Commit Graph

7 Commits

Author SHA1 Message Date
manfromafar
ecc277cff7
Clarify compressed zfs send/recv behavior
Docs for send and receive do not explain behavior when sending a 
compressed stream then receiving on a host that overrides compression 
with -o compress=value.

The data from the send stream is written as it was from the send is 
the compressed form but the compression algorithm set on the receiver 
is the overridden version which causes some confusion as to what 
algorithm was actually used.

Updated man docs to clarify behavior

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed By: Allan Jude <allanjude@freebsd.org>
Signed-off-by: manfromafar <manfromafar@outlook.com>
Closes #11690
2021-03-07 09:39:16 -08:00
xtouqh
1e36af8c7b
Properly format NAME subsection of zfs/zpool subcommands
Use proper names (i.e. zfs-allow and zpool-add) in NAME subsections
of zfs/zpool subcommands instead of current "pretty-printed" ones as
makewhatis utilities (or some implementations of it, namely the one
from mandoc suite used in FreeBSD) look not only at the document title
but also in NAME subsection, adding zfs(8)/zpool(8) to search results
which is not correct. (Common sense and other utilities splitting
subcommands in multiple man pages, e.g. git, do the same.)

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: xtouqh <xtouqh@hotmail.com>
Closes #11086
2020-10-22 11:28:10 -07:00
Ryan Moeller
6706552ea6
Remove hard coded "Linux" OS from manpages
The recommended practice for `.Os` on FreeBSD is to not specify any
arguments.  The correct OS name is used automatically.

Oddly enough, on the Linux distro I tested this on (CentOS 7), the man
pager defaulted to displaying "BSD" as the OS rather than "Linux".  To
accommodate this, tack " Linux" back on in an install hook on Linux.
This is much simpler than removing it for FreeBSD when vendored in the
base system.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10760
2020-08-21 11:55:47 -07:00
Matthew Ahrens
196bee4cfd
Remove deduplicated send/receive code
Deduplicated send streams (i.e. `zfs send -D` and `zfs receive` of such
streams) are deprecated.  Deduplicated send streams can be received by
first converting them to non-deduplicated with the `zstream redup`
command.

This commit removes the code for sending and receiving deduplicated send
streams.  `zfs send -D` will now print a warning, ignore the `-D` flag,
and generate a regular (non-deduplicated) send stream.  `zfs receive` of
a deduplicated send stream will print an error message and fail.

The resulting code simplification (especially in the kernel's support
for receiving dedup streams) should help enable future performance
enhancements.

Several new tests are added which leverage `zstream redup`.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Issue #7887
Issue #10117
Issue #10156
Closes #10212
2020-04-23 10:06:57 -07:00
Matthew Ahrens
652bdc9b0e
Deprecate deduplicated send streams
Dedup send can only deduplicate over the set of blocks in the send
command being invoked, and it does not take advantage of the dedup table
to do so. This is a very common misconception among not only users, but
developers, and makes the feature seem more useful than it is. As a
result, many users are using the feature but not getting any benefit
from it.

Dedup send requires a nontrivial expenditure of memory and CPU to
operate, especially if the dataset(s) being sent is (are) not already
using a dedup-strength checksum.

Dedup send adds developer burden. It expands the test matrix when
developing new features, causing bugs in released code, and delaying
development efforts by forcing more testing to be done.

As a result, we are deprecating the use of `zfs send -D` and receiving
of such streams.  This change adds a warning to the man page, and also
prints the warning whenever dedup send or receive are used.

In a future release, we plan to:
1. remove the kernel code for generating deduplicated streams
2. make `zfs send -D` generate regular, non-deduplicated streams
3. remove the kernel code for receiving deduplicated streams
4. make `zfs receive` of deduplicated streams process them in userland
   to "re-duplicate" them, so that they can still be received.

Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #7887 
Closes #10117
2020-03-18 13:31:10 -07:00
Mariusz Zaborski
a57d3d45d6
Add option for forcible unmounting dataset while receiving snapshot.
Currently when the dataset is in use we can't receive snapshots.

    zfs send test/1@asd | zfs recv -FM test/2
    cannot unmount '/test/2': Device busy

This commits add option 'M' which attempts to forcibly unmount the
dataset.  Thanks to this we can enforce receiving snapshots in a
single step.

Note that this functionality is not supported on Linux because the
VFS will prevent active mounted filesystems from being unmounted,
even with the force option.  This is the intended VFS behavior.

Test cases were added to verify the expected behavior based on
the platform.

Discussed-with: Pawel Jakub Dawidek <pjd@FreeBSD.org>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Allan Jude <allanjude@freebsd.org>
External-issue: https://reviews.freebsd.org/D22306
Closes #9904
2020-03-17 10:08:32 -07:00
Ross Williams
870fc32fc9 Reorganize zfs(8) man page into sections
Most subcommands got their own manpages (e.g. create). Some related
commands grouped into a single manpage and symlinks created (e.g. set, 
get, and inherit). I did this when topics were either too short to 
warrant their own file or so interrelated that a user would want to
refer between commands in the same file.

Corrected .Sx internal references to .Xr cross refs; lots of .Sx 
references from when text was all in zfs.8 needed to be changed to 
.Xr zfs-$SUBCOMMAND 8 cross references.

Divided subcommand list in zfs(8) into sections of related 
functionality. This required writing new descriptions for some 
commands.

Preserved ".Os Linux", `.Os` macro parsing behavior differs between 
mandoc from the "BSD" mandoc package (available on Ubuntu) and man 
from Ubuntu's man-db package, which calls groff to format the manpages.

Groff handles the `.Os` macro differently and wrongly, defaulting 
it to "BSD" in `/usr/share/groff/*/tmac/mdoc/doc-common`, instead of
getting the default from `uname`.

A future set of changes will introduce build-time preprocessing of
manpages for platform-specific documentation and can insert the
correct operating system name.

Added SEE ALSO sections, the newly-divided zfs-*.8 subcommand man
pages needed their own SEE ALSO sections pointing to related
subcommands and, in some cases, documentation from other packages
(e.g. zfs-share.8).

Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Kjeld Schouten <kjeld@schouten-lebbing.nl>
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ross Williams <ross@ross-williams.net>
Closes #9559
2019-11-12 11:17:40 -08:00