diff options
author | Richard Laager <rlaager@wiktel.com> | 2016-05-11 13:19:31 -0500 |
---|---|---|
committer | Brian Behlendorf <behlendorf1@llnl.gov> | 2016-05-16 12:26:31 -0700 |
commit | 8fd888baa7be971233a72331f2ae7bc15087a4c8 (patch) | |
tree | cec94ca6e96dc72b92042c2a0b6fe1eecb86ad25 /man | |
parent | 8e07f9a916c206833b94f047d834bc791661a3ed (diff) |
zfs.8 & zpool.8: Various documentation edits
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Diffstat (limited to 'man')
-rw-r--r-- | man/man8/zfs.8 | 135 | ||||
-rw-r--r-- | man/man8/zpool.8 | 8 |
2 files changed, 80 insertions, 63 deletions
diff --git a/man/man8/zfs.8 b/man/man8/zfs.8 index be5394df7..10e475a02 100644 --- a/man/man8/zfs.8 +++ b/man/man8/zfs.8 @@ -431,7 +431,7 @@ This property can also be referred to by its shortened column name, \fBavail\fR. .ad .sp .6 .RS 4n -For non-snapshots, the compression ratio achieved for the \fBused\fR space of this dataset, expressed as a multiplier. The \fBused\fR property includes descendant datasets, and, for clones, does not include the space shared with the origin snapshot. For snapshots, the \fBcompressratio\fR is the same as the \fBrefcompressratio\fR property. Compression can be turned on by running: \fBzfs set compression=on \fIdataset\fR\fR. The default value is \fBoff\fR. +For non-snapshots, the compression ratio achieved for the \fBused\fR space of this dataset, expressed as a multiplier. The \fBused\fR property includes descendant datasets, and, for clones, does not include the space shared with the origin snapshot. For snapshots, the \fBcompressratio\fR is the same as the \fBrefcompressratio\fR property. The \fBcompression\fR property controls whether compression is enabled on a dataset. .RE .sp @@ -456,7 +456,9 @@ The time this dataset was created. For snapshots, this property is a comma-separated list of filesystems or volumes which are clones of this snapshot. The clones' \fBorigin\fR property is this snapshot. If the \fBclones\fR property is not empty, then this -snapshot can not be destroyed (even with the \fB-r\fR or \fB-f\fR options). +snapshot can not be destroyed (even with the \fB-r\fR or \fB-f\fR options). The +roles of origin and clone can be swapped by promoting the clone with the +\fBzfs promote\fR command. .RE .sp @@ -598,7 +600,7 @@ The amount of space consumed by this dataset and all its descendents. This is th .sp When snapshots (see the "Snapshots" section) are created, their space is initially shared between the snapshot and the file system, and possibly with previous snapshots. As the file system changes, space that was previously shared becomes unique to the snapshot, and counted in the snapshot's space used. Additionally, deleting snapshots can increase the amount of space unique to (and used by) other snapshots. .sp -The amount of space used, available, or referenced does not take into account pending changes. Pending changes are generally accounted for within a few seconds. Committing a change to a disk using \fBfsync\fR(2) or \fBO_SYNC\fR does not necessarily guarantee that the space usage information is updated immediately. +The amount of space used, available, or referenced does not take into account pending changes. Pending changes are generally accounted for within a few seconds. Committing a change to a disk using \fBfsync\fR(2) or \fBO_SYNC\fR (see \fBopen\fR(2)) does not necessarily guarantee that the space usage information is updated immediately. .RE .sp @@ -787,12 +789,12 @@ The \fBaclinherit\fR property does not apply to Posix ACLs. .ne 2 .mk .na -\fB\fBacltype\fR=\fBnoacl\fR | \fBposixacl\fR \fR +\fB\fBacltype\fR=\fBoff\fR | \fBnoacl\fR | \fBposixacl\fR \fR .ad .sp .6 .RS 4n Controls whether ACLs are enabled and if so what type of ACL to use. When -a file system has the \fBacltype\fR property set to \fBnoacl\fR (the default) +a file system has the \fBacltype\fR property set to \fBoff\fR (the default) then ACLs are disabled. Setting the \fBacltype\fR property to \fBposixacl\fR indicates Posix ACLs should be used. Posix ACLs are specific to Linux and are not functional on other platforms. Posix ACLs are stored as an xattr and @@ -804,6 +806,8 @@ encouraged to set the \fBxattr=sa\fR property. This will result in the Posix ACL being stored more efficiently on disk. But as a consequence of this all new xattrs will only be accessible from ZFS implementations which support the \fBxattr=sa\fR property. See the \fBxattr\fR property for more details. +.sp +The value \fBnoacl\fR is an alias for \fBoff\fR. .RE .sp @@ -902,7 +906,9 @@ This property can also be referred to by its shortened column name .RS 4n Controls the number of copies of data stored for this dataset. These copies are in addition to any redundancy provided by the pool, for example, mirroring or RAID-Z. The copies are stored on different disks, if possible. The space used by multiple copies is charged to the associated file and dataset, changing the \fBused\fR property and counting against quotas and reservations. .sp -Changing this property only affects newly-written data. Therefore, set this property at file system creation time by using the \fB-o\fR \fBcopies=\fR\fIN\fR option. +Changing this property only affects newly-written data. +.sp +Remember that \fBZFS\fR will not import a pool with a missing top-level vdev. Do NOT create, for example, a two-disk, striped pool and set \fBcopies=\fR\fI2\fR on some datasets thinking you have setup redundancy for them. When one disk dies, you will not be able to import the pool and will have lost all of your data. .RE .sp @@ -1056,9 +1062,9 @@ a zone. This feature must be enabled to be used (see \fBzpool-features\fR(5)). .ad .sp .6 .RS 4n -Limits the amount of space consumed by the specified user. Similar to the \fBrefquota\fR property, the \fBuserquota\fR space calculation does not include space that is used by descendent datasets, such as snapshots and clones. User space consumption is identified by the \fBuserspace@\fR\fIuser\fR property. +Limits the amount of space consumed by the specified user. Similar to the \fBrefquota\fR property, the \fBuserquota\fR space calculation does not include space that is used by descendent datasets, such as snapshots and clones. User space consumption is identified by the \fBuserspace@\fR\fIuser\fR property. See the \fBzfs userspace\fR subcommand for more information. .sp -Enforcement of user quotas may be delayed by several seconds. This delay means that a user might exceed their quota before the system notices that they are over quota and begins to refuse additional writes with the \fBEDQUOT\fR error message . See the \fBzfs userspace\fR subcommand for more information. +Enforcement of user quotas may be delayed by several seconds. This delay means that a user might exceed their quota before the system notices that they are over quota and begins to refuse additional writes with the \fBEDQUOT\fR error message. .sp Unprivileged users can only access their own groups' space usage. The root user, or a user who has been granted the \fBuserquota\fR privilege with \fBzfs allow\fR, can get and set everyone's quota. .sp @@ -1189,7 +1195,9 @@ Limits the amount of space a dataset can consume. This property enforces a hard .RS 4n The minimum amount of space guaranteed to a dataset, not including its descendents. When the amount of space used is below this value, the dataset is treated as if it were taking up the amount of space specified by \fBrefreservation\fR. The \fBrefreservation\fR reservation is accounted for in the parent datasets' space used, and counts against the parent datasets' quotas and reservations. .sp -If \fBrefreservation\fR is set, a snapshot is only allowed if there is enough free pool space outside of this reservation to accommodate the current number of "referenced" bytes in the dataset. +If \fBrefreservation\fR is set, a snapshot is only allowed if there is enough free pool space outside of this reservation to accommodate the current number of \fBreferenced\fR bytes in the dataset (which are the bytes to be referenced by the snapshot). This is necessary to continue to provide the \fBrefreservation\fRguarantee to the dataset. +.sp +For volumes, see also \fBvolsize\fR. .sp This property can also be referred to by its shortened column name, \fBrefreserv\fR. .RE @@ -1326,6 +1334,8 @@ Provide a hint to ZFS about handling of synchronous requests in this dataset. If .sp .6 .RS 4n Controls whether the snapshots devices of zvol's are hidden or visible. The default value is \fBhidden\fR. +.sp +In this context, hidden does not refer to the concept of hiding files or directories by starting their name with a "." character. Even with \fBvisible\fR, the directory is still named \fB\&.zfs\fR. Instead, \fBhidden\fR means that the directory is not returned by \fBreaddir\fR(3), so it doesn't show up in directory listings done by any program, including \fBls\fR \fB-a\fR. It is still possible to chdir(2) into the directory, so \fBcd\fR \fB\&.zfs\fR works even with \fBhidden\fR. This unusual behavior is to protect against unwanted effects from applications recursing into the special \fB\&.zfs\fR directory. .RE .sp @@ -1367,7 +1377,7 @@ should only use this option when the risks are understood. .ad .sp .6 .RS 4n -The on-disk version of this file system, which is independent of the pool version. This property can only be set to later supported versions. See the \fBzfs upgrade\fR command. +The on-disk version of this file system, which is independent of the pool version. This property can only be set to later supported versions. The value \fBcurrent\fR automatically selects the latest supported version. See the \fBzfs upgrade\fR command. .RE .sp @@ -1378,11 +1388,11 @@ The on-disk version of this file system, which is independent of the pool versio .ad .sp .6 .RS 4n -For volumes, specifies the logical size of the volume. By default, creating a volume establishes a reservation of equal size. For storage pools with a version number of 9 or higher, a \fBrefreservation\fR is set instead. Any changes to \fBvolsize\fR are reflected in an equivalent change to the reservation (or \fBrefreservation\fR). The \fBvolsize\fR can only be set to a multiple of \fBvolblocksize\fR, and cannot be zero. +For volumes, specifies the logical size of the volume. By default, creating a volume establishes a \fBrefreservation\fR equal to the volume size plus the metadata required for a fully-written volume. (For pool version 8 or lower, a \fBreservation\fR is set instead.) Any changes to \fBvolsize\fR are reflected in an equivalent change to the \fBrefreservation\fR. The \fBvolsize\fR can only be set to a multiple of \fBvolblocksize\fR, and cannot be zero. .sp -The reservation is kept equal to the volume's logical size to prevent unexpected behavior for consumers. Without the reservation, the volume could run out of space, resulting in undefined behavior or data corruption, depending on how the volume is used. These effects can also occur when the volume size is changed while it is in use (particularly when shrinking the size). Extreme care should be used when adjusting the volume size. +Without the reservation, the volume could run out of space, resulting in undefined behavior or data corruption, depending on how the volume is used. These effects can also occur when the volume size is changed while it is in use (particularly when shrinking the size). Extreme care should be used when adjusting the volume size. .sp -Though not recommended, a "sparse volume" (also known as "thin provisioning") can be created by specifying the \fB-s\fR option to the \fBzfs create -V\fR command, or by changing the reservation after the volume has been created. A "sparse volume" is a volume where the reservation is less then the volume size. Consequently, writes to a sparse volume can fail with \fBENOSPC\fR when the pool is low on space. For a sparse volume, changes to \fBvolsize\fR are not reflected in the reservation. +A "sparse volume" (also known as "thin provisioning") can be created by specifying the \fB-s\fR option to the \fBzfs create -V\fR command, or by removing (or changing) the \fBrefreservation\fR after the volume has been created. A "sparse volume" is a volume where the \fBrefreservation\fR is unset or less then the volume size. Consequently, writes to a sparse volume can fail with \fBENOSPC\fR when the pool is low on space. For a sparse volume, changes to \fBvolsize\fR are not reflected in the reservation. .RE .sp @@ -1468,7 +1478,16 @@ The \fBmixed\fR value for the \fBcasesensitivity\fR property indicates that the .ad .sp .6 .RS 4n -Indicates whether the file system should perform a \fBunicode\fR normalization of file names whenever two file names are compared, and which normalization algorithm should be used. File names are always stored unmodified, names are normalized as part of any comparison process. If this property is set to a value other than \fBnone\fR, and the \fButf8only\fR property was left unspecified, the \fButf8only\fR property is automatically set to \fBon\fR. The default value of the \fBnormalization\fR property is \fBnone\fR. This property cannot be changed after the file system is created. +Indicates whether the file system should perform a Unicode normalization of file names whenever two file names are compared, and which normalization algorithm should be used. +.sp +If this property is set to a value other than \fBnone\fR (the default), and the \fButf8only\fR property was left unspecified, the \fButf8only\fR property is automatically set to \fBon\fR. See the cautionary note in the \fButf8only\fR section before modifying \fBnormalization\fR. +.sp +File names are always stored unmodified; names are normalized as part of any comparison process. Thus, \fBformC\fR and \fBformD\fR are equivalent, as are \fBformKC\fR and \fBformKD\fR. Given that, only \fBformD\fR and \fBformKD\fR make sense, as they are slightly faster because they avoid the additional canonical composition step. +.