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Diffstat (limited to 'man/man8/zfs-program.8')
| -rw-r--r-- | man/man8/zfs-program.8 | 416 |
1 files changed, 205 insertions, 211 deletions
diff --git a/man/man8/zfs-program.8 b/man/man8/zfs-program.8 index 02251ae7c..4a9718cdc 100644 --- a/man/man8/zfs-program.8 +++ b/man/man8/zfs-program.8 @@ -1,3 +1,4 @@ +.\" .\" This file and its contents are supplied under the terms of the .\" Common Development and Distribution License ("CDDL"), version 1.0. .\" You may only use this file in accordance with the terms of version @@ -7,17 +8,17 @@ .\" source. A copy of the CDDL is also available via the Internet at .\" http://www.illumos.org/license/CDDL. .\" -.\" .\" Copyright (c) 2016, 2019 by Delphix. All Rights Reserved. .\" Copyright (c) 2019, 2020 by Christian Schwarz. All Rights Reserved. .\" Copyright 2020 Joyent, Inc. .\" -.Dd January 26, 2021 +.Dd May 27, 2021 .Dt ZFS-PROGRAM 8 .Os +. .Sh NAME .Nm zfs-program -.Nd executes ZFS channel programs +.Nd execute ZFS channel programs .Sh SYNOPSIS .Nm zfs .Cm program @@ -26,7 +27,8 @@ .Op Fl m Ar memory-limit .Ar pool .Ar script -.\".Op Ar optional arguments to channel program +.Op Ar script arguments +. .Sh DESCRIPTION The ZFS channel program interface allows ZFS administrative operations to be run programmatically as a Lua script. @@ -37,22 +39,22 @@ Channel programs may only be run with root privileges. .Pp A modified version of the Lua 5.2 interpreter is used to run channel program scripts. -The Lua 5.2 manual can be found at: -.Bd -centered -offset indent +The Lua 5.2 manual can be found at .Lk http://www.lua.org/manual/5.2/ -.Ed .Pp The channel program given by .Ar script will be run on .Ar pool , and any attempts to access or modify other pools will cause an error. +. .Sh OPTIONS .Bl -tag -width "-t" .It Fl j -Display channel program output in JSON format. When this flag is specified and -standard output is empty - channel program encountered an error. The details of -such an error will be printed to standard error in plain text. +Display channel program output in JSON format. +When this flag is specified and standard output is empty - +channel program encountered an error. +The details of such an error will be printed to standard error in plain text. .It Fl n Executes a read-only channel program, which runs faster. The program cannot change on-disk state by calling functions from the @@ -78,15 +80,17 @@ All remaining argument strings will be passed directly to the Lua script as described in the .Sx LUA INTERFACE section below. +. .Sh LUA INTERFACE A channel program can be invoked either from the command line, or via a library call to .Fn lzc_channel_program . +. .Ss Arguments Arguments passed to the channel program are converted to a Lua table. If invoked from the command line, extra arguments to the Lua script will be accessible as an array stored in the argument table with the key 'argv': -.Bd -literal -offset indent +.Bd -literal -compact -offset indent args = ... argv = args["argv"] -- argv == {1="arg1", 2="arg2", ...} @@ -95,7 +99,7 @@ argv = args["argv"] If invoked from the libZFS interface, an arbitrary argument list can be passed to the channel program, which is accessible via the same "..." syntax in Lua: -.Bd -literal -offset indent +.Bd -literal -compact -offset indent args = ... -- args == {"foo"="bar", "baz"={...}, ...} .Ed @@ -108,37 +112,35 @@ in in a C array passed to a channel program will be stored in .Va arr[1] when accessed from Lua. +. .Ss Return Values Lua return statements take the form: -.Bd -literal -offset indent -return ret0, ret1, ret2, ... -.Ed +.Dl return ret0, ret1, ret2, ... .Pp Return statements returning multiple values are permitted internally in a channel program script, but attempting to return more than one value from the top level of the channel program is not permitted and will throw an error. However, tables containing multiple values can still be returned. If invoked from the command line, a return statement: -.Bd -literal -offset indent +.Bd -literal -compact -offset indent a = {foo="bar", baz=2} return a .Ed .Pp Will be output formatted as: -.Bd -literal -offset indent +.Bd -literal -compact -offset indent Channel program fully executed with return value: return: baz: 2 foo: 'bar' .Ed +. .Ss Fatal Errors If the channel program encounters a fatal error while running, a non-zero exit status will be returned. If more information about the error is available, a singleton list will be returned detailing the error: -.Bd -literal -offset indent -error: "error string, including Lua stack trace" -.Ed +.Dl error: \&"error string, including Lua stack trace" .Pp If a fatal error is returned, the channel program may have not executed at all, may have partially executed, or may have fully executed but failed to pass a @@ -162,6 +164,7 @@ return an error code and the channel program continues executing. See the .Sx ZFS API section below for function-specific details on error return codes. +. .Ss Lua to C Value Conversion When invoking a channel program via the libZFS interface, it is necessary to translate arguments and return values from Lua values to their C equivalents, @@ -171,37 +174,37 @@ There is a correspondence between nvlist values in C and Lua tables. A Lua table which is returned from the channel program will be recursively converted to an nvlist, with table values converted to their natural equivalents: -.Bd -literal -offset indent -string -> string -number -> int64 -boolean -> boolean_value -nil -> boolean (no value) -table -> nvlist -.Ed +.TS +cw3 l c l . + string -> string + number -> int64 + boolean -> boolean_value + nil -> boolean (no value) + table -> nvlist +.TE .Pp Likewise, table keys are replaced by string equivalents as follows: -.Bd -literal -offset indent -string -> no change -number -> signed decimal string ("%lld") -boolean -> "true" | "false" -.Ed +.TS +cw3 l c l . + string -> no change + number -> signed decimal string ("%lld") + boolean -> "true" | "false" +.TE .Pp Any collision of table key strings (for example, the string "true" and a true boolean value) will cause a fatal error. .Pp Lua numbers are represented internally as signed 64-bit integers. +. .Sh LUA STANDARD LIBRARY The following Lua built-in base library functions are available: -.Bd -literal -offset indent -assert rawlen -collectgarbage rawget -error rawset -getmetatable select -ipairs setmetatable -next tonumber -pairs tostring -rawequal type -.Ed +.TS +cw3 l l l l . + assert rawlen collectgarbage rawget + error rawset getmetatable select + ipairs setmetatable next tonumber + pairs tostring rawequal type +.TE .Pp All functions in the .Em coroutine , @@ -214,15 +217,13 @@ manual. .Pp The following functions base library functions have been disabled and are not available for use in channel programs: -.Bd -literal -offset indent -dofile -loadfile -load -pcall -print -xpcall -.Ed +.TS +cw3 l l l l l l . + dofile loadfile load pcall print xpcall +.TE +. .Sh ZFS API +. .Ss Function Arguments Each API function takes a fixed set of required positional arguments and optional keyword arguments. @@ -231,22 +232,17 @@ For example, the destroy function takes a single positional string argument argument. When using parentheses to specify the arguments to a Lua function, only positional arguments can be used: -.Bd -literal -offset indent -zfs.sync.destroy("rpool@snap") -.Ed +.Dl Sy zfs.sync.destroy Ns Pq \&"rpool@snap" .Pp To use keyword arguments, functions must be called with a single argument that is a Lua table containing entries mapping integers to positional arguments and strings to keyword arguments: -.Bd -literal -offset indent -zfs.sync.destroy({1="rpool@snap", defer=true}) -.Ed +.Dl Sy zfs.sync.destroy Ns Pq {1="rpool@snap", defer=true} .Pp The Lua language allows curly braces to be used in place of parenthesis as syntactic sugar for this calling convention: -.Bd -literal -offset indent -zfs.sync.snapshot{"rpool@snap", defer=true} -.Ed +.Dl Sy zfs.sync.snapshot Ns {"rpool@snap", defer=true} +. .Ss Function Return Values If an API function succeeds, it returns 0. If it fails, it returns an error code and the channel program continues @@ -261,13 +257,11 @@ Lua table, or Nil if no error details were returned. Different keys will exist in the error details table depending on the function and error case. Any such function may be called expecting a single return value: -.Bd -literal -offset indent -errno = zfs.sync.promote(dataset) -.Ed +.Dl errno = Sy zfs.sync.promote Ns Pq dataset .Pp Or, the error details can be retrieved: -.Bd -literal -offset indent -errno, details = zfs.sync.promote(dataset) +.Bd -literal -compact -offset indent +.No errno, details = Sy zfs.sync.promote Ns Pq dataset if (errno == EEXIST) then assert(details ~= Nil) list_of_conflicting_snapshots = details @@ -276,48 +270,46 @@ end .Pp The following global aliases for API function error return codes are defined for use in channel programs: -.Bd -literal -offset indent -EPERM ECHILD ENODEV ENOSPC -ENOENT EAGAIN ENOTDIR ESPIPE -ESRCH ENOMEM EISDIR EROFS -EINTR EACCES EINVAL EMLINK -EIO EFAULT ENFILE EPIPE -ENXIO ENOTBLK EMFILE EDOM -E2BIG EBUSY ENOTTY ERANGE -ENOEXEC EEXIST ETXTBSY EDQUOT -EBADF EXDEV EFBIG -.Ed +.TS +cw3 l l l l l l l . + EPERM ECHILD ENODEV ENOSPC ENOENT EAGAIN ENOTDIR + ESPIPE ESRCH ENOMEM EISDIR EROFS EINTR EACCES + EINVAL EMLINK EIO EFAULT ENFILE EPIPE ENXIO + ENOTBLK EMFILE EDOM E2BIG EBUSY ENOTTY ERANGE + ENOEXEC EEXIST ETXTBSY EDQUOT EBADF EXDEV EFBIG +.TE +. .Ss API Functions -For detailed descriptions of the exact behavior of any zfs administrative +For detailed descriptions of the exact behavior of any ZFS administrative operations, see the main .Xr zfs 8 manual page. .Bl -tag -width "xx" -.It Em zfs.debug(msg) +.It Fn zfs.debug msg Record a debug message in the zfs_dbgmsg log. A log of these messages can be printed via mdb's "::zfs_dbgmsg" command, or -can be monitored live by running: -.Bd -literal -offset indent - dtrace -n 'zfs-dbgmsg{trace(stringof(arg0))}' -.Ed +can be monitored live by running +.Dl dtrace -n 'zfs-dbgmsg{trace(stringof(arg0))}' .Pp -msg (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "property (string)" +.It Ar msg Pq string Debug message to be printed. -.Ed -.It Em zfs.exists(dataset) +.El +.It Fn zfs.exists dataset Returns true if the given dataset exists, or false if it doesn't. A fatal error will be thrown if the dataset is not in the target pool. That is, in a channel program running on rpool, -zfs.exists("rpool/nonexistent_fs") returns false, but -zfs.exists("somepool/fs_that_may_exist") will error. +.Sy zfs.exists Ns Pq \&"rpool/nonexistent_fs" +returns false, but +.Sy zfs.exists Ns Pq \&"somepool/fs_that_may_exist" +will error. .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "property (string)" +.It Ar dataset Pq string Dataset to check for existence. Must be in the target pool. -.Ed -.It Em zfs.get_prop(dataset, property) +.El +.It Fn zfs.get_prop dataset property Returns two values. First, a string, number or table containing the property value for the given dataset. @@ -326,22 +318,25 @@ dataset in which it was set or nil if it is readonly). Throws a Lua error if the dataset is invalid or the property doesn't exist. Note that Lua only supports int64 number types whereas ZFS number properties are uint64. -This means very large values (like guid) may wrap around and appear negative. +This means very large values (like GUIDs) may wrap around and appear negative. .