LTO

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LTO

Linear Tape-Open (or LTO) is a magnetic tape data storage technology originally developed in the late 1990s as an open standards alternative to the proprietary magnetic tape formats that were available at the time. Hewlett-Packard, IBM and Certance (at that time the removable storage systems division of Seagate Technology and now Quantum Corp.) initiated the LTO Consortium, which directs development and manages licensing and certification of media and mechanism manufacturers. The standard form-factor of LTO technology goes by the name Ultrium, the original version of which was released in 2000 and could hold 100 GB of data in a single cartridge. The most recent version was released in 2010 and can hold 1.5 TB in the same size cartridge. Since 2002, LTO has been the best selling "super tape" format and is widely used with small and large computer systems, specially for backup.


Manual is a available here

Example Kernel Configuration file

 { DATTAPE, TPDAT, 2, 7, "HP", "Ultrium", /*LTO-1*/, 0, 0, {0},
    MTCAN_BSF|MTCAN_BSR|MTCAN_APPEND|MTCAN_COMPRESS|MTCAN_PREV|
      MTCAN_SYNC|MTCAN_SPEOD|MTCAN_CHKRDY|MTCAN_VAR|MTCAN_SETSZ|
      MTCAN_SILI|MTCAN_SEEK|MTCAN_CHTYPEANY,
    /* minimum delay on i/o is 4 minutes, because when a retry is
     * performed, the drive retries a number of times, and then
     * rewinds to BOT, repositions, and tries again. */
    40, 5*60, 20*60, 20*60, 3*3600, 512, 512*512,
    tpsc_default_dens_count, tpsc_default_hwg_dens_names,
    tpsc_default_alias_dens_names, 
    {0}, 0, 0, 0,
    0, (u_char *)0 },


In a follow up to videobrat's original post, LoWeN mentions that an additional piece of <licensed> IRIX software is required to allow the use of tape drives larger than a DLT IV <LoWeN is a person with a respectible amount of IRIX knowledge>. That addition software mentioned by LoWeN is an asynchronous personality daemon, or APD. Here's a forum post by videobrat where he describes problems with a Quantum LTO-3 drive used without APD - and a follow up post where he mentions that an HP LTO-3 drive he got as a replacement for the Quantum LTO-3 worked without APD.

The best practice may be to test a non-APD backup *before* a critical system back up is done.

There's not much in TechPubs on APD beyond some <similar> customer letters <scroll down to see the list>, and an indirect mention in the IRIX 6.5.30 Release Announcement that certain drives <that need the APD software> would appear in "mt status" as an "Async Personality Device".

The IRIX asynchronous personality daemon *might* provide for faster read/write performance, but was also intended as a marketing device to guide customers contemplating the purchase of a tape drive back to SGI. One source that might shed additional light on the subject is Sony's Unix Configuration Guide v2.24. In that manual Sony recommends using APD v2.7 for their AIT-3 and SAIT-1 drives, but also provides a IRIX kernel configuration file to allow "testing without APD" <perhaps Sony's way of backdooring APD when Sony's potential customers balked at having to purchase an APD license just to test Sony's drives> . Sony's inclusion of a 'test' kernel driver at least suggests some drives will function without the addition of the APD software, and might hint that not using APD doesn't result in a performance hit - it would hardly behoove Sony to provide a method to test their drives that provide degraded performance. In either case, the ability to use any of the drives listed below could still offer backup capacities greater than DDS4 or DLT IV.


Here are a few more kernel configuration files for tape drives that are larger/newer than those included in with IRIX. In an attempt to consolidate, the last four were recopied from videobrat's 2005 nekochan post.

HP Ultrium 1 / LTO-1

       /* HP Ultrium 1 / LTO-1 */       
        { DATTAPE, TPDAT, 2, 7, "HP", "Ultrium", /*LTO-1*/, 0, 0, {0},
          MTCAN_BSF|MTCAN_BSR|MTCAN_APPEND|MTCAN_COMPRESS|MTCAN_PREV|
            MTCAN_SYNC|MTCAN_SPEOD|MTCAN_CHKRDY|MTCAN_VAR|MTCAN_SETSZ|
            MTCAN_SILI|MTCAN_SEEK|MTCAN_CHTYPEANY,
          /* minimum delay on i/o is 4 minutes, because when a retry is
           * performed, the drive retries a number of times, and then
           * rewinds to BOT, repositions, and tries again. */
          40, 5*60, 20*60, 20*60, 3*3600, 512, 512*512,
          tpsc_default_dens_count, tpsc_default_hwg_dens_names,
            tpsc_default_alias_dens_names,
         {0}, 0, 0, 0,
         0, (u_char *)0 },

IBM LTO2

   /* IBM LTO-2 / Ultrium-TD2 */
   { DATTAPE, TPDAT, 3, 11, "IBM", "ULTRIUM-TD2", 0, 0, {0},
     MTCAN_BSF|MTCAN_BSR|MTCAN_APPEND|MTCAN_SETMK|
       MTCAN_PREV|MTCAN_SYNC|MTCAN_SPEOD|MTCAN_CHKRDY|MTC AN_VAR|
       MTCAN_SETSZ|MTCAN_SILI|MTCAN_SEEK|MTCAN_COMPRESS,
     40, 5*60, 10*60, 10*60, 3*3600, 512, 256*512,
     tpsc_default_dens_count, tpsc_default_hwg_dens_names,
       tpsc_default_alias_dens_names,
     {0}, 0, 0, 0,
     0, (u_char *)0 },