\" unicode.org says it's possible to quickly detect if a string is already in a given form. Since most text (basically everything but OS X) is already in NFC, this means formC could potentially be made faster. But the additional complexity probably isn't worth the likely undetectable in practice speed improvement. +.sp +The practical impact of this property is: \fBnone\fR (like traditional filesystems) allows a directory to contain two files that appear (to humans) to have the same name. The other options solve this problem, for different definitions of "the same". If you need to solve this problem and are not sure what to choose,\fBformD\fR. +.sp +This property cannot be changed after the file system is created. .RE .sp @@ -1479,12 +1498,18 @@ Indicates whether the file system should perform a \fBunicode\fR normalization o .ad .sp .6 .RS 4n -Indicates whether the file system should reject file names that include characters that are not present in the \fBUTF-8\fR character code set. If this property is explicitly set to \fBoff\fR, the normalization property must either not be explicitly set or be set to \fBnone\fR. The default value for the \fButf8only\fR property is \fBoff\fR. This property cannot be changed after the file system is created. +Indicates whether the file system should reject file names that include characters that are not present in the \fBUTF-8\fR character set. If this property is explicitly set to \fBoff\fR, the \fBnormalization\fR property must either not be explicitly set or be set to \fBnone\fR. The default value for the \fButf8only\fR property is \fBoff\fR. +.sp +Note that forcing the use of \fBUTF-8\fR filenames may cause pain for users. For example, extracting files from an archive will fail if the filenames within the archive are encoded in another character set. +.sp +If you are thinking of setting this (to \fBon\fR), you probably want to set \fBnormalization\fR=\fBformD\fR which will set this property to \fBon\fR implicitly. +.sp +This property cannot be changed after the file system is created. .RE .sp .LP -The \fBcasesensitivity\fR, \fBnormalization\fR, and \fButf8only\fR properties are also new permissions that can be assigned to non-privileged users by using the \fBZFS\fR delegated administration feature. +The \fBcasesensitivity\fR, \fBnormalization\fR, and \fButf8only\fR properties are also permissions that can be assigned to non-privileged users by using the \fBZFS\fR delegated administration feature. .RE .sp @@ -1585,7 +1610,7 @@ with the \fBzfs create\fR command set up and enable the swap area using the \fBZFS\fR file system. A \fBZFS\fR swap file configuration is not supported. .SH SUBCOMMANDS .LP -All subcommands that modify state are logged persistently to the pool in their original form. +All subcommands that modify state are logged persistently to the pool in their original form. The log can be viewed with \fBzpool history\fR. .sp .ne 2 .mk @@ -1605,7 +1630,7 @@ Displays a help message. .ad .sp .6 .RS 4n -Creates a new \fBZFS\fR file system. The file system is automatically mounted according to the \fBmountpoint\fR property inherited from the parent. +Creates a new \fBZFS\fR file system. The file system is automatically mounted according to the \fBmountpoint\fR and \fBcanmount\fR properties. .sp .ne 2 .mk @@ -1614,7 +1639,7 @@ Creates a new \fBZFS\fR file system. The file system is automatically mounted ac .ad .sp .6 .RS 4n -Creates all the non-existing parent datasets. Datasets created in this manner are automatically mounted according to the \fBmountpoint\fR property inherited from their parent. Any property specified on the command line using the \fB-o\fR option is ignored. If the target filesystem already exists, the operation completes successfully. +Creates all the non-existing parent datasets. Datasets created in this manner inherit their properties; any property specified on the command line using the \fB-o\fR option applies only to the final child file