special A device dedicated solely for allocating various kinds of internal If more than one dedup device is specified, then allocations are The redundancy of thisĭevice should match the redundancy of the other normal devices in the dedup A device dedicated solely for deduplication tables. However, raidz vdev types are not supported for the intent log. Then writes are load-balanced between devices. If more than one log device is specified, spare A pseudo-vdev which keeps track of available hot spares for a pool. spares The number of distributed hot spares. Useful as a cross-check when listingĪ large number of devices. children The expected number of children. Improve the compression ratio, and speed up resilvering at theĮxpense of total usable capacity. data The number of data devices per redundancy group. More of the following optional arguments to the draid draid A non-default dRAID configuration can be specified by appending one or P parity level, and S distributed hot spares can hold approximately (N-S)*(D/(D+P))*X bytes and can withstand Pĭevices failing without losing data. Of size X, D data disks per redundancy group, Like raidz, a dRAID can have single-, double-, orĪnd draid3 types can be used to specify the parity Performance is similar to raidz since for any read allĭelivered random IOPS can be reasonably approximated as To also add a mirrored special vdev to store those Pool will hold a significant amount of small blocks, it is recommended Property is increased to account for the allocation size. Using compression, this relatively large allocation size can reduce theĮffective compression ratio. This fixed stripe width significantly effects both usable capacity andĭ=8 and 4 KiB disk sectors the minimum allocation size is 32 KiB. (padding as necessary with zeros) to allow fully sequential resilvering. Unlike raidz, dRAID uses a fixed stripe width These groupsĪre distributed over all of the children in order to fully utilize the AĭRAID vdev is constructed from multiple internal raidz groups, each withĭ data devices and P parity devices. The recommended number is between 3 and 9 to help increaseĭraid3 A variant of raidz that provides integrated distributed hot spares whichĪllows for faster resilvering while retaining the benefits of raidz. Number of devices in a raidz group is one more than the number of parityĭisks. The raidz vdev type is an alias forĪ raidz group with N disks of size X with P parityĭisks can hold approximately (N-P)*X bytes and can withstand P devices failing without losing data. Raidz3 vdev type specifies a triple-parity raidz Vdev type specifies a double-parity raidz group and the Type specifies a single-parity raidz group the raidz2 Meaning that the raidz group can sustain one, two, or three failures, Data and parity is striped acrossĪ raidz group can have single, double, or triple parity, Raidz3 A variation on RAID-5 that allows for better distribution of parity andĮliminates the RAID-5 "write hole" (in which data and parityīecome inconsistent after a power loss). N disks of size X can hold X bytes and can withstand N-1ĭevices failing without losing data. Data is replicated in an identicalįashion across all components of a mirror. It is designed primarily for experimental purposes, as theįault tolerance of a file is only as good as the file system on which it The use of files as a backing store is stronglyĭiscouraged. For example,Īutomatically labels the disk, if necessary. A whole disk can be specified by omitting Or it can be a shorthand name (the relative portion of the path under ZFSĬan use individual slices or partitions, though the recommended mode of The following virtual devices are supported: disk A block device, typically located under /dev. Overview of ZFS storage pools DESCRIPTION VirtualĪ "virtual device" describes a single device or aĬollection of devices organized according to certain performance and faultĬharacteristics.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |