diff options
Diffstat (limited to 'usr/src/man/man1m/zpool.1m')
| -rw-r--r-- | usr/src/man/man1m/zpool.1m | 46 |
1 files changed, 45 insertions, 1 deletions
diff --git a/usr/src/man/man1m/zpool.1m b/usr/src/man/man1m/zpool.1m index 70d3dc29d9..14e361a442 100644 --- a/usr/src/man/man1m/zpool.1m +++ b/usr/src/man/man1m/zpool.1m @@ -26,8 +26,9 @@ .\" Copyright (c) 2017 Datto Inc. .\" Copyright (c) 2017 George Melikov. All Rights Reserved. .\" Copyright 2019 Joyent, Inc. +.\" Copyright (c) 2012 Cyril Plisko. All Rights Reserved. .\" -.Dd May 15, 2019 +.Dd August 30, 2019 .Dt ZPOOL 1M .Os .Sh NAME @@ -39,10 +40,12 @@ .Nm .Cm add .Op Fl fgLnP +.Oo Fl o Ar property Ns = Ns Ar value Oc .Ar pool vdev Ns ... .Nm .Cm attach .Op Fl f +.Oo Fl o Ar property Ns = Ns Ar value Oc .Ar pool device new_device .Nm .Cm checkpoint @@ -668,6 +671,31 @@ changed with the .Nm zpool Cm set command: .Bl -tag -width Ds +.It Sy ashift Ns = Ns Sy ashift +Pool sector size exponent, to the power of +.Sy 2 +(internally referred to as +.Sy ashift +). Values from 9 to 16, inclusive, are valid; also, the +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. +For optimal performance, the pool sector size should be greater than or equal to +the sector size of the underlying disks. +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 +.Sy ashift=12 +(which is 1<<12 = 4096). When set, this property is +used as the default hint value in subsequent vdev operations (add, +attach and replace). +Changing this value will not modify any existing +vdev, not even on disk replacement; however it can be used, for +instance, to replace a dying 512B sectors disk with a newer 4KiB +sectors device: this will probably result in bad performance but at the +same time could prevent loss of data. .It Sy autoexpand Ns = Ns Sy on Ns | Ns Sy off Controls automatic pool expansion when the underlying LUN is grown. If set to @@ -838,6 +866,7 @@ Displays a help message. .Nm .Cm add .Op Fl fgLnP +.Oo Fl o Ar property Ns = Ns Ar value Oc .Ar pool vdev Ns ... .Xc Adds the specified virtual devices to the given pool. @@ -881,11 +910,19 @@ instead of only the last component of the path. This can be used in conjunction with the .Fl L flag. +.It Fl o Ar property Ns = Ns Ar value +Sets the given pool properties. +See the +.Sx Properties +section for a list of valid properties that can be set. +The only property supported at the moment is +.Sy ashift. .El .It Xo .Nm .Cm attach .Op Fl f +.Oo Fl o Ar property Ns = Ns Ar value Oc .Ar pool device new_device .Xc Attaches @@ -915,6 +952,13 @@ Forces use of .Ar new_device , even if its appears to be in use. Not all devices can be overridden in this manner. +.It Fl o Ar property Ns = Ns Ar value +Sets the given pool properties. +See the +.Sx Properties +section for a list of valid properties that can be set. +The only property supported at the moment is +.Sy ashift. .El .It Xo .Nm |