system. If the target filesystem already exists, the operation completes successfully and no properties are changed. .RE .sp @@ -1638,7 +1663,7 @@ Sets the specified property as if the command \fBzfs set\fR \fIproperty\fR=\fIva .ad .sp .6 .RS 4n -Creates a volume of the given size. The volume is exported as a block device in \fB/dev/zvol/\fR\fIpath\fR, where \fIpath\fR is the name of the volume in the \fBZFS\fR namespace. The size represents the logical size as exported by the device. By default, a reservation of equal size is created. +Creates a volume of the given size. The volume is exported as a block device in \fB/dev/zvol/\fR\fIpath\fR, where \fIpath\fR is the name of the volume in the \fBZFS\fR namespace. The size represents the logical size as exported by the device. By default, a \fBrefreservation\fR is created. .sp \fIsize\fR is automatically rounded up to the nearest 128KiB to ensure that the volume has an integral number of blocks regardless of \fIblocksize\fR. .sp @@ -1649,7 +1674,7 @@ Creates a volume of the given size. The volume is exported as a block device in .ad .sp .6 .RS 4n -Creates all the non-existing parent datasets. Datasets created in this manner are automatically mounted according to the \fBmountpoint\fR property inherited from their parent. Any property specified on the command line using the \fB-o\fR option is ignored. If the target filesystem already exists, the operation completes successfully. +Creates all the non-existing parent datasets as file systems. Datasets created in this manner inherit their properties; any property specified on the command line using the \fB-o\fR option applies only to the final child volume. If the target volume already exists, the operation completes successfully and no properties are changed. .RE .sp @@ -1660,7 +1685,7 @@ Creates all the non-existing parent datasets. Datasets created in this manner ar .ad .sp .6 .RS 4n -Creates a sparse volume with no reservation. See \fBvolsize\fR in the Native Properties section for more information about sparse volumes. +Creates a sparse volume by omitting the automatic creation of a \fBrefreservation\fR. See \fBvolsize\fR in the Native Properties section for more information about sparse volumes. If this option is specified in conjunction with \fB-o\fR \fBrefreservation\fR, the \fBrefreservation\fR will be honored; this allows for a partial reservation on a sparse volume. .RE .sp @@ -1672,6 +1697,8 @@ Creates a sparse volume with no reservation. See \fBvolsize\fR in the Native Pro .sp .6 .RS 4n Sets the specified property as if the \fBzfs set\fR \fIproperty\fR=\fIvalue\fR command was invoked at the same time the dataset was created. Any editable \fBZFS\fR property can also be set at creation time. Multiple \fB-o\fR options can be specified. An error results if the same property is specified in multiple \fB-o\fR options. +.sp +If \fB-o\fR \fBvolsize\fR is provided, the resulting behavior is undefined; it conflicts with the -V option, which is required in this mode. .RE .sp @@ -1726,7 +1753,7 @@ Recursively destroy all dependents, including cloned file systems outside the ta .ad .sp .6 .RS 4n -Force an unmount of any file systems using the \fBunmount -f\fR command. This option has no effect on non-file systems or unmounted file systems. +Force an unmount of any file systems using the \fBzfs unmount -f\fR command. This option has no effect on non-file systems or unmounted file systems. .RE .sp @@ -1762,7 +1789,7 @@ Print verbose information about the deleted data. .RE .sp -Extreme care should be taken when applying either the \fB-r\fR or the \fB-R\fR options, as they can destroy large portions of a pool and cause unexpected behavior for mounted file systems in use. +Extreme care should be taken when applying either the \fB-r\fR or the \fB-R\fR options, as they can destroy large portions of a pool. .RE .sp @@ -1773,9 +1800,7 @@ Extreme care should be taken when applying either the \fB-r\fR or the \fB-R\fR o .ad .sp .6 .RS 4n -The given snapshots are destroyed immediately if and only if the \fBzfs destroy\fR command without the \fB-d\fR option would have destroyed it. Such immediate destruction would occur, for example, if the snapshot had no clones and the user-initiated reference count were zero. -.sp -If a snapshot does not qualify for immediate destruction, it is marked for deferred destruction. In this state, it exists as a usable, visible snapshot until both of the preconditions listed above are met, at which point