cqlsh:manual_test> create columnfamily cf13 ( rowkey int primary key, b blob );

[default@manual_test] describe cf13;  
    ColumnFamily: cf13
      Key Validation Class: org.apache.cassandra.db.marshal.Int32Type
      Default column value validator: org.apache.cassandra.db.marshal.UTF8Type
      Columns sorted by: org.apache.cassandra.db.marshal.UTF8Type
      GC grace seconds: 864000
      Compaction min/max thresholds: 4/32
      Read repair chance: 0.1
      DC Local Read repair chance: 0.0
      Replicate on write: true
      Caching: KEYS_ONLY
      Bloom Filter FP chance: default
      Built indexes: []
      Column Metadata:
        Column Name: b
          Validation Class: org.apache.cassandra.db.marshal.BytesType
      Compaction Strategy: org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy
      Compression Options:
        sstable_compression: org.apache.cassandra.io.compress.SnappyCompressor

create table t13 (rowkey int primary key, b blob ) ENGINE=CASSANDRA `keyspace`='manual_test' `column_family`='cf13';
ERROR 1928 (HY000): Internal error: 'Failed to map column b to datatype org.apache.cassandra.db.marshal.BytesType'

create table t13 (rowkey int primary key, b varbinary(1024) ) ENGINE=CASSANDRA `keyspace`='manual_test' `column_family`='cf13';
# Query OK, 0 rows affected (0.04 sec)