IBM LTO3

   /* IBM LTO-3 / Ultrium-TD3 */
    { DATTAPE, TPDAT, 3, 11, "IBM", "ULTRIUM-TD3", 0, 0, {0},
      MTCAN_BSF|MTCAN_BSR|MTCAN_APPEND|MTCAN_SETMK|
        MTCAN_PREV|MTCAN_SYNC|MTCAN_SPEOD|MTCAN_CHKRDY|MTC AN_VAR|
        MTCAN_SETSZ|MTCAN_SILI|MTCAN_SEEK|MTCAN_COMPRESS,
      40, 5*60, 10*60, 10*60, 3*3600, 512, 256*512,
      tpsc_default_dens_count, tpsc_default_hwg_dens_names,
        tpsc_default_alias_dens_names,
      {0}, 0, 0, 0,
      0, (u_char *)0 },

Quantum SuperDLT-1

   /* Quantum SuperDLT-1 */
    { DECDLT, TPDLT, 7, 9, "QUANTUM", "SuperDLT1", 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 | MTCAN_COMPRESS,
      20, 8*60, 20*60, 5*60, 3*3600, 4096, 64*1024,
      tpsc_default_dens_count, tpsc_default_hwg_dens_names,
          tpsc_default_alias_dens_names,
           {0}, 0, 0, 0, 
      0, (u_char *)0 },

HP Ultrium-3/LTO-3 <originally provided byvideobrat in this nekochan post>

       /* HP LTO3 / Ultrium 3 */
        { DATTAPE, TPDAT, 2, 9, "HP", "Ultrium 3", 0, 0, {0},
          MTCAN_BSF|MTCAN_BSR|MTCAN_APPEND|MTCAN_SETMK|MTCAN_PART|MTCAN_PREV|
            MTCAN_SYNC|MTCAN_SPEOD|MTCAN_CHKRDY|MTCAN_VAR|MTCAN_SETSZ|
            MTCAN_SILI|MTCAN_AUDIO|MTCAN_SEEK|MTCAN_CHTYPEANY|MTCAN_COMPRESS,
          40, 5*60, 20*60, 20*60, 3*3600, 512, 512*512,
          tpsc_default_dens_count, tpsc_default_hwg_dens_names,
            tpsc_default_alias_dens_names,
          {0}, 0, 0, 0,
          0, (u_char *)0 },

The following were also provided by videobrat <in this original post>: Quantum/DEC SDLT 220

       /* DEC THZxx SuperDLT1 drive */
       { DECDLT, TPDLT, 7, 9, "QUANTUM", "SDLT220", 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 | MTCAN_COMPRESS | MTCAN_SETDEN,
        20, 8*60, 20*60, 5*60, 3*3600, 4096, 64*1024,
        tpsc_default_dens_count, tpsc_default_hwg_dens_names,
        tpsc_default_alias_dens_names,
        {0}, 0, 0, 0,
        0, (u_char *)0 },

Quantum/DEC SDLT 320

       /* DEC THZxx SuperDLT1 drive */
       { DECDLT, TPDLT, 7, 7, "QUANTUM", "SDLT320", 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 | MTCAN_COMPRESS | MTCAN_SETDEN,
        20, 8*60, 20*60, 5*60, 3*3600, 4096, 64*1024,
        tpsc_default_dens_count, tpsc_default_hwg_dens_names,
        tpsc_default_alias_dens_names,
        {0}, 0, 0, 0,
        0, (u_char *)0 },

Quantum SDLT 600

       /* Quantum SDLT600 drive */
       { DECDLT, TPDLT, 0, 7, "", "SDLT600", 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 | MTCAN_COMPRESS | MTCAN_SETDEN,
        20, 8*60, 20*60, 5*60, 3*3600, 16384, 64*1024,
        tpsc_default_dens_count, tpsc_default_hwg_dens_names, tpsc_default_alias_dens_names,
        {0}, 0, 0, 0,
        0, (u_char *)0 },

Sony DTF-2

        /* SONY GY-8240 DTF2 drive */
        { SONYGY, TPGY2120, 4, 7, "SONY", "GY-8240", 0, 0, {0, 0, 0, 0},
           MTCAN_BSF | MTCAN_BSR | MTCANT_RET | MTCAN_CHKRDY | MTCAN_PREV |
            MTCAN_SEEK | MTCAN_APPEND | MTCAN_SILI | MTCAN_VAR | MTCAN_SETSZ |
             MTCAN_CHTYPEANY | MTCAN_COMPRESS,
              20, 100*60, 10*60, 9*60, 9*60, 16384, 256*1024,
          tpsc_default_dens_count, tpsc_default_hwg_dens_names, tpsc_default_alias_dens_names,
          {0}, 0, 0, 0,
          0, (u_char *)0 },

See Also