2383671 - Drop data volume failed

You want to delete a volume, but it fails with "Drop data volume failed - volume x still contains yy pages"

You can see following errors in the trace files:

dbm.prt

INF          1 DBMSrvCo A DBM Server client connection was established at 2016-10-20 11:52:14
INF        283 DBMSrv   Command 'db_deletevolume DATA 1' is being executed.
INF          1 DBMKnl   Sending an administrative statement to the database TST on computer localhost
INF          8 DBMKnl   Statement:  DROP DATA VOLUME 1
ERR          3 DBMKnl   Received the result of an administrative statement from the database TST on computer localhost
ERR          9 DBMKnl   Statement:  DROP DATA VOLUME 1
ERR         10 DBMKnl   Returncode: -9407
ERR          5 DBMKnl   Errortext:  System error: unexpected error
ERR     -24988 DBMSrv   ERR_SQL: SQL error
INF          0 DBMSrv   -9407,System error: unexpected error
INF          0 DBMSrv   20077,Drop data volume failed - volume 1 still contains 34 pages

KnlMsg

    IOMan      20019:  Start reading pages from data volume 1 for dropping
    IOMan      20020:  Stop reading pages from data volume 1 for dropping
    Savepoint      1:  Savepoint (DropVolume) with ID 262363 started
    DataCache     12:  Savepoint (phase 1): Start write data
    DataCache     13:  Savepoint (phase 1): Stop write data, 2622 pages written with 372 io calls
    DataCache     12:  Savepoint (phase 2): Start write data
    DataCache     13:  Savepoint (phase 2): Stop write data, 0 pages written with 0 io calls
    DataCache      4:  Mark data pages for savepoint (prepare phase)
    DataCache     12:  Savepoint (phase 3): Start write data
    DataCache     13:  Savepoint (phase 3): Stop write data, 3 pages written with 1 io calls
    Converter  20047:  Savepoint (phase 3): Start write converter
    Converter  20048:  Savepoint (phase 3): Stop write converter, 1383 pages written with 1383 io calls
    DataCache      3:  Savepoint with ID 262363 completed
    FBM        20000:  BlockNo: 30424 is still in use, state: Occupied
    FBM        20000:  BlockNo: 241200 is still in use, state: Occupied
    ...
    FBM        20000:  BlockNo: 633875 is still in use, state: Occupied
    FBM        20000:  BlockNo: 673377 is still in use, state: Occupied
    FBM        20000:  BlockNo: 685432 is still in use, state: Occupied
    FBM        20000:  BlockNo: 686585 is still in use, state: Occupied
ERR SYSERROR   51080:  -9407 unexpected error
ERR IOMan      20077:  Drop data volume failed - volume 1 still contains 34 pages,_FILE=IOMan_DataFileSystem+noPIC.cpp,_LINE=1104

MaxDB/liveCache databases

drop, delete, volume , KBA , BC-DB-SDB , MaxDB , BC-DB-LVC , liveCache , How To