it is destroyed. +The specified snapshots are destroyed immediately if they have no clones and the user-initiated reference count is zero (i.e. there are no holds set with \fBzfs hold\fR). If these conditions are not met, this command returns an error, unless \fB-d\fR is supplied. .sp An inclusive range of snapshots may be specified by separating the first and last snapshots with a percent sign. @@ -1796,7 +1821,7 @@ comma-separated list to identify multiple snapshots. .ad .sp .6 .RS 4n -Defer snapshot deletion. +If the snapshot does not qualify for immediate destruction, rather than returning an error, it is marked for deferred destruction. In this state, it exists as a usable, visible snapshot until both of the preconditions listed above are met, at which point it is destroyed. .RE .sp @@ -1902,7 +1927,7 @@ Recursively create snapshots of all descendent datasets. .ad .sp .6 .RS 4n -Sets the specified property; see \fBzfs create\fR for details. +Sets the specified property; see \fBzfs set\fR for details. .RE .RE @@ -1948,7 +1973,7 @@ Recursively destroy any more recent snapshots and bookmarks, as well as any clon .ad .sp .6 .RS 4n -Used with the \fB-R\fR option to force an unmount of any clone file systems that are to be destroyed. +Used with the \fB-R\fR option to force an unmount (see \fBzfs unmount -f\fR) of any clone file systems that are to be destroyed. .RE .RE @@ -1970,7 +1995,7 @@ Creates a clone of the given snapshot. See the "Clones" section for details. The .ad .sp .6 .RS 4n -Creates all the non-existing parent datasets. Datasets created in this manner are automatically mounted according to the \fBmountpoint\fR property inherited from their parent. If the target filesystem or volume already exists, the operation completes successfully. +Creates all the non-existing parent datasets; see \fBzfs create\fR for details. .RE .sp @@ -1981,7 +2006,7 @@ Creates all the non-existing parent datasets. Datasets created in this manner ar .ad .sp .6 .RS 4n -Sets the specified property; see \fBzfs create\fR for details. +Sets the specified property; see \fBzfs set\fR for details. .RE .RE @@ -1996,7 +2021,7 @@ Sets the specified property; see \fBzfs create\fR for details. .RS 4n Promotes a clone file system to no longer be dependent on its "origin" snapshot. This makes it possible to destroy the file system that the clone was created from. The clone parent-child dependency relationship is reversed, so that the origin file system becomes a clone of the specified file system. .sp -The snapshot that was cloned, and any snapshots previous to this snapshot, are now owned by the promoted clone. The space they use moves from the origin file system to the promoted clone, so enough space must be available to accommodate these snapshots. No new space is consumed by this operation, but the space accounting is adjusted. The promoted clone must not have any conflicting snapshot names of its own. The \fBrename\fR subcommand can be used to rename any conflicting snapshots. +The snapshot that was cloned, and any snapshots previous to this snapshot, are now owned by the promoted clone. The space they use moves from the origin file system to the promoted clone, so enough space must be available to accommodate these snapshots. No new space is consumed by this operation, but the space accounting is adjusted. The promoted clone must not have any conflicting snapshot names of its own. The \fBzfs rename\fR command can be used to rename any conflicting snapshots. .RE .sp @@ -2020,7 +2045,7 @@ Renames the given dataset. The new target can be located anywhere in the \fBZFS\ .ad .sp .6 .RS 4n -Creates all the nonexistent parent datasets. Datasets created in this manner are automatically mounted according to the \fBmountpoint\fR property inherited from their parent. +Creates all the nonexistent parent datasets; see \fBzfs create\fR for details. .RE .sp @@ -2054,7 +2079,7 @@ Recursively rename the snapshots of all descendent datasets. Snapshots are the o .ad .sp .6 .RS 4n -Lists the property information for the given datasets in tabular form. If a mount point is specified, it can be an absolute pathname or a relative pathname as long as it contains a slash (e.g. \fBzfs list ./\fR). By default, all file systems and volumes are displayed. Snapshots are displayed if the \fBlistsnaps\fR property is \fBon\fR (the default is \fBoff\fR). When listing hundreds or thousands of snapshots performance can be improved by restricting the output to only the name. In