Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.\"
|
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|
|
.\" CDDL HEADER START
|
|
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|
.\"
|
|
|
|
.\" The contents of this file are subject to the terms of the
|
|
|
|
.\" Common Development and Distribution License (the "License").
|
|
|
|
.\" You may not use this file except in compliance with the License.
|
|
|
|
.\"
|
|
|
|
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
|
2022-07-11 21:16:13 +00:00
|
|
|
.\" or https://opensource.org/licenses/CDDL-1.0.
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.\" See the License for the specific language governing permissions
|
|
|
|
.\" and limitations under the License.
|
|
|
|
.\"
|
|
|
|
.\" When distributing Covered Code, include this CDDL HEADER in each
|
|
|
|
.\" file and include the License file at usr/src/OPENSOLARIS.LICENSE.
|
|
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.\" If applicable, add the following below this CDDL HEADER, with the
|
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|
.\" fields enclosed by brackets "[]" replaced with your own identifying
|
|
|
|
.\" information: Portions Copyright [yyyy] [name of copyright owner]
|
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.\"
|
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.\" CDDL HEADER END
|
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.\"
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.\" Copyright (c) 2020 by Delphix. All rights reserved.
|
2021-05-27 00:46:40 +00:00
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|
.\"
|
2022-10-14 20:40:00 +00:00
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|
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.Dd October 4, 2022
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.Dt ZSTREAM 8
|
2020-08-21 18:55:47 +00:00
|
|
|
.Os
|
2021-05-27 00:46:40 +00:00
|
|
|
.
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.Sh NAME
|
|
|
|
.Nm zstream
|
2021-05-27 00:46:40 +00:00
|
|
|
.Nd manipulate ZFS send streams
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.Sh SYNOPSIS
|
|
|
|
.Nm
|
|
|
|
.Cm dump
|
|
|
|
.Op Fl Cvd
|
|
|
|
.Op Ar file
|
|
|
|
.Nm
|
2022-06-24 20:28:42 +00:00
|
|
|
.Cm decompress
|
|
|
|
.Op Fl v
|
|
|
|
.Op Ar object Ns Sy \&, Ns Ar offset Ns Op Sy \&, Ns Ar type Ns ...
|
|
|
|
.Nm
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.Cm redup
|
|
|
|
.Op Fl v
|
|
|
|
.Ar file
|
2020-07-24 00:44:03 +00:00
|
|
|
.Nm
|
|
|
|
.Cm token
|
|
|
|
.Ar resume_token
|
2021-05-27 00:46:40 +00:00
|
|
|
.
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.Sh DESCRIPTION
|
|
|
|
The
|
|
|
|
.Sy zstream
|
2021-05-27 00:46:40 +00:00
|
|
|
utility manipulates ZFS send streams output by the
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.Sy zfs send
|
|
|
|
command.
|
|
|
|
.Bl -tag -width ""
|
|
|
|
.It Xo
|
|
|
|
.Nm
|
|
|
|
.Cm dump
|
|
|
|
.Op Fl Cvd
|
|
|
|
.Op Ar file
|
|
|
|
.Xc
|
|
|
|
Print information about the specified send stream, including headers and
|
|
|
|
record counts.
|
|
|
|
The send stream may either be in the specified
|
|
|
|
.Ar file ,
|
|
|
|
or provided on standard input.
|
|
|
|
.Bl -tag -width "-D"
|
|
|
|
.It Fl C
|
|
|
|
Suppress the validation of checksums.
|
|
|
|
.It Fl v
|
|
|
|
Verbose.
|
|
|
|
Print metadata for each record.
|
|
|
|
.It Fl d
|
|
|
|
Dump data contained in each record.
|
|
|
|
Implies verbose.
|
|
|
|
.El
|
2021-05-08 13:04:48 +00:00
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Nm zstreamdump
|
|
|
|
alias is provided for compatibility and is equivalent to running
|
|
|
|
.Nm
|
|
|
|
.Cm dump .
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.It Xo
|
|
|
|
.Nm
|
2020-07-24 00:44:03 +00:00
|
|
|
.Cm token
|
|
|
|
.Ar resume_token
|
|
|
|
.Xc
|
|
|
|
Dumps zfs resume token information
|
|
|
|
.It Xo
|
|
|
|
.Nm
|
2022-06-24 20:28:42 +00:00
|
|
|
.Cm decompress
|
|
|
|
.Op Fl v
|
|
|
|
.Op Ar object Ns Sy \&, Ns Ar offset Ns Op Sy \&, Ns Ar type Ns ...
|
|
|
|
.Xc
|
|
|
|
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
|
2022-10-14 20:40:00 +00:00
|
|
|
.Sy off ,
|
2022-06-24 20:28:42 +00:00
|
|
|
.Sy gzip ,
|
|
|
|
.Sy lz4 ,
|
|
|
|
.Sy lzjb ,
|
|
|
|
.Sy zstd ,
|
|
|
|
and
|
|
|
|
.Sy zle .
