Displaying 20 results from an estimated 20000 matches similar to: "Various Questions"
2010 Dec 06
9
"Appending" data to the middle of a file using btrfs-specific features
Hello,
I''d like to know if there has been any discussion about adding a new
feature to write (add) data at an offset, but without overwriting
existing data, or re-writing the existing data. Essentially, in-place
addition/removal of data to a file at a place other than the end of
the file.
Some possible use-cases of such a feature would be:
(a) Databases (currently hack around this by
2011 Jul 09
10
Kernel Modules
Just compiled a custom kernel, but unable to mount a btrfs partition. It essentially says ''unrecognized filesystem''. What could be missing?
# File systems
#
CONFIG_EXT2_FS=y
CONFIG_EXT2_FS_XATTR=y
CONFIG_EXT2_FS_POSIX_ACL=y
CONFIG_EXT2_FS_SECURITY=y
# CONFIG_EXT2_FS_XIP is not set
CONFIG_EXT3_FS=y
CONFIG_EXT3_DEFAULTS_TO_ORDERED=y
CONFIG_EXT3_FS_XATTR=y
2012 Apr 01
19
cross-subvolume cp --reflink
Glück Auf!
I know its been discussed more then ones, but as a user I really would like to see the patch for allowing this in the kernel.
Some users tested this patch successfully for weeks or months in 2 or 3 kernel versions since then, true?
I''d say by creating a snapshot, it''s nothing else in the end. More then one file or tree sharing the same data on disc, or am I wrong?
2011 Oct 23
2
Subvolume level allocation policy
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Is it ( yet? ) possible to manipulate the allocation policy on a
subvolume level instead of the fs level? For example, to make / use
raid1, and /home use raid0? Or to have / allocated from an ssd and
/home allocated from the giant 2tb hd.
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2012 Oct 25
46
[RFC] New attempt to a better "btrfs fi df"
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Hi all,
this is a new attempt to improve the output of the command "btrfs fi df".
The previous attempt received a good reception. However there was no a
general consensus about the wording.
Moreover I still didn''t understand how btrfs was using the disks.
A my first attempt was to develop a new command which shows how the
disks
2013 Apr 03
2
[bug] btrfs fi df doesn't show raid type after balance
Did something break.. ? we are not reporting raid type after balance.
-----------
# btrfs fi df /btrfs
Data, RAID0: total=2.00GB, used=2.03MB
Data: total=8.00MB, used=0.00
System, RAID0: total=16.00MB, used=4.00KB
System: total=4.00MB, used=0.00
Metadata, RAID0: total=2.00GB, used=216.00KB
Metadata: total=8.00MB, used=4.00KB
# btrfs bal /btrfs
Done, had to relocate 5 out of 5 chunks
# btrfs fi
2011 Apr 09
16
wrong values in "df" and "btrfs filesystem df"
Hallo, linux-btrfs,
First I create an array of 2 disks with
mkfs.btrfs -d raid0 -m raid1 /dev/sdb1 /dev/sdd1
and mount it at /srv/MM.
Then I fill it with about 1,6 TByte.
And then I add /dev/sde1 via
btrfs device add /dev/sde1 /srv/MM
btrfs filesystem balance /srv/MM
(it run about 20 hours)
Then I work on it, copy some new files, delete some old files - all
works well. Only
df
2012 May 07
53
kernel 3.3.4 damages filesystem (?)
Hallo,
"never change a running system" ...
For some months I run btrfs unter kernel 3.2.5 and 3.2.9, without
problems.
Yesterday I compiled kernel 3.3.4, and this morning I started the
machine with this kernel. There may be some ugly problems.
Copying something into the btrfs "directory" worked well for some files,
and then I got error messages (I''ve not
2010 Nov 22
9
btrfs problems and fedora 14
I thought I would try btrfs on a new installation of f14. yes, I know
its experimental but stable so it seemed to be a good time to try it.
I am not sure if I have missed something out of all my searching but am
I correct in thinking that currently:
I. it is not possible to boot from a snapshot of the operating
system and, in particular, the yum snapshots cannot be used for
2012 Jan 17
8
[RFC][PATCH 1/2] Btrfs: try to allocate new chunks with degenerated profile
If there is no free space, the free space allocator will try to get space from
the block group with the degenerated profile. For example, if there is no free
space in the RAID1 block groups, the allocator will try to allocate space from
the DUP block groups. And besides that, the space reservation has the similar
behaviour: if there is no enough space in the space cache to reserve, it will
reserve
2012 Feb 07
2
Understanding Default RAID Behavior
The Wiki does not make it clear as to why adding a secondary device
defaults to RAID1 metadata and RAID0 data. I bought two SSDs with the
intention of doing a BTRFS RAID0 for my root.
