ZSTREAM(8) FreeBSD System Manager's Manual ZSTREAM(8)
NAME
zstream - manipulate ZFS send streams
SYNOPSIS
zstream dump [-Cvd] [file]
zstream decompress [-v] [object,offset[,type...]]
zstream redup [-v] file
zstream token resume_token
zstream recompress [-l level] algorithm
DESCRIPTION
The zstream utility manipulates ZFS send streams output by the zfs send
command.
zstream dump [-Cvd] [file]
Print information about the specified send stream, including headers
and record counts. The send stream may either be in the specified
file, or provided on standard input.
-C Suppress the validation of checksums.
-v Verbose. Print metadata for each record.
-d Dump data contained in each record. Implies verbose.
The zstreamdump alias is provided for compatibility and is equivalent
to running zstream dump.
zstream token resume_token
Dumps zfs resume token information
zstream decompress [-v] [object,offset[,type...]]
Decompress selected records in a ZFS send stream provided on standard
input, when the compression type recorded in ZFS metadata may be
incorrect. Specify the object number and byte offset of each record
that you wish to decompress. Optionally specify the compression type.
Valid compression types include off, gzip, lz4, lzjb, zstd, and zle.
The default is lz4. Every record for that object beginning at that
offset will be decompressed, if possible. It may not be possible,
because the record may be corrupted in some but not all of the stream's
snapshots. Specifying a compression type of off will change the
stream's metadata accordingly, without attempting decompression. This
can be useful if the record is already uncompressed but the metadata
insists otherwise. The repaired stream will be written to standard
output.
-v Verbose. Print summary of decompressed records.
zstream redup [-v] file
Deduplicated send streams can be generated by using the zfs send -D
command. The ability to send deduplicated send streams is deprecated.
In the future, the ability to receive a deduplicated send stream with
zfs receive will be removed. However, deduplicated send streams can
still be received by utilizing zstream redup.
The zstream redup command is provided a file containing a deduplicated
send stream, and outputs an equivalent non-deduplicated send stream on
standard output. Therefore, a deduplicated send stream can be received
by running:
# zstream redup DEDUP_STREAM_FILE | zfs receive <?>
-v Verbose. Print summary of converted records.
zstream recompress [-l level] algorithm
Recompresses a send stream, provided on standard input, using the
provided algorithm and optional level, and writes the modified stream
to standard output. All WRITE records in the send stream will be
recompressed, unless they fail to result in size reduction compared to
being left uncompressed. The provided algorithm can be any valid value
to the compress property. Note that encrypted send streams cannot be
recompressed.
-l level
Specifies compression level. Only needed for algorithms where the
level is not implied as part of the name of the algorithm (e.g.
gzip-3 does not require it, while zstd does, if a non-default level
is desired).
EXAMPLES
Heal a dataset that was corrupted due to OpenZFS bug #12762. First,
determine which records are corrupt. That cannot be done automatically;
it requires information beyond ZFS's metadata. If object 128 is
corrupted at offset 0 and is compressed using lz4, then run this command:
# zfs send -c <?> | zstream decompress 128,0,lz4 | zfs recv <?>
SEE ALSO
zfs(8), zfs-receive(8), zfs-send(8),
https://github.com/openzfs/zfs/issues/12762
FreeBSD 15.1-STABLE-HBSD November 10, 2022 ZSTREAM(8)