that case, it is recommended to use \fB-o name -s name\fR. The following fields are displayed by default, \fBname,used,available,referenced,mountpoint\fR +Lists the property information for the given datasets in tabular form. If a mount point is specified, it can be an absolute pathname or a relative pathname as long as it contains a slash (e.g. \fBzfs list ./\fR). By default, all file systems and volumes are displayed. Snapshots are displayed if the pool's \fBlistsnapshots\fR property is \fBon\fR (the default is \fBoff\fR). When listing hundreds or thousands of snapshots performance can be improved by restricting the output to only the name. In that case, it is recommended to use \fB-o name -s name\fR. The following fields are displayed by default: \fBname, used, available, referenced, mountpoint\fR .sp .ne 2 .mk @@ -2447,7 +2472,7 @@ Print numeric ID instead of user/group name. .ad .sp .6 .RS 4n -Do not print headers, use tab-delimited output. +Display output in a form more easily parsed by scripts. Any headers are omitted, and fields are explicitly separated by a single tab instead of an arbitrary amount of space. .RE .sp @@ -2568,7 +2593,7 @@ Displays all \fBZFS\fR file systems currently mounted. .ad .sp .6 .RS 4n -Mounts \fBZFS\fR file systems. Invoked automatically as part of the boot process. +Mounts \fBZFS\fR file systems. This is invoked automatically as part of the boot process. .sp .ne 2 .mk @@ -2605,7 +2630,7 @@ On Linux, this is the default for \fBmount\fR(8). In other words, \fBzfs mount - .ad .sp .6 .RS 4n -Report mount progress. +Report mount progress. This is intended for use with \fBzfs mount -a\fR on a system with a significant number of filesystems. .RE .sp @@ -2668,7 +2693,7 @@ Unmount all available \fBZFS\fR file systems. Invoked automatically as part of t .ne 2 .mk .na -\fB\fIfilesystem\fR|\fImountpoint\fR\fR +\fIfilesystem\fR|\fImountpoint\fR .ad .sp .6 .RS 4n @@ -2769,7 +2794,7 @@ See \fBzpool-features\fR(5) for details on ZFS feature flags and the .ad .sp .6 .RS 4n -Creates a stream representation of the second \fIsnapshot\fR, which is written to standard output. The output can be redirected to a file or to a different system (for example, using \fBssh\fR(1). By default, a full stream is generated. +Creates a stream representation of the (second, if \fB-i\fR is specified) \fIsnapshot\fR, which is written to standard output. The output can be redirected to a file or to a pipe (for example, using \fBssh\fR(1) to send it to a different system with \fBzfs receive\fR). By default, a full stream is generated; specifying \fB-i\fR or \fB-I\fR changes this behavior. .sp .ne 2 .mk @@ -3020,7 +3045,7 @@ Discard all but the last element of the sent snapshot's file system name, using .ad .sp .6 .RS 4n -File system that is associated with the received stream is not mounted. +Do not mount the file system that is associated with the received stream. .RE .sp @@ -3129,7 +3154,7 @@ Specifies where the permissions are delegated. If neither of the \fB-ld\fR optio .sp .LP -Permissions are generally the ability to use a \fBzfs\fR subcommand or change a \fBZFS\fR property. The following permissions are available: +Permissions are generally the ability to use a \fBzfs\fR subcommand or change a property. The following permissions are available: .sp .in +2 .nf @@ -3235,11 +3260,7 @@ Defines or adds permissions to a permission set. The set can be used by other \f .ad .br .na -\fB\fBzfs unallow\fR [\fB-r\fR] \fB-c\fR [\fIperm\fR|@\fIsetname\fR[,...]]\fR -.ad -.br -.na -\fB\fIfilesystem\fR|\fIvolume\fR\fR +\fB\fBzfs unallow\fR [\fB-r\fR] \fB-c\fR [\fIperm\fR|@\fIsetname\fR[,...]]\fR \fB\fIfilesystem\fR|\fIvolume\fR\fR .ad .sp .6 .RS 4n @@ -3261,11 +3282,7 @@ Recursively remove the permissions from this file system and all descendents. .ne 2 .mk .na -\fB\fBzfs unallow\fR [\fB-r\fR] \fB-s\fR @\fIsetname\fR [\fIperm\fR|@\fIsetname\fR[,...]]\fR -.ad -.br -.na -\fB\fIfilesystem\fR|\fIvolume\fR\fR +\fB\fBzfs unallow\fR [\fB-r\fR] \fB-s\fR @\fIsetname\fR [\fIperm\fR|@\fIsetname\fR[,...]]