similar to: Re: BTRFS: Unbelievably slow with kvm/qemu

I''m running into a situation where I can''t unmount a mounted snapshot. It shows "busy" even though neither lsof nor fuser show any open files. Umount -f doesn''t work although umount -l does. Is there anything else I can do to debug this scenario or to clear the busy status myself? Or am I down to rebooting each time? This is on stock ubuntu-10.04, x86.

Is there a limit to the number of snapshots that can exist on a file system concurrently? Did I read something here recently about a limit to the number of paths by which a file could be known? If there are limits, then what happens when I bump into or exceed that limit? --rich -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to

On Sun, Feb 21, 2010 at 8:40 AM, Goffredo Baroncelli <kreijack@gmail.com> wrote: >       filesystem resize [+/-]<size>[gkm]|max <filesystem> -filesystem resize [+/-]<size>[gkm]|max <filesystem> +filesystem resize [+/-]<size>[gkm]|max <dev> This command works on devices, not paths. >              Resize a filesystem identified by <path>.  The

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''m looking to try BTRFS on a SSD, and I would like to know what SSD optimizations it applies. Is there a comprehensive list of what ssd mount option does? How are the blocks and metadata arranged? Are there options available comparable to ext2/ext3 to help reduce wear and improve performance? Specifically, on ext2 (journal means more writes, so I don''t use ext3 on SSDs,

Hi, If i set strict allocate = yes in samba to speed up the transfer of a mssql database dump, then btrfs does not compress the file. I have tried it also by just copying a small file in Windows to the samba share and the same. I have tried btrfs mount options autodefrag and then btrfs fi defrag -c and the file still does not get compressed. I have tried kernels 3.6.11, 3.8 and 3.10.7 on FC16

What are the recommendations for running KVM images on BTRFS systems using kernel 3.4?  I saw older posts on the web complaining about poor performance, but I know a lot of work has gone into btrfs since then.  There also seemed to be the nocow option, but I didn''t find anything that said it actualy helped. Anybody have ideas? Thanks, Matt -- To unsubscribe from this list: send the line

To reproduce the bug: # mount -o nodatacow /dev/sda7 /mnt/ # dd if=/dev/zero of=/mnt/tmp bs=4K count=1 1+0 records in 1+0 records out 4096 bytes (4.1 kB) copied, 0.000136115 s, 30.1 MB/s # dd if=/dev/zero of=/mnt/tmp bs=4K count=1 conv=notrunc oflag=direct dd: writing `/mnt/tmp'': Input/output error 1+0 records in 0+0 records out btrfs_ordered_update_i_size() may return

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

I have a 3 disk raid1 filesystem mounted with nodatacow. I have a folder in said filesystem with the ''C'' NOCOW & ''Z'' Not_Compressed flags set for good measure. I then copy in a large file and proceed to make random modifications. Filefrag shows no additional extents created, good so far. A big thank you to the those devs who got that working. However, after

Hi Seto, please could you update also the man page too ? Why it was not provided a way to clear a *single* flag ? To me it seems a bit too long to clear all the flag (btrfs mount-option clear) and then set the right one. As user interface I suggest something like chmod: btrfs mount-option set +ssd,skip_balance -nodatacow /dev/sdX or btrfs mount-option set =ssd,skip_balance,nodatacow

Hello, Trying to put together a list of TODO items for btrfs so we can update the wiki page fully. So far these things are on the list * Proper ENOSPC handling * O_DIRECT support (without checksumming) * AIO support * Subvolume quotas and inherited space usage information * Snapshot removal * QA Suite for automated regression testing * Reserved space for online fsck and the ability to add

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

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, This is updated version of nodatacow patch. To check whether a given file extent is referenced by multiple snapshots, the checker walks down the fs tree through dead root and checks all tree blocks in the path. We can easily detect whether a given tree block is directly referenced by other snapshot. We can also detect any indirect reference from other snapshot by checking

I've had the chance to use a testsystem here and couldn't resist running a few benchmark programs on them: bonnie++, tiobench, dbench and a few generic ones (cp/rm/tar/etc...) on ext{234}, btrfs, jfs, ufs, xfs, zfs. All with standard mkfs/mount options and +noatime for all of them. Here are the results, no graphs - sorry: http://nerdbynature.de/benchmarks/v40z/2009-12-22/ Reiserfs

I've had the chance to use a testsystem here and couldn't resist running a few benchmark programs on them: bonnie++, tiobench, dbench and a few generic ones (cp/rm/tar/etc...) on ext{234}, btrfs, jfs, ufs, xfs, zfs. All with standard mkfs/mount options and +noatime for all of them. Here are the results, no graphs - sorry: http://nerdbynature.de/benchmarks/v40z/2009-12-22/ Reiserfs

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

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, this shown up today. I had to do a hard reboot as graceful hanged on sync(). ------------[ cut here ]------------ kernel BUG at fs/btrfs/delayed-inode.c:1466! invalid opcode: 0000 [#1] SMP CPU 10 Modules linked in: btrfs zlib_deflate lzo_compress ipmi_devintf autofs4 be2iscsi iscsi_boot_sysfs ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_addr iscsi_tcp bnx2i cnic uio ipv6 cxgb3i libcxgbi