Zettabyte File System

== Summary ==

Within ZFS, file system creation and manipulation within zpool storage is closer to that of making a new directory than it is to volume manipulation in a traditional file system sense.  This wiki article will attempt to cover some of the finer points of creating, manipulating, and managing zfs virtual file systems within a zpool.

''If you haven't already done so please read the wiki section on creating [[https://wiki.ubuntu.com/ZFS/ZPool | ZFS ZPools]] before continuing.  The rest of the wiki article will assume that you have ZFS, via Fuse, installed and one or more ZPools created.''

== Creating File Systems Within a ZPool ==

=== Why create a virtual file system within a ZFS ZPool? ===

The purpose of creating virtual file systems on a zpool is to segment data or create administrative control points.  Say you've created a ZPool but you want to encrypt part of the file system structure but not the rest of the ZPool. You want to put home directories in a ZPool but you want to have the ability to create individual block level snapshots of the users home directory or set quota's.   Compress a section of a ZPool but not the rest. These are only a few reasons to create virtual file systems on a ZPool. Listed below are some of the options available to zfs file systems. 

'''From the zfs man page'''  

{{{
zfs create filesystem
zfs create [-s] [-b blocksize] -V size volume
zfs destroy [-rRf] filesystem|volume|snapshot
zfs clone snapshot filesystem|volume
zfs rename  filesystem|volume|snapshot filesystem|volume|snapshot
zfs snapshot  filesystem@name|volume@name
zfs rollback [-rRf] snapshot
zfs list [-rH] [-o property[,property]...] [ -t type[,type]...] 
	[filesystem|volume|snapshot] ...
zfs set property=value filesystem|volume...
zfs get [-rHp] [-o field[,field]...] [-s source[,source]...] all | 
	property[,property]... filesystem|volume|snapshot...
zfs inherit [-r] property filesystem|volume...
zfs mount
zfs mount [-o options] [-O] -a
zfs mount [-o options] [-O] filesystem
zfs unmount [-f] -a
zfs unmount [-f] [filesystem|mountpoint]
zfs share -a
zfs share filesystem
zfs unshare [-f] -a
zfs unshare [-f] [filesystem|mountpoint]
zfs backup [-i snapshot] snapshot
zfs restore [-vn ] filesystem|volume|snapshot
zfs restore [-vn ] -d filesystem

}}}


=== Creating ZFS file systems ===

'''So let setup a couple zfs file systems but lets first look at our ZPool(s).'''

{{{
zpool status
}}}

''For this example the zpool will be called vol0 and look like:''

{{{
root@ubuntu:~# zpool status
  pool: vol0
 state: ONLINE
 scrub: none requested
config:

	NAME        STATE     READ WRITE CKSUM
	vol0        ONLINE       0     0     0
	  raidz1    ONLINE       0     0     0
	    sdb     ONLINE       0     0     0
	    sdc     ONLINE       0     0     0
	    sdd     ONLINE       0     0     0
	    sde     ONLINE       0     0     0
	spares
	  sdf       AVAIL   
	  sdg       AVAIL   

errors: No known data errors
}}}

''And the base file system layout looks like:''

{{{
root@ubuntu:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             7.5G  1.3G  5.9G  18% /
tmpfs                 125M     0  125M   0% /lib/init/rw
varrun                125M   56K  125M   1% /var/run
varlock               125M     0  125M   0% /var/lock
udev                  125M  2.7M  122M   3% /dev
tmpfs                 125M     0  125M   0% /dev/shm
vol0                   30G   27K   30G   1% /vol0
}}}



== ZFS Best Practices ==