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "property (string)" +.It Ar dataset Pq string Filesystem or snapshot path to retrieve properties from. -.Ed -.Pp -property (string) -.Bd -ragged -compact -offset "xxxx" +.It Ar property Pq string Name of property to retrieve. -All filesystem, snapshot and volume properties are supported except -for 'mounted' and 'iscsioptions.' -Also supports the 'written@snap' and 'written#bookmark' properties and -the '<user|group><quota|used>@id' properties, though the id must be in numeric -form. -.Ed +All filesystem, snapshot and volume properties are supported except for +.Sy mounted +and +.Sy iscsioptions . +Also supports the +.Sy written@ Ns Ar snap +and +.Sy written# Ns Ar bookmark +properties and the +.Ao Sy user Ns | Ns Sy group Ac Ns Ao Sy quota Ns | Ns Sy used Ac Ns Sy @ Ns Ar id +properties, though the id must be in numeric form. +.El .El .Bl -tag -width "xx" .It Sy zfs.sync submodule @@ -350,86 +345,73 @@ They are executed in "syncing context". .Pp The available sync submodule functions are as follows: .Bl -tag -width "xx" -.It Em zfs.sync.destroy(dataset, [defer=true|false]) +.It Sy zfs.sync.destroy Ns Pq Ar dataset , Op Ar defer Ns = Ns Sy true Ns | Ns Sy false Destroy the given dataset. Returns 0 on successful destroy, or a nonzero error code if the dataset could not be destroyed (for example, if the dataset has any active children or clones). .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "newbookmark (string)" +.It Ar dataset Pq string Filesystem or snapshot to be destroyed. -.Ed -.Pp -[optional] defer (boolean) -.Bd -ragged -compact -offset "xxxx" +.It Op Ar defer Pq boolean Valid only for destroying snapshots. If set to true, and the snapshot has holds or clones, allows the snapshot to be marked for deferred deletion rather than failing. -.Ed -.It Em zfs.sync.inherit(dataset, property) +.El +.It Fn zfs.sync.inherit dataset property Clears the specified property in the given dataset, causing it to be inherited from an ancestor, or restored to the default if no ancestor property is set. The -.Ql zfs inherit -S +.Nm zfs Cm inherit Fl S option has not been implemented. Returns 0 on success, or a nonzero error code if the property could not be cleared. .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "newbookmark (string)" +.It Ar dataset Pq string Filesystem or snapshot containing the property to clear. -.Ed -.Pp -property (string) -.Bd -ragged -compact -offset "xxxx" +.It Ar property Pq string The property to clear. Allowed properties are the same as those for the .Nm zfs Cm inherit command. -.Ed -.It Em zfs.sync.promote(dataset) +.El +.It Fn zfs.sync.promote dataset Promote the given clone to a filesystem. Returns 0 on successful promotion, or a nonzero error code otherwise. If EEXIST is returned, the second return value will be an array of the clone's snapshots whose names collide with snapshots of the parent filesystem. .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "newbookmark (string)" +.It Ar dataset Pq string Clone to be promoted. -.Ed -.It Em zfs.sync.rollback(filesystem) +.El +.It Fn zfs.sync.rollback filesystem Rollback to the previous snapshot for a dataset. Returns 0 on successful rollback, or a nonzero error code otherwise. Rollbacks can be performed on filesystems or zvols, but not on snapshots or mounted datasets. EBUSY is returned in the case where the filesystem is mounted. .Pp -filesystem (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "newbookmark (string)" +.It Ar filesystem Pq string Filesystem to rollback. -.Ed -.It Em zfs.sync.set_prop(dataset, property, value) +.El +.It Fn zfs.sync.set_prop dataset property value Sets the given property on a dataset. Currently only user properties are supported. Returns 0 if the property was set, or a nonzero error code otherwise. .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "newbookmark (string)" +.It Ar dataset Pq string The dataset where the property will be set. -.Ed -.Pp -property (string) -.Bd -ragged -compact -offset "xxxx" +.It Ar property Pq string The property to set. -Only user properties are supported. -.Ed -.Pp -value (string) -.Bd -ragged -compact -offset "xxxx" +.It Ar value Pq string The value of the property to be set. -.Ed -.It Em zfs.sync.snapshot(dataset) +.El +.It Fn zfs.sync.snapshot dataset Create a snapshot of a filesystem. Returns 0 if the snapshot was successfully created, and a nonzero error code otherwise. @@ -437,132 +419,142 @@ and a nonzero error code otherwise. Note: Taking a snapshot will fail on any pool older than legacy version 27. To enable taking snapshots from ZCP scripts, the pool must be upgraded. .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "newbookmark (string)" +.It Ar dataset Pq string Name of snapshot to create. -.Ed -.It Em zfs.sync.bookmark(source, newbookmark) +.El +.It Fn zfs.sync.bookmark source newbookmark Create a bookmark of an existing source snapshot or bookmark. Returns 0 if the new bookmark was successfully created, and a nonzero error code otherwise. .Pp Note: Bookmarking requires the corresponding pool feature to be enabled. .Pp -source (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "newbookmark (string)" +.It Ar source Pq string Full name of the existing snapshot or bookmark. -.Ed -.Pp -newbookmark (string) -.Bd -ragged -compact -offset "xxxx" +.It Ar newbookmark Pq string Full name of the new bookmark. .El -.Ed +.El .It Sy zfs.check submodule -For each function in the zfs.sync submodule, there is a corresponding zfs.check +For each function in the +.Sy zfs.sync +submodule, there is a corresponding +.Sy zfs.check function which performs a "dry run" of the same operation. -Each takes the same arguments as its zfs.sync counterpart and returns 0 if the -operation would succeed, or a non-zero error code if it would fail, along with -any other error details. +Each takes the same arguments as its +.Sy zfs.sync +counterpart and returns 0 if the operation would succeed, +or a non-zero error code if it would fail, along with any other error details. That is, each has the same behavior as the corresponding sync function except for actually executing the requested change. For example, -.Em zfs.check.destroy("fs") +.Fn zfs.check.destroy \&"fs" returns 0 if -.Em zfs.sync.destroy("fs") +.Fn zfs.sync.destroy \&"fs" would successfully destroy the dataset. .Pp -The available zfs.check functions are: -.Bl -tag -width "xx" -.It Em zfs.check.destroy(dataset, [defer=true|false]) -.It Em zfs.check.promote(dataset) -.It Em zfs.check.rollback(filesystem) -.It Em zfs.check.set_property(dataset, property, value) -.It Em zfs.check.snapshot(dataset) +The available +.Sy zfs.check +functions are: +.Bl -tag -compact -width "xx" +.It Sy zfs.check.destroy Ns Pq Ar dataset , Op Ar defer Ns = Ns Sy true Ns | Ns Sy false +.It Fn zfs.check.promote dataset +.It Fn zfs.check.rollback filesystem +.It Fn zfs.check.set_property dataset property value +.It Fn zfs.check.snapshot dataset .El .It Sy zfs.list submodule The zfs.list submodule provides functions for iterating over datasets and properties. Rather than returning tables, these functions act as Lua iterators, and are generally used as follows: -.Bd -literal -offset indent -for child in zfs.list.children("rpool") do +.Bd -literal -compact -offset indent +.No for child in Fn zfs.list.children \&"rpool" No do ... end .Ed .Pp -The available zfs.list functions are: +The available +.Sy zfs.list +functions are: .Bl -tag -width "xx" -.It Em zfs.list.clones(snapshot) +.It Fn zfs.list.clones snapshot Iterate through all clones of the given snapshot. .Pp -snapshot (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "snapshot (string)" +.It Ar snapshot Pq string Must be a valid snapshot path in the current pool. -.Ed -.It Em zfs.list.snapshots(dataset) +.El +.It Fn zfs.list.snapshots dataset Iterate through all snapshots of the given dataset. -Each snapshot is returned as a string containing the full dataset name, e.g. -"pool/fs@snap". +Each snapshot is returned as a string containing the full dataset name, +e.g. "pool/fs@snap". .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "snapshot (string)" +.It Ar dataset Pq string Must be a valid filesystem or volume. -.Ed -.It Em zfs.list.children(dataset) +.El +.It Fn zfs.list.children dataset Iterate through all direct children of the given dataset. -Each child is returned as a string containing the full dataset name, e.g. -"pool/fs/child". +Each child is returned as a string containing the full dataset name, +e.g. "pool/fs/child". .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "snapshot (string)" +.It Ar dataset Pq string Must be a valid filesystem or volume. -.Ed -.It Em zfs.list.bookmarks(dataset) -Iterate through all bookmarks of the given dataset. Each bookmark is returned -as a string containing the full dataset name, e.g. "pool/fs#bookmark". +.El +.It Fn zfs.list.bookmarks dataset +Iterate through all bookmarks of the given dataset. +Each bookmark is returned as a string containing the full dataset name, +e.g. "pool/fs#bookmark". .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "snapshot (string)" +.It Ar dataset Pq string Must be a valid filesystem or volume. -.Ed -.It Em zfs.list.holds(snapshot) -Iterate through all user holds on the given snapshot. Each hold is returned +.El +.It Fn zfs.list.holds snapshot +Iterate through all user holds on the given snapshot. +Each hold is returned as a pair of the hold's tag and the timestamp (in seconds since the epoch) at which it was created. .Pp -snapshot (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "snapshot (string)" +.It Ar snapshot Pq string Must be a valid snapshot. -.Ed -.It Em zfs.list.properties(dataset) +.El +.It Fn zfs.list.properties dataset An alias for zfs.list.user_properties (see relevant entry). .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "snapshot (string)" +.It Ar dataset Pq string Must be a valid filesystem, snapshot, or volume. -.Ed -.It Em zfs.list.user_properties(dataset) -Iterate through all user properties for the given dataset. For each -step of the iteration, output the property name, its value, and its source. +.El +.It Fn zfs.list.user_properties dataset +Iterate through all user properties for the given dataset. +For each step of the iteration, output the property name, its value, +and its source. Throws a Lua error if the dataset is invalid. .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "snapshot (string)" +.It Ar dataset Pq string Must be a valid filesystem, snapshot, or volume. -.Ed -.It Em zfs.list.system_properties(dataset) +.El +.It Fn zfs.list.system_properties dataset Returns an array of strings, the names of the valid system (non-user defined) properties for the given dataset. Throws a Lua error if the dataset is invalid. .Pp -dataset (string) -.Bd -ragged -compact -offset "xxxx" +.Bl -tag -compact -width "snapshot (string)" +.It Ar dataset Pq string Must be a valid filesystem, snapshot or volume. -.Ed .El .El +.El +. .Sh EXAMPLES +. .Ss Example 1 The following channel program recursively destroys a filesystem and all its snapshots and children in a naive manner. @@ -579,6 +571,7 @@ function destroy_recursive(root) end destroy_recursive("pool/somefs") .Ed +. .Ss Example 2 A more verbose and robust version of the same channel program, which properly detects and reports errors, and also takes the dataset to destroy @@ -617,6 +610,7 @@ results["succeeded"] = succeeded results["failed"] = failed return results .Ed +. .Ss Example 3 The following function performs a forced promote operation by attempting to promote the given clone and destroying any conflicting snapshots. |