if using BTRFileSystem

[ralul]

This is not a general Debian issue as Wheezy is stuck with Linux-3.2. But with siduction use of btrfs might become problematic!
I just saw this news while upgrading my Gentoo installation:

btrfs-progs-0.19-r3::gentoo
# Joe Peterson <lavajoe@gentoo.org> (02 Jul 2012)
# This old version has become out of sync with kernel btrfs, so is dangerous
# (except for those who have an older kernel and know what they are doing).
# Use of the live build (btrfs-progs-9999) is recommended, since no upstream
# versioning is available, and the live build keeps pace with new kernels.
# See bug #420477

Gentoo "live build" is a notion for compiling directly from upstream git source ...

[dibl]

Which kernel version appears with this warning?

Thank ralul.

[DeepDayze]

For Debian, could there be a script thrown together for building this package?

[ralul]

The bug link https://bugs.gentoo.org/show_bug.cgi?id=420477
tells something about using Linux-3.4
This is why reading it, I thought about you guys!

But myself beware of such an unstable filesystem yet ...

[dibl]

I have been running a btrfs filesystem since December, 2010. This is installed on a pair of WD1002FAEX "SATA III" drives, connected to the Marvell 9128 6Gb/s controller on my Asus P6X58D-E system board.

Code Select Expand

root@imerabox:/# blkid -c /dev/null -o list                                                            
device               fs_type   label      mount point              UUID                                
-------------------------------------------------------------------------------------------------------
/dev/sda1            ext4                 /                        bea3a748-3411-4024-acd0-39f3882ddaf9
/dev/sda2            ext4      SDA2       /mnt/SDA2                8cfe2acc-7572-4b45-b25f-ed021bb1d78b
/dev/sdb1            ext4      revodata   /mnt/REVODATA            ec21f5b3-7fd4-4f4b-af8d-cf787b147ae8
/dev/sdc1            ext2                 /boot                    ac7da829-aebb-46f0-806c-04a4d81a945a
/dev/sdc2            swap                 <swap>                   0d939b7d-48f1-47dd-aebe-77e7bd8c3503
/dev/sdd             btrfs                (in use)                 c112ed57-0e33-4d4b-82c9-5c55932c529d
/dev/sde             btrfs                (in use)                 c112ed57-0e33-4d4b-82c9-5c55932c529d

Today I checked it:

Code Select Expand

root@imerabox:/# btrfs filesystem show
failed to read /dev/sr0
Label: none  uuid: c112ed57-0e33-4d4b-82c9-5c55932c529d
       Total devices 2 FS bytes used 771.37GB
       devid    2 size 931.51GB used 519.63GB path /dev/sde
       devid    1 size 931.51GB used 519.65GB path /dev/sdd                                            
                                                                                                       
Btrfs Btrfs v0.19                                                                                      
root@imerabox:/# btrfs filesystem df /mnt/DATA                                                        
Data, RAID0: total=964.00GB, used=769.82GB                                                              
Data: total=8.00MB, used=0.00                                                                          
System, RAID1: total=8.00MB, used=84.00KB                                                              
System: total=4.00MB, used=0.00                                                                        
Metadata, RAID1: total=37.62GB, used=1.56GB                                                            
Metadata: total=8.00MB, used=0.00

I ran

Code Select Expand

root@imerabox:/# btrfs scrub start /mnt/DATA
scrub started on /mnt/DATA, fsid c112ed57-0e33-4d4b-82c9-5c55932c529d (pid=4572)

(couple of hours later after it finished):

Code Select Expand

root@imerabox:/# btrfs scrub status /mnt/DATA
scrub status for c112ed57-0e33-4d4b-82c9-5c55932c529d                                                  
       scrub started at Wed Jul  4 13:47:02 2012 and finished after 3577 seconds                      
       total bytes scrubbed: 772.93GB with 0 errors

So, it seems OK at this point.  Probably a good time to back up ....

[DeepDayze]

How does btrfs stack up against the existing filesystems as well as ZFS?

[dibl]

BTRFS is clearly designed for one target application -- massive, flexible storage.  Think of server farms and cluster computing.  I don't think it offers any advantage for running an OS -- it is not faster than ext4.  It offers multi-device performance very similar to RAID, with no special controllers or drivers, so that makes life simpler.  For my 2-drive BTRFS filesystem, I used the default options, which sets metadata to be mirrored (similar to RAID 1) and data to be striped (similar to RAID 0).  I have not done any benchmark testing -- you can read in Phoronix and elsewhere how the performance compares to ext4.  I have about 750GB of music, videos, images, and docs in my /mnt/DATA filesystem, and it has shown no problems in 18 months.  When I first installed it, there was no defrag and no fsck available.  The first time I ran scrub (the btrfs version of fsck), it found correctible errors on 13 inodes, and fixed them, and there were zero non-correctible errors.  It has never found any more errors, as you see above.  I worked through a full defrag one time, which is a 2-step process, and that went fine.  But I kinda think it was not necessary, similar to ext4.

I have never tried ZFS -- I can't comment on that one.

[ralul]

all what dibl said
plus snapshot feature - this would be interesting for use with Debian sid: All of the troubles gone ...

[DeepDayze]

Btrfs does sound promising, and looking forward to trying this on my home NAS once it is rock solid.

Filesystems are quite complex underneath the hood so it must take a lot of time to debug and tune

all what dibl said
plus snapshot feature - this would be interesting for use with Debian sid: All of the troubles gone ...

Would be cool to easily roll back should you mess up a DU or a major bug creeps in.

Testing software would also be a breeze so should something break or that you don't want the app, just roll back!

[dibl]

plus snapshot feature - this would be interesting for use with Debian sid: All of the troubles gone ...

Huh -- I had not thought of that, but that is one good reason to run this OS on btrfs.

Hmmm, I think maybe Windows could use btrfs!   :twisted:

[agaida]

dibl,
Windows dont need this feature, since they have a similar thing in windows 8. And for the records: they have partial backups of systemsettings before updates ages ago.

EDIT: I don't think the so called "Wiederherstellungspunkte" are usable - but i think at the same development level like btrfs. They simply dont work in 8/10 Times.

[ralul]

That Ms "Wiederherstellungspunkt" (nobody knows the english word) is something artificial on higher OS level. A Btrfs-snapshot is the original filesystem before the snapshot without any copying - very low level.

[dibl]

That Ms "Wiederherstellungspunkt" (nobody knows the english word)

Is that what MS called "System Restore" on Win XP, under the System Tools?

I never knew anyone who saved their Windows system with that junk -- I don't think the viruses respected it.    :lol:

[vilde]

Wiederherstellungspunkt = Återställningspunkt in Swedish, I don't either know the English word and it never worked for me either

[DeepDayze]

plus snapshot feature - this would be interesting for use with Debian sid: All of the troubles gone ...

Huh -- I had not thought of that, but that is one good reason to run this OS on btrfs.

Hmmm, I think maybe Windows could use btrfs!   :twisted:

Just what we need..a "system restore" for Linux :lol: