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-.TH zpool 8 "8 Apr 2011" "SunOS 5.11" "System Administration Commands"
+.TH zpool 8 "8 Apr 2011" "ZFS pool 28, filesystem 5" "System Administration Commands"
.SH NAME
zpool \- configures ZFS storage pools
.SH SYNOPSIS
.sp
.LP
-Spares can be shared across multiple pools, and can be added with the "\fBzpool add\fR" command and removed with the "\fBzpool remove\fR" command. Once a spare replacement is initiated, a new "spare" \fBvdev\fR is created within the configuration that will remain there until the original device is replaced. At this point, the hot spare becomes available again if another device fails.
+Spares can be shared across multiple pools, and can be added with the "\fBzpool add\fR" command and removed with the "\fBzpool remove\fR" command. Once a spare replacement is initiated, a new "spare" \fBvdev\fR is created within the configuration that will remain there until the original device is replaced. At this point, the hot spare becomes available again.
.sp
.LP
If a pool has a shared spare that is currently being used, the pool can not be exported since other pools may use this shared spare, which may lead to potential data corruption.
.sp
.LP
These space usage properties report actual physical space available to the storage pool. The physical space can be different from the total amount of space that any contained datasets can actually use. The amount of space used in a \fBraidz\fR configuration depends on the characteristics of the data being written. In addition, \fBZFS\fR reserves some space for internal accounting that the \fBzfs\fR(8) command takes into account, but the \fBzpool\fR command does not. For non-full pools of a reasonable size, these effects should be invisible. For small pools, or pools that are close to being completely full, these discrepancies may become more noticeable.
+
+.sp
+.LP
+The following property can be set at creation time:
+.sp
+.ne 2
+.mk
+.na
+\fB\fBashift\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).
+.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.
+.RE
+
.sp
.LP
The following property can be set at creation time and import time:
.ad
.sp .6
.RS 4n
-Alternate root directory. If set, this directory is prepended to any mount points within the pool. This can be used when examining an unknown pool where the mount points cannot be trusted, or in an alternate boot environment, where the typical paths are not valid. \fBaltroot\fR is not a persistent property. It is valid only while the system is up. Setting \fBaltroot\fR defaults to using \fBcachefile\fR=none, though this may be overridden using an explicit setting.
+Alternate root directory. If set, this directory is prepended to any mount points within the pool. This can be used when examining an unknown pool where the mount points cannot be trusted, or in an alternate boot environment, where the typical paths are not valid. \fBaltroot\fR is not a persistent property. It is valid only while the system is up. Setting \fBaltroot\fR defaults to using \fBcachefile\fR=none, though this may be overridden using an explicit setting.
.RE
.sp
\fBExample 5 \fRAdding a Mirror to a ZFS Storage Pool
.sp
.LP
-The following command adds two mirrored disks to the pool "\fItank\fR", assuming the pool is already made up of two-way mirrors. The additional space is immediately available to any datasets within the pool.
+The following command adds two mirrored disks to the pool \fItank\fR, assuming the pool is already made up of two-way mirrors. The additional space is immediately available to any datasets within the pool.
.sp
.in +2
\fBExample 7 \fRDestroying a ZFS Storage Pool
.sp
.LP
-The following command destroys the pool "\fItank\fR" and any datasets contained within.
+The following command destroys the pool \fItank\fR and any datasets contained within.
.sp
.in +2
\fBExample 9 \fRImporting a ZFS Storage Pool
.sp
.LP
-The following command displays available pools, and then imports the pool "tank" for use on the system.
+The following command displays available pools, and then imports the pool \fItank\fR for use on the system.
.sp
.LP
.in +2
.nf
# \fBzpool upgrade -a\fR
-This system is currently running ZFS version 2.
+This system is currently running ZFS pool version 28.
.fi
.in -2
.sp
.sp
.LP
-Once the data has been resilvered, the spare is automatically removed and is made available should another device fails. The hot spare can be permanently removed from the pool using the following command:
+Once the data has been resilvered, the spare is automatically removed and is made available for use should another device fails. The hot spare can be permanently removed from the pool using the following command:
.sp
.in +2
Invalid command line options were specified.
.RE
-.SH ATTRIBUTES
-.sp
-.LP
-See \fBattributes\fR(5) for descriptions of the following attributes:
-.sp
-
-.sp
-.TS
-tab(\a) box;
-cw(2.75i) |cw(2.75i)
-lw(2.75i) |lw(2.75i)
-.
-ATTRIBUTE TYPE\aATTRIBUTE VALUE
-_
-Availability\aSUNWzfsu
-_
-Interface Stability\aEvolving
-.TE
-
.SH SEE ALSO
.sp
.LP
-\fBzfs\fR(8), \fBattributes\fR(5)
+\fBzfs\fR(8)
git://git.camperquake.de / zfs.git / blobdiff