Syntax

dd [ --if=name ] [ --of=name ] [ --bs=bytes ] [ --count=num ] 
   [ --ibs=bytes ] [ --obs=bytes ] [ --seek=num ] [ --skip=num ] 
   [ --imirror=num ] [ --omirror=num ] [ --mirror=num ] 
   [ --truncate ] [ --aio=naio ] [ --block ] 
   [ --status=status-level] [ --sparse ]
   [{ -w | --wallet } wallet-location ] 
   [{ -T | --trace } trace-level ] 
   [{ -j | --json } [ --compact ]]

Command Options

The options for the dd command are:

• --if: Specifies the name of the input file to use instead of standard input.

• --of: Specifies the name of the output file to use instead of standard output.

• --bs: Specifies the number of bytes to read and write in each block. The default value is 512.

• --count: Specifies the number of input blocks.

• --ibs: Specifies the number of bytes to read in each block. The default value is 512.

• --obs: Specifies the number of bytes to write in each block. The default value is 512.

• --seek: Specifies the number of blocks to skip at the start of the output.

• --skip: Specifies the number of blocks to skip at the start of the input.

• --imirror: Specifies the input mirror number. The first mirror is 0, the second mirror is 1, and so on. The default value is 255, which means 'read any mirror.'

• --omirror: Specifies the output mirror number. The first mirror is 0, the second mirror is 1, and so on. The default value is 255, which means 'write all mirrors.'

• --mirror: Specifies the input and output mirror number. The first mirror is 0, the second mirror is 1, and so on. The default value is 255, which means 'all mirrors.'

• --truncate Resizes the output file.

• --aio: Specifies the number of async I/Os to use. The default value is 4.

• --block: Specifies that the I/O offsets should be divisible by the relevant I/O block size.

• --status: Specifies the level of status information output during a long-running operation.

  Permitted values are:

  • progress: Periodically shows progress statistics.

  • none: Suppresses progress statistics and only shows applicable error messages. This is the default setting.

• --sparse: Tries to seek rather than write to output for Exascale sparse input blocks.

  This option only applies when copying files in Exascale storage.

• -w, --wallet: Optionally specifies the path to the Exascale wallet directory.

• -T, --trace: Optionally enables tracing, with the trace level (trace-level) set to 1 (minimum tracing), 2 (medium tracing), or 3 (maximum tracing). If the trace level is not specified, then minimum tracing is enabled by default.

  The trace file is written to the first accessible location in the following list:

  1. If the $ADR_BASE environment variable is set:

     $ADR_BASE/diag/EXC/xsh_<user-name>/<host-name>/trace/xsh_<date>.trc

  2. /var/log/oracle/diag/EXC/xsh_<user-name>/<host-name>/trace/xsh_<date>.trc

  3. /tmp/diag/EXC/xsh_<user-name>/<host-name>/trace/xsh_<date>.trc

• -j, --json: Displays the output in JSON format.

• --compact: Displays JSON formatted output in a compact format, without white space and line breaks.