What is the difference between forcing RAID0 on metadata and data as
opposed to the default behavior? Can anyone clarify that?
Thank you for your time,
Mario
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2010 Dec 01
12
Fsck, parent transid verify failed
Hi folks!
Been using btrfs for quite a while now, worked great until now.
Got power-loss on my machine and now i have the "parent transid verify
failed on X wanted X found X" problem.
So I can''t get it to mount.
My btrfs is spread over sda (2tb), sdc(2tb), sdd(1tb).
Is this something that an offline fsck could fix ?
If so is the fsck-util being developed ?
Is there a way to
2011 Aug 08
7
“bio too big” regression and silent data corruption in 3.0
tl;dr version: 3.0 produces “bio too big” dmesg entries and silently
corrupts data in “meta-raid1/data-single” configurations on disks with
different max_hw_sectors, where 2.6.38 worked fine.
tl;dr side-issue: on-line removal of partitions holding “single” data
attempts to create raid0 (rather than single) block groups. If it can''t
get enough room for raid0 over all remaining disks, it
2013 Jan 05
14
/boot as a btrfs subvolume
As of the latest updates to anaconda and grub2 for Fedora 18, it is now
possible to install with /boot as a btrfs subvolume. The way that grub2
is handling this is the "reach down" to the files it needs as if the
subvolume was a directory.
Is this OK?
At this point I am not worried about snapshots or any other
complexities. If the subvolume name is known. should grub2 be able to
2013 Jun 26
1
some feedbacks seen on btrfs
First off, thanks for an awesome file system, it is working well for
my purposes of compressing a filesystem on a small VPS. Woot!
I thought I''d call out a few things (in the hopes of spurring
improvements) I''d seen about btrfs (in case they weren''t common
knowledge...):
2009 Nov 19
10
Unable to mount loopback devices in RAID mode
Hi!
I recently tried to mount a filesystem in RAID1 mode using loopback devices. I followed the instructions at [1]. Here''s exactly what I''ve done:
$ dd if=/dev/zero of=raid1_0.img bs=1M count=500
$ dd if=/dev/zero of=raid1_1.img bs=1M count=500
$ mkfs.btrfs -m raid1 -d raid1 raid1_0.img raid1_1.img
$ losetup /dev/loop0 raid1_0.img
$ losetup /dev/loop1 raid1_1.img
$ mount -t
2012 Jan 26
13
btrfs-raid questions I couldn't find an answer to on the wiki
I''m currently researching an upgrade to (raid1-ed) btrfs from mostly
reiserfs (which I''ve found quite reliable (even thru a period of bad ram
and resulting system crashes) since data=ordered went in with 2.6.16 or
whatever it was. (Thanks, Chris! =:^)) on multiple md/raid-1s. I have
some questions that don''t appear to be addressed well on the wiki, yet,
or where
2013 Jan 30
8
RAID 0 across SSD and HDD
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I''ve been unable to find anything definitive about what happens if I use
RAID0 to join an SSD and HDD together with respect to performance
(latency, throughput). The future is obvious (hot data tracking, using
most appropriate device for the data, data migration).
In my specific case I have a 250GB SSD and a 500GB HDD, and about 250GB of
2012 Mar 25
3
attempt to access beyond end of device and livelock
Hi Dongyang, Yan,
When testing BTRFS with RAID 0 metadata on linux-3.3, we see discard
ranges exceeding the end of the block device [1], potentially causing
dataloss; when this occurs, filesystem writeback becomes catatonic due
to continual resubmission.
The reproducer is quite simple [2]. Hope this proves useful...
Thanks,
Daniel
--- [1]
attempt to access beyond end of device
ram0: rw=129,
2011 Jan 18
6
BUG while writing to USB btrfs filesystem
While untar''ing an image to an sd card via a reader, I got the
following bug. The system also has a btrfs root, and a whole swath of
processes went into uninterruptable sleep. I was able to poke around
via ssh and sysrq, and already had netconsole set up to capture the
bug.
Root fs is on /dev/sdi1, and /dev/sdj2 is the card reader which was
the target of the untar.
[29571.448889] sd