plucky (7) vdevprops.7.gz

NAME

     vdevprops — native and user-defined properties of ZFS vdevs

DESCRIPTION

     Properties are divided into two types, native properties and user-defined (or "user") properties.  Native
     properties either export internal statistics or control ZFS behavior.  In addition, native properties are
     either editable or read-only.  User properties have no effect on ZFS behavior, but you can use them to
     annotate vdevs in a way that is meaningful in your environment.  For more information about user
     properties, see the User Properties section, below.

   Native Properties
     Every vdev has a set of properties that export statistics about the vdev as well as control various
     behaviors.  Properties are not inherited from top-level vdevs, with the exception of checksum_n,
     checksum_t, io_n, io_t, slow_io_n, and slow_io_t.

     The values of numeric properties can be specified using human-readable suffixes (for example, k, KB, M, Gb,
     and so forth, up to Z for zettabyte).  The following are all valid (and equal) specifications: 1536M, 1.5g,
     1.50GB.

     The values of non-numeric properties are case sensitive and must be lowercase.

     The following native properties consist of read-only statistics about the vdev.  These properties can not
     be changed.

     capacity       Percentage of vdev space used

     state          state of this vdev such as online, faulted, or offline

     guid           globally unique id of this vdev

     asize          The allocable size of this vdev

     psize          The physical size of this vdev

     ashift         The physical sector size of this vdev expressed as the power of two

     size           The total size of this vdev

     free           The amount of remaining free space on this vdev

     allocated      The amount of allocated space on this vdev

     expandsize     How much this vdev can expand by

     fragmentation  Percent of fragmentation in this vdev

     parity         The level of parity for this vdev

     devid          The device id for this vdev

     physpath       The physical path to the device

     encpath        The enclosure path to the device

     fru            Field Replacable Unit, usually a model number

     parent         Parent of this vdev

     children       Comma separated list of children of this vdev

     numchildren    The number of children belonging to this vdev

     read_errors, write_errors, checksum_errors, initialize_errors
                    The number of errors of each type encountered by this vdev

     null_ops, read_ops, write_ops, free_ops, claim_ops, trim_ops
                    The number of I/O operations of each type performed by this vdev

     null_bytes, read_bytes, write_bytes, free_bytes, claim_bytes, trim_bytes
                    The cumulative size of all operations of each type performed by this vdev

     removing       If this device is currently being removed from the pool

     The following native properties can be used to change the behavior of a vdev.

     checksum_n, checksum_t, io_n, io_t, slow_io_n, slow_io_t
                 Tune the fault management daemon by specifying checksum/io thresholds of <N> errors in <T>
                 seconds, respectively.  These properties can be set on leaf and top-level vdevs.  When the
                 property is set on the leaf and top-level vdev, the value of the leaf vdev will be used.  If
                 the property is only set on the top-level vdev, this value will be used.  The value of these
                 properties do not persist across vdev replacement.  For this reason, it is advisable to set the
                 property on the top-level vdev - not on the leaf vdev itself.  The default values for OpenZFS
                 on Linux are 10 errors in 600 seconds.  For OpenZFS on FreeBSD defaults see zfsd(8).

     comment     A text comment up to 8192 characters long

     bootsize    The amount of space to reserve for the EFI system partition

     failfast    If this device should propage BIO errors back to ZFS, used to disable failfast.

     path        The path to the device for this vdev

     allocating  If this device should perform new allocations, used to disable a device when it is scheduled
                 for later removal.  See zpool-remove(8).

   User Properties
     In addition to the standard native properties, ZFS supports arbitrary user properties.  User properties
     have no effect on ZFS behavior, but applications or administrators can use them to annotate vdevs.

     User property names must contain a colon (":") character to distinguish them from native properties.  They
     may contain lowercase letters, numbers, and the following punctuation characters: colon (":"), dash ("-"),
     period ("."), and underscore ("_").  The expected convention is that the property name is divided into two
     portions such as module:property, but this namespace is not enforced by ZFS.  User property names can be at
     most 256 characters, and cannot begin with a dash ("-").

     When making programmatic use of user properties, it is strongly suggested to use a reversed DNS domain name
     for the module component of property names to reduce the chance that two independently-developed packages
     use the same property name for different purposes.

     The values of user properties are arbitrary strings and are never validated.  Use the zpool set command
     with a blank value to clear a user property.  Property values are limited to 8192 bytes.

SEE ALSO

     zpoolprops(7), zpool-set(8)