On 22/07/2010, at 12:35, Dan Langille wrote: > Why use glabel? > > * So ZFS can find and use the correct HDD should the HDD device ever > get renumbered for whatever reason. e.g. /dev/da0 becomes /dev/da6 > when you move it to another controller. > > Why use partitions? > > * Primarily: two HDD of a given size, say 2TB, do not always provide > the same amount of available space. If you use a slightly smaller > partition instead of the entire physical HDD, you're much more > likely to have a happier experience when it comes time to replace an > HDD. > > * There seems to be a consensus amongst some that leaving the start and > and of your HDD empty. Give the rest to ZFS.
I would combine both! GPT generates a UUID for each partition and glabel presents this so ZFS can use it, eg I have.. [cain 19:45] ~ >sudo zpool status pool: tank state: ONLINE scrub: none requested config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 raidz2 ONLINE 0 0 0 gptid/d7467802-418f-11df-bcfc-001517e077fb ONLINE 0 0 0 gptid/d7eeeced-418f-11df-bcfc-001517e077fb ONLINE 0 0 0 gptid/d8761aa0-418f-11df-bcfc-001517e077fb ONLINE 0 0 0 gptid/d9083d18-418f-11df-bcfc-001517e077fb ONLINE 0 0 0 gptid/d97203ec-418f-11df-bcfc-001517e077fb ONLINE 0 0 0 and on each disk.. [cain 19:46] ~ >gpart list ada0 Geom name: ada0 fwheads: 16 fwsectors: 63 last: 1953525134 first: 34 entries: 128 scheme: GPT Providers: 1. Name: ada0p1 Mediasize: 8589934592 (8.0G) Sectorsize: 512 Mode: r0w0e0 rawtype: 516e7cb5-6ecf-11d6-8ff8-00022d09712b label: (null) length: 8589934592 offset: 17408 type: freebsd-swap index: 1 end: 16777249 start: 34 2. Name: ada0p2 Mediasize: 991614917120 (924G) Sectorsize: 512 Mode: r1w1e2 rawtype: 516e7cba-6ecf-11d6-8ff8-00022d09712b label: (null) length: 991614917120 offset: 8589952000 type: freebsd-zfs index: 2 end: 1953525134 start: 16777250 Consumers: 1. Name: ada0 Mediasize: 1000204886016 (932G) Sectorsize: 512 Mode: r1w1e3 The only tedious part is working out which drive has what UUIDs on it because gpart doesn't list them. The advantage of using the UUIDs is that if you setup another machine the same way you don't have to worry about things when you plug in the disks from it to recover something. Or perhaps you are upgrading at the same time as replacing hardware so you have all the disks in at once. > Create a new partition within that scheme: > > gpart add -b 34 -s SOMEVALUE -t freebsd-zfs ad0 > > Why '-b 34'? Randi pointed me to > http://en.wikipedia.org/wiki/GUID_Partition_Table where it explains what the > first 33 LBA are used for. It's not for us to use here. If you don't specify -b it will DTRT - that's how I did it. You can also specify the size (and start) in human units (Gb etc). -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"