Wael Nasreddine (a.k.a eMxyzptlk)
2009-Nov-08 15:09 UTC
[zfs-discuss] What can I get with 2x250Gb ?
Hello, I''m sure this question has been asked many times already, but I couldn''t find the answer myself. Anyway I have a laptop with 2 identical hard disks 250Gb each, I''m currently using Linux on RAID0 which gave me ~500Gb.. I''m planning to switch to FreeBSD but I want to know before I do, what can I get with these hard disks? do I get ~500Gb or less? can ZFS be setup to use RAIDz with only 2 hard disks ? Thank you -- Wael Nasreddine Weem Chief-Development Officer - http://www.weem.com Blog : http://wael.nasreddine.com E-mail : wael.nasreddine at weem.com gTalk : wael.nasreddine at gmail.com Tel : +33.6.32.94.70.13 Skype : eMxyzptlk Twitter : @eMxyzptlk PGP: 1024D/C8DD18A2 06F6 1622 4BC8 4CEB D724 DE12 5565 3945 C8DD 18A2 .: An infinite number of monkeys typing into GNU emacs, would never make a good program. (L. Torvalds 1995) :. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.opensolaris.org/pipermail/zfs-discuss/attachments/20091108/6df2ba04/attachment.html>
If you want any kind of data guarantee, you need to go for a mirrored pool. If you don''t want a data guarantee, you can create a single pool (non-mirrored) of the two devs which will give you 500Gb. The key is in the ''zpool create'' command zpool create twofifty mirror disk1 disk2 zpool create fivehundred disk1 disk2 Alex On Nov 8, 2009, at 15:09, Wael Nasreddine (a.k.a eMxyzptlk) wrote:> Hello, > > I''m sure this question has been asked many times already, but I > couldn''t find the answer myself. Anyway I have a laptop with 2 > identical hard disks 250Gb each, I''m currently using Linux on RAID0 > which gave me ~500Gb.. > > I''m planning to switch to FreeBSD but I want to know before I do, > what can I get with these hard disks? do I get ~500Gb or less? can > ZFS be setup to use RAIDz with only 2 hard disks ? > > Thank you > > -- > Wael Nasreddine > > Weem Chief-Development Officer - http://www.weem.com > > Blog : http://wael.nasreddine.com > E-mail : wael.nasreddine at weem.com > gTalk : wael.nasreddine at gmail.com > Tel : +33.6.32.94.70.13 > Skype : eMxyzptlk > Twitter : @eMxyzptlk > > PGP: 1024D/C8DD18A2 06F6 1622 4BC8 4CEB D724 DE12 5565 3945 C8DD 18A2 > > .: An infinite number of monkeys typing into GNU emacs, > would never make a good program. (L. Torvalds 1995) :. > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.opensolaris.org/pipermail/zfs-discuss/attachments/20091108/e7941c78/attachment.html>
Wael Nasreddine (a.k.a eMxyzptlk)
2009-Nov-08 15:22 UTC
[zfs-discuss] What can I get with 2x250Gb ?
Since all my data are on this PC and I have many externals HDDs (around 3Tb) I think I''m gonna go with Mirrored setup, protect my data.. but out of curiosity, if someday I decide I want 500Gb, can mirrored setup be switched to single devs on the fly or a complete array rebuild is necessary? On Sun, Nov 8, 2009 at 16:13, Alex Blewitt <alex.blewitt at gmail.com> wrote:> If you want any kind of data guarantee, you need to go for a mirrored pool. > If you don''t want a data guarantee, you can create a single pool > (non-mirrored) of the two devs which will give you 500Gb. The key is in the > ''zpool create'' command > > zpool create twofifty mirror disk1 disk2 > zpool create fivehundred disk1 disk2 > > Alex > > On Nov 8, 2009, at 15:09, Wael Nasreddine (a.k.a eMxyzptlk) wrote: > > Hello, > > I''m sure this question has been asked many times already, but I couldn''t > find the answer myself. Anyway I have a laptop with 2 identical hard disks > 250Gb each, I''m currently using Linux on RAID0 which gave me ~500Gb.. > > I''m planning to switch to FreeBSD but I want to know before I do, what can > I get with these hard disks? do I get ~500Gb or less? can ZFS be setup to > use RAIDz with only 2 hard disks ? > > Thank you > > -- > Wael Nasreddine > > Weem Chief-Development Officer - http://www.weem.com > > Blog : http://wael.nasreddine.com > E-mail : wael.nasreddine at weem.com > gTalk : wael.nasreddine at gmail.com > Tel : +33.6.32.94.70.13 > Skype : eMxyzptlk > Twitter : @eMxyzptlk > > PGP: 1024D/C8DD18A2 06F6 1622 4BC8 4CEB D724 DE12 5565 3945 C8DD 18A2 > > .: An infinite number of monkeys typing into GNU emacs, > would never make a good program. (L. Torvalds 1995) :. > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > > >-- Wael Nasreddine Weem Chief-Development Officer - http://www.weem.com Blog : http://wael.nasreddine.com E-mail : wael.nasreddine at weem.com gTalk : wael.nasreddine at gmail.com Tel : +33.6.32.94.70.13 Skype : eMxyzptlk Twitter : @eMxyzptlk PGP: 1024D/C8DD18A2 06F6 1622 4BC8 4CEB D724 DE12 5565 3945 C8DD 18A2 .: An infinite number of monkeys typing into GNU emacs, would never make a good program. (L. Torvalds 1995) :. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.opensolaris.org/pipermail/zfs-discuss/attachments/20091108/74d980f5/attachment.html>
A zpool consists of vdevs (a group of discs). You can create a mirror of your 250GB. And later you can add another group of discs to your zpool, on the fly. Each group of discs should have redundancy, for instance, mirror, raidz1 or raidz2. So you can add vdev to a zpool on the fly, but you can not remove a vdev from a zpool. You can not change a vdev to another configuration. You can swap each drive in a vdev to a larger. -- This message posted from opensolaris.org
Wael Nasreddine (a.k.a eMxyzptlk)
2009-Nov-08 15:59 UTC
[zfs-discuss] What can I get with 2x250Gb ?
Gotcha. Thank you. On Sun, Nov 8, 2009 at 16:42, Orvar Korvar <knatte_fnatte_tjatte at yahoo.com>wrote:> A zpool consists of vdevs (a group of discs). You can create a mirror of > your 250GB. And later you can add another group of discs to your zpool, on > the fly. Each group of discs should have redundancy, for instance, mirror, > raidz1 or raidz2. So you can add vdev to a zpool on the fly, but you can not > remove a vdev from a zpool. You can not change a vdev to another > configuration. You can swap each drive in a vdev to a larger. > -- > This message posted from opensolaris.org > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >-- Wael Nasreddine Weem Chief-Development Officer - http://www.weem.com Blog : http://wael.nasreddine.com E-mail : wael.nasreddine at weem.com gTalk : wael.nasreddine at gmail.com Tel : +33.6.32.94.70.13 Skype : eMxyzptlk Twitter : @eMxyzptlk PGP: 1024D/C8DD18A2 06F6 1622 4BC8 4CEB D724 DE12 5565 3945 C8DD 18A2 .: An infinite number of monkeys typing into GNU emacs, would never make a good program. (L. Torvalds 1995) :. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.opensolaris.org/pipermail/zfs-discuss/attachments/20091108/36370863/attachment.html>
On Sun, 8 Nov 2009, Wael Nasreddine (a.k.a eMxyzptlk) wrote:> > I''m sure this question has been asked many times already, but I couldn''t find the answer > myself. Anyway I have a laptop with 2 identical hard disks 250Gb each, I''m currently using > Linux on RAID0 which gave me ~500Gb.. > > I''m planning to switch to FreeBSD but I want to know before I do, what can I get with these > hard disks? do I get ~500Gb or less? can ZFS be setup to use RAIDz with only 2 hard disks ?Since FreeBSD was mentioned, if FreeBSD supports zfs boot, then you can use mirrors and get 250GB. Otherwise (if no other boot device is available) you will need to use disk partitioning and boot from a UFS (FFS) filesystem. In this case you can still use a zfs mirror, but only across partitions. Your boot would not be protected but if you partition the disks identically, perhaps you can duplicate your boot/root environment, or perhaps FreeBSD offers a different mechanism to mirror the root partition which is also bootable. If maximizing disk space is important to you, you don''t have to use zfs mirroring, but most people here would recommend it. Bob -- Bob Friesenhahn bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/