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from the someday-coming-to-a-phone-near-you? dept.
For those Linux folks out there, imagine merging LVM2, dm-raid, and your file system of choice into an all powerful, enterprise ready, check-summed, redundant, containerized, soft raid, disk pool, ram hungry, demi-god file system. The FreeBSD Handbook is a good start to grep the basic capabilities and function of ZFS[*].
The Ars reports:
A new long-term support (LTS) version of Ubuntu is coming out in April, and Canonical just announced a major addition that will please anyone interested in file storage. Ubuntu 16.04 will include the ZFS filesystem module by default, and the OpenZFS-based implementation will get official support from Canonical.
...
ZFS is used primarily in cases where data integrity is important—it's designed not just to store data but to continually check on that data to make sure it hasn't been corrupted. The oversimplified version is that the filesystem generates a checksum for each block of data. That checksum is then saved in the pointer for that block, and the pointer itself is also checksummed. This process continues all the way up the filesystem tree to the root node, and when any data on the disk is accessed, its checksum is calculated again and compared against the stored checksum to make sure that the data hasn't been corrupted or changed. If you have mirrored storage, the filesystem can seamlessly and invisibly overwrite the corrupted data with correct data.
ZFS was available as a technology preview in Ubuntu 15.10, but the install method was a bit more cumbersome than just apt-get install zfsutils-linux. I for one am excited to see ZFS coming to Linux as it is a phenomenal solution for building NAS devices and for making incremental backups of a file system. Now I just wish Ubuntu would do something about the systemD bug.
[*] According to Wikipedia:
ZFS is a combined file system and logical volume manager designed by Sun Microsystems. The features of ZFS include protection against data corruption, support for high storage capacities, efficient data compression, integration of the concepts of filesystem and volume management, snapshots and copy-on-write clones, continuous integrity checking and automatic repair, RAID-Z and native NFSv4 ACLs.
ZFS was originally implemented as open-source software, licensed under the Common Development and Distribution License (CDDL). The ZFS name is registered as a trademark of Oracle Corporation.
OpenZFS is an umbrella project aimed at bringing together individuals and companies that use the ZFS file system and work on its improvements.
(Score: 2, Interesting) by beardedchimp on Friday February 19 2016, @10:39AM
Could anyone give me use cases where I would be better off using ZFS instead of BTRFS?
(Score: 0) by Anonymous Coward on Friday February 19 2016, @11:40AM
When you're sending zfs snapshots to freebsd or solaris....
(Score: 2) by isostatic on Friday February 19 2016, @12:38PM
How stable is BTRFS?
ZFS went through teething problems many years ago -- http://www.uknof.org.uk/uknof13/Bird-Redux.pdf [uknof.org.uk]
First failure:
“Uberblock” and superblock got corrupted
Uberblock is for finding the superblock
Due to “copy on write”, previous copies of the
superblock are still on disk
Sun rolled it back to a previous copy, by
using `dd` to edit bytes on disk (!!)
Second failure:
This time they had better utilities
Fixed with less pain
Still not something the end user can do
However, Stuff was online again!
(Score: 2) by rleigh on Friday February 19 2016, @10:11PM
While the presentation may be missing some detail, it says that they ran ZFS on top of a hardware RAID array, which is not a recommended configuration. That might have been a contributing factor to the failure. It's recommended to run on plain discs so it can manage the RAID itself, e.g. for resilver. On the server I have, I reflashed the LSI HBA BIOS to put it in IT mode specifically so it was a dumb controller which would give ZFS direct access to all the storage. I could then add all the individual discs as components of each zvol, whereas for the hardware RAID case, you'll just see a single block device for each volume.
(Score: 2) by tangomargarine on Friday February 19 2016, @02:53PM
The few times I've tried BTRFS on my home desktop it took less than a month to crap its pants so I've been staying on ext4.
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
(Score: 0) by Anonymous Coward on Saturday February 20 2016, @11:15PM
Still on EXT3 here, as EXT4 has had some "oddities" recently.
(Score: 2) by rleigh on Friday February 19 2016, @07:45PM
When would you be better off using ZFS over Btrfs? I'll be quite blunt and say this: for every case.
ZFS is simply a much better filesystem. It's more robust, it's more featureful, and it's generally better performing. Btrfs still has major bugs and performance problems, and lacks a lot of the more advanced features of ZFS. I'd say use Btrfs if, and only if, you want to use one of the few features it has which ZFS does not (there are a couple of things, not that I've needed them myself).