RAID expansion comes to OpenZFS at last
- Reference: 1644588733
- News link: https://www.theregister.co.uk/2022/02/11/raid_expansion_openzfs/
- Source link:
Filesystems are one of the core differentiators between enterprise Linux distributions (and other Unix and Unix-like OSes). That means, like anything in the Unix world, there's "advocacy" – in other words, bitter squabbling about which is best or worst.
ZFS was originally [2]developed by Sun for Solaris . At one point, Apple [3]was going to adopt it , but [4]changed its mind . Now, of course, [5]Oracle owns it – but [6]there is OpenZFS , and a very small chance that [7]the situation might change .
[8]
You can use OpenZFS on Linux; the problem is building it into the kernel because Sun's Common Development and Distribution Licence is [9]incompatible with Linux's GPL2 . Despite this, Ubuntu [10]added ZFS support in 2016 and [11]enabled ZFS on root in 2019.
[12]KDE Community releases Plasma 5.24: It's eccentric, just like many old-timers
[13]They see us Cinnamon Rolling, they're rating: GeckoLinux incorporates kernel 5.16 with familiar installation experience
[14]OpenZFS v2.0.0 targets Linux and FreeBSD – shame about the Oracle licensing worries
[15]Do not try this at home: Man spends $5,000 on a 48TB Raspberry Pi storage server
Btrfs is not so encumbered. Also, it's quite straightforward to add new [16]devices to a Btrfs filesystem, or [17]resize one. This has led several commentators to [18]praise Btrfs's [19]flexibility . Naturally, others have long claimed the [20]reverse .
There are still significant [21]caveats with the new online expansion functionality, but even so, this new ability is useful and counters one criticism of OpenZFS. ®
Get our [22]Tech Resources
[1] https://freebsdfoundation.org/blog/raid-z-expansion-feature-for-zfs-goes-live/
[2] https://www.theregister.com/2005/11/02/sun_zfs_coming/
[3] https://www.theregister.com/2007/06/07/apple_using_zfs_in_leopard/
[4] https://www.theregister.com/2009/06/10/snow_leopard_no_zfs/
[5] https://www.theregister.com/2009/04/20/oracle_buys_sun/
[6] https://www.theregister.com/2020/12/01/zfs_on_linux_now_openzfs/
[7] https://www.theregister.com/2017/10/26/oracle_considers_letting_zfs_into_linux/
[8] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/storage&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2YgaWNwQUiZqvM5FJyg@@xwAAAIQ&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[9] https://www.theregister.com/2020/01/13/zfs_linux/
[10] https://www.theregister.com/2016/04/21/ubuntu_16_04_lts_launched/
[11] https://www.theregister.com/2019/08/12/canonical_zfs_ubuntu/
[12] https://www.theregister.com/2022/02/09/plasma_524/
[13] https://www.theregister.com/2022/01/24/geckolinux/
[14] https://www.theregister.com/2020/12/01/zfs_on_linux_now_openzfs/
[15] https://www.theregister.com/2021/11/18/48tb_rapsberry_pi_nas/
[16] https://btrfs.wiki.kernel.org/index.php/Using_Btrfs_with_Multiple_Devices#Adding_new_devices
[17] https://linuxhint.com/resize_a_btrfs_filesystem/
[18] https://markmcb.com/2020/01/07/five-years-of-btrfs/
[19] https://mutschler.eu/linux/btrfs/
[20] https://rudd-o.com/linux-and-free-software/ways-in-which-zfs-is-better-than-btrfs
[21] https://louwrentius.com/zfs-raidz-expansion-is-awesome-but-has-a-small-caveat.html
[22] https://whitepapers.theregister.com/
Someone who has contributed code to the Linux kernel could sue for breach of their copyright.
I believe Oracle has contributed code to the Linux kernel.
That one gave me a good chuckle, it's so far-fetched, and yet asserted with such a straight face.
Using their copyright over some bits of their code in Linux, they would sue Canonical for, let me see, breaching the license of Linux by using code that contains huge bits under Oracle copyright, and for which they themselves (as buyers of the previous owner) picked the license that they'd be asserting is in violation of the GPL.
One may dislike Oracle without believing them to be utterly stupid :)
I don't know what they have contributed to Linux, but lets suppose it is stuff related to VirtualBox.
Canonical is of course free to distribute that. What they might not be free to do is combine it with zfs-related stuff and distribute the resulting product.
Yes yes yes!
Thank you - was checking the status of this just a couple of weeks ago, as I had to do a migration while missing a physical disk.
Getting it to boot on Linux is still more of chore than it should be, but once you're up and running OpenZFS is just great. I still remember the dance of ext-on-lvm-on-devices and what a surprise it was when I first hit zfs. CLI tools that were coherent, easy to understand and complete. Most unexpected.
BTRFS on the other hand... I didn't go back after I hit a disk full situation that couldn't be recovered by deleting files. I don't want a hobby project running my disks.
Re: Yes yes yes!
Thanks for the heads up on Btrfs, I'm looking at a Raid 5 device that is near its limit right now, though 10% not 3%.
Guessing from what you said, the array crashed went into read only mode. Before choosing Btrfs, we had a test server set up using small 5 x 250GB drives, and pulled drives, to simulate failed disks, implementing a rebuild to get a good understanding of issues and time to rebuild etc.
Even though we did test a raid array to near capacity, the main thing I remember is the transfers stopping before the limit was reached, and you'd lose access to the server over the network, based on notifications that 3% storage remained, then it would come back. But the raid remained healthy, on checking it.
Might check this again with the test server, time constraints, mean you never get to fully test stuff.
In fairness though, with spare capacity, not reaching it's capacity, Btrfs has been rock solid for several years now. It's a server that regularly powers down, and starts up again with WOL (wake on lan).
Re: Yes yes yes!
Original AC here - to be fair this was at least a decade ago, things move on. And for full disclosure I recently hit issues with ZFS going beserk (ZFS and Java both optimistically reserve memory, so you need to enforce some limits on ZFS to stop Java hitting the stops. But set those limits wrong and the cache flush process goes bananas - first time I've seen a three figure load average).
Otherwise, highly recommended. My recent migration involved raidz from 5 x 1TB to raidz on 4 x 2TB, which I had to connect over USB as I didn't have enough bays. Snapshot, zfs send pipe to zfs receive, done. Follow with the usual collection of grub2 incantations and burnt offerings to the bootloader gods, and after about 300 attempts it came up first time...
Re: Yes yes yes!
Indeed, as someone who has used FreeBSD + zfs as a daily driver since v8 came out about 12 years ago, any time I use something different, I very quickly get frustrated with how pants their filesystem is in comparison.
monsters...
Take md RAID (which you can reshape any way you like) and put a filesystem of your choice on top. And avoid these unholy raid+fs hybrids like plague.
Re: monsters...
Your username hints at some bias on this topic!
"(It is worth pointing out that according to the legal principle of laches, it's now too late for Big Red to sue, but that still puts off most Linux vendors.)"
To sue? To sue who, about what? Oracle doesn't own the Linux kernel, whose license would allegedly be breached by using OpenZFS as a separate module. They own Solaris, which includes its own, now proprietary licensed ZFS.
Nobody ever claimed that OpenZFS was in breach of the license of the formerly Sun, now Oracle code it's based on, which was published under the CDDL.