NAME¶
zstream —
manipulate ZFS send streams
SYNOPSIS¶
zstream |
dump
[-Cvd]
[file] |
zstream |
decompress
[-v]
[object,offset[,type...]] |
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 …