|
|
|
|
The default is
|
|
|
|
.Sy 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.
|
2022-10-14 20:40:00 +00:00
|
|
|
Specifying a compression type of
|
|
|
|
.Sy 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.
|
2022-06-24 20:28:42 +00:00
|
|
|
The repaired stream will be written to standard output.
|
|
|
|
.Bl -tag -width "-v"
|
|
|
|
.It Fl v
|
|
|
|
Verbose.
|
|
|
|
Print summary of decompressed records.
|
|
|
|
.El
|
|
|
|
.It Xo
|
|
|
|
.Nm
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.Cm redup
|
|
|
|
.Op Fl v
|
|
|
|
.Ar file
|
|
|
|
.Xc
|
|
|
|
Deduplicated send streams can be generated by using the
|
|
|
|
.Nm zfs Cm send Fl D
|
|
|
|
command.
|
|
|
|
The ability to send deduplicated send streams is deprecated.
|
|
|
|
In the future, the ability to receive a deduplicated send stream with
|
|
|
|
.Nm zfs Cm receive
|
|
|
|
will be removed.
|
|
|
|
However, deduplicated send streams can still be received by utilizing
|
|
|
|
.Nm zstream Cm redup .
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Nm zstream Cm redup
|
|
|
|
command is provided a
|
|
|
|
.Ar 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:
|
2021-05-27 00:46:40 +00:00
|
|
|
.Dl # Nm zstream Cm redup Pa DEDUP_STREAM_FILE | Nm zfs Cm receive No …
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.Bl -tag -width "-D"
|
|
|
|
.It Fl v
|
|
|
|
Verbose.
|
|
|
|
Print summary of converted records.
|
2021-05-10 15:24:59 +00:00
|
|
|
.El
|
|
|
|
.El
|
2021-05-27 00:46:40 +00:00
|
|
|
.
|
2022-06-24 20:28:42 +00:00
|
|
|
.Sh 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
|
|
|
|
.Sy 128
|
|
|
|
is corrupted at offset
|
|
|
|
.Sy 0
|
|
|
|
and is compressed using
|
|
|
|
.Sy lz4 ,
|
|
|
|
then run this command:
|
|
|
|
.Bd -literal
|
|
|
|
.No # Nm zfs Ar send Fl c Ar … | Nm zstream decompress Ar 128,0,lz4 | \
|
|
|
|
Nm zfs recv Ar …
|
|
|
|
.Ed
|
Add `zstream redup` command to convert deduplicated send streams
Deduplicated send and receive is deprecated. To ease migration to the
new dedup-send-less world, the commit adds a `zstream redup` utility to
convert deduplicated send streams to normal streams, so that they can
continue to be received indefinitely.
The new `zstream` command also replaces the functionality of
`zstreamdump`, by way of the `zstream dump` subcommand. The
`zstreamdump` command is replaced by a shell script which invokes
`zstream dump`.
The way that `zstream redup` works under the hood is that as we read the
send stream, we build up a hash table which maps from `<GUID, object,
offset> -> <file_offset>`.
Whenever we see a WRITE record, we add a new entry to the hash table,
which indicates where in the stream file to find the WRITE record for
this block. (The key is `drr_toguid, drr_object, drr_offset`.)
For entries other than WRITE_BYREF, we pass them through unchanged
(except for the running checksum, which is recalculated).
For WRITE_BYREF records, we change them to WRITE records. We find the
referenced WRITE record by looking in the hash table (for the record
with key `drr_refguid, drr_refobject, drr_refoffset`), and then reading
the record header and payload from the specified offset in the stream
file. This is why the stream can not be a pipe. The found WRITE record
replaces the WRITE_BYREF record, with its `drr_toguid`, `drr_object`,
and `drr_offset` fields changed to be the same as the WRITE_BYREF's
(i.e. we are writing the same logical block, but with the data supplied
by the previous WRITE record).
This algorithm requires memory proportional to the number of WRITE
records (same as `zfs send -D`), but the size per WRITE record is
relatively low (40 bytes, vs. 72 for `zfs send -D`). A 1TB send stream
with 8KB blocks (`recordsize=8k`) would use around 5GB of RAM to
"redup".
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10124
Closes #10156
2020-04-10 17:39:55 +00:00
|
|
|
.Sh SEE ALSO
|
|
|
|
.Xr zfs 8 ,
|
2021-05-27 00:46:40 +00:00
|
|
|
.Xr zfs-receive 8 ,
|
2022-06-24 20:28:42 +00:00
|
|
|
.Xr zfs-send 8 ,
|
|
|
|
.Lk https://github.com/openzfs/zfs/issues/12762
|