\fR \fB\fIfilesystem\fR|\fIvolume\fR\fR .ad .sp .6 .RS 4n @@ -3328,8 +3345,6 @@ Lists the holds that are set on the named descendent snapshots, in addition to l .RS 4n Removes a single reference, named with the \fItag\fR argument, from the specified snapshot or snapshots. The tag must already exist for each snapshot. .sp -If a hold exists on a snapshot, attempts to destroy that snapshot by using the \fBzfs destroy\fR command return \fBEBUSY\fR. -.sp .ne 2 .mk .na @@ -3428,12 +3443,12 @@ The following commands create a file system named \fBpool/home\fR and a file sys \fBExample 2 \fRCreating a ZFS Snapshot .sp .LP -The following command creates a snapshot named \fByesterday\fR. This snapshot is mounted on demand in the \fB\&.zfs/snapshot\fR directory at the root of the \fBpool/home/bob\fR file system. +The following command creates a snapshot named \fBbackup\fR. This snapshot is mounted on demand in the \fB\&.zfs/snapshot\fR directory at the root of the \fBpool/home/bob\fR file system. .sp .in +2 .nf -# \fBzfs snapshot pool/home/bob@yesterday\fR +# \fBzfs snapshot pool/home/bob@backup\fR .fi .in -2 .sp @@ -3442,13 +3457,13 @@ The following command creates a snapshot named \fByesterday\fR. This snapshot is \fBExample 3 \fRCreating and Destroying Multiple Snapshots .sp .LP -The following command creates snapshots named \fByesterday\fR of \fBpool/home\fR and all of its descendent file systems. Each snapshot is mounted on demand in the \fB\&.zfs/snapshot\fR directory at the root of its file system. The second command destroys the newly created snapshots. +The following command creates snapshots named \fBbackup\fR of \fBpool/home\fR and all of its descendent file systems. Each snapshot is mounted on demand in the \fB\&.zfs/snapshot\fR directory at the root of its file system. The second command destroys the newly created snapshots. .sp .in +2 .nf -# \fBzfs snapshot -r pool/home@yesterday\fR -# \fBzfs destroy -r pool/home@yesterday\fR +# \fBzfs snapshot -r pool/home@backup\fR +# \fBzfs destroy -r pool/home@backup\fR .fi .in -2 .sp @@ -3472,7 +3487,7 @@ The following command disables the \fBcompression\fR property for all file syste \fBExample 5 \fRListing ZFS Datasets .sp .LP -The following command lists all active file systems and volumes in the system. Snapshots are displayed if the \fBlistsnaps\fR property is \fBon\fR. The default is \fBoff\fR. See \fBzpool\fR(8) for more information on pool properties. +The following command lists all active file systems and volumes in the system. Snapshots are displayed if the pool's \fBlistsnapshots\fR property is \fBon\fR (the default is \fBoff\fR). See \fBzpool\fR(8) for more information on pool properties. .sp .in +2 diff --git a/man/man8/zpool.8 b/man/man8/zpool.8 index b2a5d6cc4..841797569 100644 --- a/man/man8/zpool.8 +++ b/man/man8/zpool.8 @@ -614,11 +614,11 @@ The following property can be set at creation time: .ne 2 .mk .na -\fB\fBashift\fR\fR +\fB\fBashift\fR=\fIashift\fR\fR .ad .sp .6 .RS 4n -Pool sector size exponent, to the power of 2 (internally referred to as "ashift"). I/O operations will be aligned to the specified size boundaries. Additionally, the minimum (disk) write size will be set to the specified size, so this represents a space vs. performance trade-off. The typical case for setting this property is when performance is important and the underlying disks use 4KiB sectors but report 512B sectors to the OS (for compatibility reasons); in that case, set \fBashift=12\fR (which is 1<<12 = 4096). +Pool sector size exponent, to the power of 2 (internally referred to as "ashift"). Values from 9 to 13, inclusive, are valid; also, the special value 0 (the default) means to auto-detect using the kernel's block layer and a ZFS internal exception list. I/O operations will be aligned to the specified size boundaries. Additionally, the minimum (disk) write size will be set to the specified size, so this represents a space vs. performance trade-off. The typical case for setting this property is when performance is important and the underlying disks use 4KiB sectors but report 512B sectors to the OS (for compatibility reasons); in that case, set \fBashift=12\fR (which is 1<<12 = 4096). .LP For optimal performance, the pool sector size should be greater than or equal to the sector size of the underlying disks. Since the property cannot be changed after pool creation, if in a given pool, you \fIever\fR want to use drives that \fIreport\fR 4KiB sectors, you must set \fBashift=12\fR at pool creation time. .LP @@ -799,11 +799,13 @@ details on feature states. .ne 2 .mk .na -\fB\fBlistsnaps\fR=on | off\fR +\fB\fBlistsnapshots\fR=on | off\fR .ad .sp .6 .RS 4n Controls whether information about snapshots associated with this pool is output when "\fBzfs list\fR" is run without the \fB-t\fR option. The default value is "off". +.sp +This property can also be referred to by its shortened name, \fBlistsnaps\fR. .RE .sp |