Re: ZFS - quick start.

Pawel,

Quick question. Is it typical to ZFS to run over 100 kthreads? I see a 
lot of spa_*s in ps output.
Other bits are:
bland_at_nest:~$zpool list
NAME                    SIZE    USED   AVAIL    CAP  HEALTH     ALTROOT
tank                   4,19G    295M   3,90G     6%  ONLINE     -
bland_at_nest:~$zfs list
NAME         USED  AVAIL  REFER  MOUNTPOINT
tank         295M  3,83G    18K  /tank
tank/ports   294M  3,83G   294M  /usr/ports
tank/tmp     535K  3,83G   535K  /tmp

Thanks,
Alexander.

Pawel Jakub Dawidek wrote:
> Ok, ZFS is now in the tree, what's now? Below you'll find some
> instructions how to quickly make it up and running.
>
> First of all you need some disks. Let's assume you have three spare SCSI
> disks: da0, da1, da2.
>
> Add a line to your /etc/rc.conf to start ZFS automatically on boot:
>
> 	# echo 'zfs_enable="YES"' >> /etc/rc.conf
>
> Load ZFS kernel module, for the first time by hand:
>
> 	# kldload zfs.ko
>
> Now, setup one pool using RAIDZ:
>
> 	# zpool create tank raidz da0 da1 da2
>
> It should automatically mount /tank/ for you.
>
> Ok, now put /usr/ on ZFS and propose some file systems layout.  I know
> you probably have some files already, so we will work on /tank/usr
> directory and once we ready, we will just change the mountpoint to /usr.
>
> 	# zfs create tank/usr
>
> Create ports/ file system and enable gzip compression on it, because
> most likely we will have only text files there. On the other hand, we
> don't want to compress ports/distfiles/, because we keep compressed
> stuff already in-there:
>
> 	# zfs create tank/usr/ports
> 	# zfs set compression=gzip tank/usr/ports
> 	# zfs create tank/usr/ports/distfiles
> 	# zfs set compression=off tank/usr/ports/distfiles
>
> (You do see how your life is changing, don't you?:))
>
> Let's create home file system, my own home/pjd/ file system. I know we
> use RAIDZ, but I want to have directory where I put extremly important
> stuff, you I'll define that each block has to be stored in tree copies:
>
> 	# zfs create tank/usr/home
> 	# zfs create tank/usr/home/pjd
> 	# zfs create tank/usr/home/pjd/important
> 	# zfs set copies=3 tank/usr/home/pjd/important
>
> I'd like to have directory with music, etc. that I NFS share. I don't
> really care about this stuff and my computer is not very fast, so I'll
> just turn off checksumming (this is only for example purposes! please,
> benchmark before doing it, because it's most likely not worth it!):
>
> 	# zfs create tank/music
> 	# zfs set checksum=off tank/music
> 	# zfs set sharenfs=on tank/music
>
> Oh, I almost forget. Who cares about access time updates?
>
> 	# zfs set atime=off tank
>
> Yes, we set it only on tank and it will be automatically inherited by
> others.
>
> Will be also good to be informed if everything is fine with our pool:
>
> 	# echo 'daily_status_zfs_enable="YES"' >> /etc/periodic.conf
>
> For some reason you still need UFS file system, for example you use ACLs
> or extended attributes which are not yet supported by our ZFS. If so,
> why not just use ZFS to provide storage? This way we gain cheap UFS
> snapshots, UFS clones, etc. by simply using ZVOLs.
>
> 	# zfs create -V 10g tank/ufs
> 	# newfs /dev/zvol/tank/ufs
> 	# mount /dev/zvol/tank/ufs /ufs
>
> 	# zfs snapshot tank/ufs_at_20070406
> 	# mount -r /dev/zvol/tank/ufs_at_20070406 /ufs20070406
>
> 	# zfs clone tank/ufs_at_20070406 tank/ufsok
> 	# fsck_ffs -p /dev/zvol/tank/ufsok
> 	# mount /dev/zvol/tank/ufsok /ufsok
>
> Want to encrypt your swap and still use ZFS? Nothing more trivial:
>
> 	# zfs create -V 4g tank/swap
> 	# geli onetime -s 4096 /dev/zvol/tank/swap
> 	# swapon /dev/zvol/tank/swap.eli
>
> Trying to do something risky with your home? Snapshot it first!
>
> 	# zfs snapshot tank/home/pjd_at_justincase
>
> Turns out it was more stupid than risky? Rollback your snapshot!
>
> 	# zfs rollback tank/home/pjd_at_justincase
> 	# zfs destroy tank/home/pjd_at_justincase
>
> Ok, everything works, we may set tank/usr as our real /usr:
>
> 	# zfs set mountpoint=/usr tank/usr
>
> Don't forget to read zfs(8) and zpool(8) manual pages and SUN's ZFS
> administration guide:
>
> 	http://www.opensolaris.org/os/community/zfs/docs/zfsadmin.pdf
>
>