similar to: KVM on top of BTRFS

Hello, is it possible to set nodatacow on a per-file basis? I couldn''t find anything. If not, wouldn''t that be a great feature to get around the performance issues with VM and database storage? Of course cloning should still cause COW. Thanks, Ralf-Peter -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to

I set the C (NOCOW) and z (Not_Compressed) flags on a folder but the extent counts of files contained there keep increasing. Said files are large and frequently modified but not changing in size. This does not happen when the filesystem is mounted with nodatacow. I''m using this as a workaround since subvolumes can''t be mounted with different options simultaneously. ie. one with

Hi, I have 4 machines, all converted to BTRFS about 6 months ago, now all running Ubuntu Quantal with kernel 3.5.0-17 The matter is that all these machines are now getting slower and slower everyday, every disk access causing the disk to be 100% busy for long periods, to the point that I''m now seriously considering migrating everything back to ext4... From the start BTRFS was "not

----- Forwarded Message ----- From: "Stefan Hajnoczi" <stefanha@redhat.com> To: "Eric Sandeen" <sandeen@redhat.com> Cc: virt-devel@redhat.com, "Kevin Wolf" <kwolf@redhat.com> Sent: Friday, November 22, 2013 9:20:51 AM Subject: [virt-devel] btrfs NOCOW for VM disk images Hi, In upstream QEMU we''re discussing patches that set the NOCOW flag

Hi, I am using 2.6.36.3 kernel with btrfs, 512MB memory and a very slow disk, no special options for mounting btrfs except noatime. Now I found it very slow. When I rm a 5GB movie, it took 20 secs. -- 竹密岂妨流水过 山高哪阻野云飞 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at

Hi all, i am new on btrfs, i am testing KVM on btrfs (host: kernel x86-64 3.5.3), the performance is reasonable. I have two question on defrag, can someone help me? 1. According to btrfs wiki, defragment a COW file will produce two unrelated files. Does it apply to the "autodefrag" mount option? 2. Is there any command for the fragmentation status of a file/dir ? e.g. fragment

Kernel 3.1-rc8 btrfs-progs-0.19 mount options: noatime,autodefrag (space_cache is enabled) There are snapshots present on the filesystem. When I do a btrfs fi defrag on a file, the file becomes much more fragmented. The end result can be a file with 20k times more fragments than before. Initially I thought the extents were just smaller but were next to each other, so I checked with both

Hello list, i know what btrfs don''t support swap files. I read arch wiki and when i reading about systemd addon for auto create swapfile on btrfs, i invent the way, how create and using swap file, just see following sh code: swapfile=$(losetup -f) #free loop device truncate -s 8G /swap #create 8G sparse swap file losetup $swapfile /swap #mount file to loop mkswap $swapfile swapon

Hello, some time ago we discussed on #btrfs that the nocow attribute for files wasn''t working (around 3.3 or 3.4 kernels). That was evident by files fragmenting even with the attribute set. Chris mentioned to find a fix quickly for that, and posted some lines of change into irc. But recently someone mentioned that 3.6-rc looks like still not respecting nocow for files. Is there really

Hi, I''m trying to convert two ext4 FS to btrfs, but I''m surprised by the time needed to do that conversion. The first FS is on a 500GiB block device, and btrfs-convert is running since more than 48h : root 1978 25.6 47.7 748308 732556 ? D Feb18 944:44 btrfs-convert /dev/vg-backup/backup The second is on a 340GiB block device, and the processing time is similar

Hi, I''ve been using btrfs for my root partition for about a month on archlinux and recently Ive started using the i3 window manager and starting X manually and I now boot to run level 3 (multi-user.target for systemd) and Ive noticed that booting archlinux on a btrfs root, there is a lot off hdd chatter after the login prompts are displayed, which doesnt happen with ext4 on root, so I

Balance will create reloc_root for each fs root, and it''s going to record last_snapshot to filter shared blocks. The side effect of setting last_snapshot is to break nocow attributes of files. So it turns out that checking last_snapshot does not always ensure that a node/leaf/file_extent is shared. That''s why shared node/leaf needs to search extent tree for number of

sorry forgot to follow the protocol, now included RFC in the subject. Hi, Appears that no one is working on the auto-snapshot feature for btrfs, so here I am implementing the same. Below is a draft on the feature list. Any comments / questions / suggestions are welcome, please do let me know. btrfs auto snapshot feature will include: Initially: - configurable timely

Glück Auf! I use now kernel 3.2. The filesystem was originally created under 2.6.39 on 1 whole hdd, mounted with "noatime,nodiratime,inode_cache". I use it for backups: rsync the whole system to a subvolume, snapshot it and then delete some tempfiles in the snapshot, which are 90% of the full-backup, all once a day. In figures: on this 1 TB hdd is the full-backup with around 600 GiB and

What happens if you set an individual file inside a subvolume as nocow (chattr +C) and then take a snapshot of that subvolume and modify the file in both? Will btrfs now ignore the nocow attribute completely or will it do "as few copies as possible"? (I''d love to know if it''s possible to visualize the fragmentation of a single file.) -- To unsubscribe from this list:

I want to eliminate the COW feature on all of my OS files. It is a nice feature for user files, but I don''t see a clear benefit for the actual OS files. And I suspect that COW induced fragmentation is causing or aggravating problems with my system including the boot open_ctree problem. I had planned to recursively chattr these files to "nodatacow" status but then I ran

Hello all. What we have: SL6 - kernel 2.6.32-131.2.1.el6.x86_64 btrfs on mdadm RAID5 with 8 HDD - 27T partition. I see this at top: 1182 root 20 0 0 0 0 R 100.0 0.0 16:39.73 [btrfs-delalloc-] And LA is grow. What is this and how can I fix it? -- Best regards, Proskurin Kirill -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of

Hi list, I have a few large image files (VMware workstation VMDKs and TrueCrypt containers) which I routinely back up over the network to a btrfs raid10 volume via bigsync (https://code.google.com/p/bigsync/). The VM images in particular get really fragmented due to CoW, which is expected. I haven''t yet switched off CoW on the backups directory mainly to experiment and see what

After running ceph on XFS for some time, I decided to try btrfs again. Performance with the current "for-linux-min" branch and big metadata is much better. The only problem (?) I''m still seeing is a warning that seems to occur from time to time: [87703.784552] ------------[ cut here ]------------ [87703.789759] WARNING: at fs/btrfs/inode.c:2103

Good morning Btrfs list, I have been loading a btrfs file system via a script rsyncing data files from an nfs mounted directory. The script runs well but after several days (moving about 10TB) rsync reports that it is sending the file list but stops moving data because btrfs balks saying too many files open. A simple umount/mount fixes the problem. What am I flushing when I remount that