DLT Tape Drive Use and IRIX Behavior During periods of non-use of the DLT tape drive there is a danger of unintended overwriting of previously written data. Also, rewinding of DLT tape may occur before the next record is read when the intent is to read the next record at the current tape position. The cause of this behavior is that the IRIX tape driver unloads from system memory after approximately five minutes of non-use of the tape drive. A reload of the driver will occur when a command to access the tape drive is requested. During driver reload, certain initialization tasks occur and one of these tasks is to load a tape cartridge into the drive. For DLT drives, the response to tape load cartridge command when a tape is already loaded is to rewind the tape. [. . . ] Therefore, an installed DLT7 mini-library can not be utilized in random access mode and can only be accessed in sequential mode. Refer to the DLT1/DLT7 Install and Operations Guide product manual for detailed description of these access modes. [. . . ]