db2 tsm backup fails with rc–50(1)

2015-01-05-19.21.54.477532+000 E8484227A347       LEVEL: Error
PID     : 10027058             TID  : 1           PROC : db2vend
INSTANCE: ldapdb2              NODE : 000
EDUID   : 1
FUNCTION: DB2 UDB, database utilities, sqluvint, probe:405
DATA #1 : TSM RC, PD_DB2_TYPE_TSM_RC, 4 bytes
TSM RC=0xFFFFFFCE=-50 -- see TSM API Reference for meaning.

2015-01-05-19.21.54.478641+000 E8484575A862       LEVEL: Error
PID     : 13107252             TID  : 6762        PROC : db2sysc 0
INSTANCE: ldapdb2              NODE : 000
EDUID   : 6762                 EDUNAME: db2logmgr (AMDB) 0
FUNCTION: DB2 UDB, data protection services, sqlpInitVendorDevice, probe:1030
MESSAGE : ZRC=0x86100025=-2045771739=SQLP_MEDIA_VENDOR_DEV_ERR
          "A vendor device reported a media error."
DATA #1 : String, 29 bytes
Init failed!  Vendor rc info:
DATA #2 : Vendor RC, PD_DB2_TYPE_VENDOR_RC, 4 bytes
Vendor RC=0x0000000B=11 -- see DB2 API Guide for meaning.
DATA #3 : Hexdump, 48 bytes
0x07000001B02E8AD0 : FFFF FFCE 3430 3520 2D35 3000 0000 0000    ....405 -50.....
0x07000001B02E8AE0 : 0000 0000 0000 0000 0000 0000 0000 0000    ................
0x07000001B02E8AF0 : 0000 0000 0000 0000 0000 0000 0000 0000    ................

2015-01-05-19.21.54.478819+000 I8485438A425       LEVEL: Error
PID     : 13107252             TID  : 6762        PROC : db2sysc 0
INSTANCE: ldapdb2              NODE : 000
EDUID   : 6762                 EDUNAME: db2logmgr (AMDB) 0
FUNCTION: DB2 UDB, data protection services, sqlpgArchiveLogVendor, probe:1820
RETCODE : ZRC=0x86100025=-2045771739=SQLP_MEDIA_VENDOR_DEV_ERR
          "A vendor device reported a media error."

2015-01-05-19.21.54.478930+000 E8485864A458       LEVEL: Warning
PID     : 13107252             TID  : 6762        PROC : db2sysc 0
INSTANCE: ldapdb2              NODE : 000
EDUID   : 6762                 EDUNAME: db2logmgr (AMDB) 0
FUNCTION: DB2 UDB, data protection services, sqlpgArchiveLogFile, probe:3150
MESSAGE : ADM1848W  Failed to archive log file "S0000607.LOG" to "TSM chain 0"
          from "/home/ldapdb2/ldapdb2/NODE0000/SQL00001/SQLOGDIR/".

2015-01-05-19.21.54.479227+000 E8486323A559       LEVEL: Error
PID     : 13107252             TID  : 6762        PROC : db2sysc 0
INSTANCE: ldapdb2              NODE : 000
EDUID   : 6762                 EDUNAME: db2logmgr (AMDB) 0
FUNCTION: DB2 UDB, data protection services, sqlpgArchiveLogFile, probe:3160
MESSAGE : ZRC=0x86100025=-2045771739=SQLP_MEDIA_VENDOR_DEV_ERR
          "A vendor device reported a media error."
DATA #1 : <preformatted>
Failed to archive log file S0000607.LOG to TSM chain 0 from /home/ldapdb2/ldapdb2/NODE0000/SQL00001/SQLOGDIR/.