Linked by Thom Holwerda on Mon 7th Jun 2010 10:15 UTC, submitted by kragil
Linux Employees of Lawrence Livermore National Laboratory have ported Sun's/Oracle's ZFS natively to Linux. Linux already had a ZFS port in userspace via FUSE, since license incompatibilities between the CDDL and GPL prevent ZFS from becoming part of the Linux kernel. This project solves the licensing issue by distributing ZFS as a separate kernel module users will have to download and build for themselves.
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RE: brtfs
by phoenix on Mon 7th Jun 2010 19:29 UTC in reply to "brtfs"
phoenix
Member since:
2005-07-11

btrfs doesn't support pooled storage.
btrfs doesn't support RAID levels above 1 (RAID10 is not higher than 1).
btrfs doesn't do end-to-end checksumming and self-healing.
btrfs doesn't do encryption (still an experimental feature in ZFS, but it's being worked on).
btrfs doesn't do deduplication.

Those are just some things I can think of off the top of my head. There's bound to be a lot more, considering the relative immaturity of the btrfs codebase compared to the ZFS codebase.

IOW, btrfs is where ZFS was 10 years ago. Explain to me again how btrfs is so much better, and will rule the storage world? ;)

Reply Parent Score: 5

RE[2]: brtfs
by Tuxie on Mon 7th Jun 2010 23:08 in reply to "RE: brtfs"
Tuxie Member since:
2009-04-22

One of the ZFS features I think is coolest is L2ARC which let you put a fast SSD as a read/write-cache in front of a pool of slower mechanical disks. The blocks you use most frequently will have a copy on the SSD for quick access. IIRC the cache currently doesn't survive a reboot though (it will start caching from scratch again), but they are working on fixing that.

Reply Parent Score: 1

RE[3]: brtfs
by phoenix on Mon 7th Jun 2010 23:24 in reply to "RE[2]: brtfs"
phoenix Member since:
2005-07-11

Yes, cache vdevs are very handy. And they are absolutely essential for dedupe to work correctly/quickly.

Even a lowly USB flash stick can be used as a cache vdev ... so long as the read speed of the USB stack/driver/port/disk is faster than the read speed of the harddrive.

I use 4 GB USB sticks at home to speed up my pokey 120 GB SATA (non-NCQ, 1.5 GB/s) drives.

There's even support for using SSDs for write caching (log vdevs), although it's a lot harder to find SSDs that are optimised for writes (SLC-based) that include onboard power (supercap, for example) and that honour cache flush/sync requests.

Reply Parent Score: 2

RE[2]: brtfs
by diegocg on Wed 9th Jun 2010 13:25 in reply to "RE: brtfs"
diegocg Member since:
2005-07-08

Duh, btrfs has pool storage, patches to support other raid levels and end-to-end checksumming. Self-healing, deduplication and encryption will be added later once other basic features (shich as direct-IO) are added and stabilized.

Reply Parent Score: 2

RE[3]: brtfs
by phoenix on Wed 9th Jun 2010 14:46 in reply to "RE[2]: brtfs"
phoenix Member since:
2005-07-11

RAID 5/6 support has not been checked in yet, nor has it really been made available for testing beyond the two devs working on it. Thus, it doesn't support RAID levels above 1 yet.

Nor does it really support pooled storage, as you still have to specify the harddrives that will be used for each filesystem when you create the filesystem. There's no pool management yet, just filesystem management.

So, like I said, btrfs is where zfs was 10 years ago. It's not a replacement for zfs in any way at this time.

Maybe in 5 years, it'll be where zfs is now. But it's not there yet.

Reply Parent Score: 2

RE[3]: brtfs
by Kebabbert on Wed 9th Jun 2010 19:16 in reply to "RE[2]: brtfs"
Kebabbert Member since:
2007-07-27

BTRFS has end-to-end checksumming? I doubt it is well designed unless I see proof. BTRFS developers only recently understood that data integrity is important and decided to add that as an afterthought. What a fail. You need to design the whole file system from the ground up. For instance, reiserfs, JFS, XFS, etc nor raid-5 nor raid-6 does not give a good protection.

As I said, you need lots of experience from Enterprise storage to know how to tackle problems that arise from large scale storage.

Linux does not suffice for large scale storage. It sucks badly on Enterprise storage according to an storage expert:
http://www.enterprisestorageforum.com/sans/features/article.php/374...

http://www.enterprisestorageforum.com/sans/features/article.php/374...



BTW, ZFS was announced 2004. But it was prototyped and worked on, several years earlier. It is highly possible ZFS has existed 10 years today.

Reply Parent Score: 2