similar to: Finding the holes in sparse files.

Hi, We are trying to use OCFS2 as VM storage. After running into problems with qemu's disk_mirror feature we now think there could be a problem with the FIEMAP ioctl in OCFS2. As far as I understand the situation looks like this: Qemu inquiries the FS if the given section of the image is already allocated via the FIEMAP ioctl [1] It especially checks if fm_mapped_extents is greater 0.

https://bugzilla.samba.org/show_bug.cgi?id=11588 Bug ID: 11588 Summary: missing option: preallocate for all files except for sparse Product: rsync Version: 3.1.2 Hardware: x64 OS: Linux Status: NEW Severity: enhancement Priority: P5 Component: core

Hi, I need to understand and to calculate the offset of the beginning of a file within my partition which uses an ext3 filesystem. Can I use dumpe2fs to figure that out, if yes how? Sincerely, William Tambe

Hi! Today I converted my /home from Ext4 to BTRFS by reformatting and copying all over again. I created the filesystem with -l 16384 -n 16384 -d single -m single on an logical volume Intel SSD 320 and mount with compress=lzo,spacecache. Current state: merkaba:~> btrfs filesystem show failed to read /dev/sr0 Label: ''home'' uuid: […] Total devices 1 FS bytes used

Hi, how can I do the following in a shell script: - check whether my file system supports cp --reflink? - check whether two files share the same data on disk, i.e. one has been created by cp --reflink of the other? Thank you! Thomas Koch -- 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

It seems to me that it should be possible to make --inplace and --sparse compatible. The manpage says -S, --sparse ... Conflicts with --inplace because it's not possible to overwrite data in a sparse fashion. but I think it _is_ possible to do that, provided the receiving side opens the dest file read-write instead of write-only. When writing within the existing

Hi, I need clarifications on how to sell linux tools. (Though i' not sure how people ready to buy it :) ) I have written few tools and planning to write more(by giving up current non-linux & boring job). I want to know,which license will allow me to sell tools/softwares? (I hope to sell the products through online) Cheers, Lakshmipathi.G www.giis.co.in

When designing a filesystem, is fragmentation really an issue if access to the disk can be done using scatter-gather DMA techics ?

Hi all, I plan on having about 100M files totaling about 8.5TiBytes. To see how ext3 would perform with large numbers of files I've written a test program which creates a configurable number of files into a configurable number of directories, reads from those files, lists them and then deletes them. Even up to 1M files ext3 seems to perform well and scale linearly; the time to execute

Hi Steven, Hi ext3-users list! We encountered a reproduceable problem with ext3: When issuing a FIBMAP ioctl for a block written right before while the FS is under high load (RH build universe), the assertion !journal->j_running_transaction fails at the bottom of journal_flush() in fs/jbd/journal.c. We encountered this problem with the arch=s390x (64 bit big endian) bootloader zipl, I'll

While exploring some btrfs maintenance with respect to defragmenting I ran the following commands: # filefrag /path/to/34G.file /path/to/5.7G.file /path/to/34G.file: 2406 extents found /path/to/5.7G.file: 572 extents found Thinking those mostly static files could be less fragmented I ran: # btrfs filesystem defragment -c /path/to/34G.file # btrfs filesystem defragment -c /path/to/5.7G.file and

Hi folks, I''m using Ubuntu 12.10 Quantal with # uname -r 3.5.0-24-generic And it seems I cannot defrag : # filefrag /boot/initrd.img-3.5.0-24-generic /boot/initrd.img-3.5.0-24-generic: 3 extents found # btrfs filesystem defrag /boot/initrd.img-3.5.0-24-generic # echo $? 20 # filefrag /boot/initrd.img-3.5.0-24-generic /boot/initrd.img-3.5.0-24-generic: 3 extents found Any clue

Hello, Does anybody know how to avoid the file fragmentation when a file is created over NFSv3? A file created locally is OK: dd bs=32k if=/dev/zero of=test count=32x1024 conv=fsync filefrag test test: 10 extents found, perfection would be 9 extents When I create the file in the same dir, but from another machine, mounted over NFS: filefrag test test: 4833 extents found, perfection would be

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

https://bugzilla.samba.org/show_bug.cgi?id=8918 Summary: Use fiemap to quickly detect zero ranges of source file Product: rsync Version: 3.1.0 Platform: All OS/Version: All Status: NEW Severity: enhancement Priority: P5 Component: core AssignedTo: wayned at samba.org

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

----- 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

On Sat, Nov 7, 2015 at 5:03 AM, Richard W.M. Jones <rjones@redhat.com> wrote: > How about 'strace mkfs.ext2 ..' and see if any system calls are > returning errors. That would show you whether nbd-client is throwing > errors away, or whether mkfs is getting the errors and ignoring them > (seems pretty unlikely, but you never know). > > After that, it'd be down

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 All, I''d like to know if there is an utility like `Filefrag'' shipped with e2fsprogs on linux, which is used to fetch the extents mapping info of a file(especially a sparse file) located on ZFS? I am working on efficient sparse file detection and backup through lseek(SEEK_DATA/SEEK_HOLE) on ZFS, and I need to verify the result by comparing the original sparse file and