similar to: Permissions model for btrfs?

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:

Add the missing usage for No_COW since we''ve supported No_COW flag. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> --- misc/chattr.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/misc/chattr.c b/misc/chattr.c index 141ea6e..24254cc 100644 --- a/misc/chattr.c +++ b/misc/chattr.c @@ -83,7 +83,7 @@ static unsigned long sf; static void usage(void) {

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

Add the missing usage for No_COW since we''ve supported No_COW flag. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> --- v1->v2: sort options alphabetically, thanks to Roman Mamedov. misc/chattr.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/misc/chattr.c b/misc/chattr.c index 141ea6e..24254cc 100644 --- a/misc/chattr.c +++ b/misc/chattr.c @@ -83,7

Enabling compression via chattr +c works with ZLIB (default method) only, right? Since there is no way to specify a compression method. Cannot I use LZO this way? Thanks in advance, -- w -- 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 http://vger.kernel.org/majordomo-info.html

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

Hi, After reading through the btrfs documentation I''m curious to know if it''s possible to ever securely erase a file from a btrfs filesystem (or ZFS for that matter). On non-COW filesystems atop regular HDDs one can simply overwrite the file with zeros or random data using dd or some other tool and rest assured that the blocks which contained the sensitive information have

I just setup a new SSD with my laptop root filesystem, and at the time I though, "eh, I''ll just use zlib compression during the first copy, and then switch to lzo afterwards to maintain write speed when I''m using the laptop after the copy and reboot". Now, I rebooted with the new ssd and zlib compressed rootfs, and it seemed to boot slower than it did before with 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

Makes btrfs_ioctl_setflags return -ENOSPC and other errors when necessary. Signed-off-by: Sean Bartell <wingedtachikoma@gmail.com> --- I ran chattr -R on a full FS and btrfs crashed. This overlaps with the patch series being worked on by Jeff Mahoney. fs/btrfs/ioctl.c | 17 ++++++++++++----- 1 files changed, 12 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/ioctl.c

Hi, I''ve been running btrfs on one of my machines for a few months now but I keep hitting performance issues. My system quite frequently freezes due to IO starvation. Looking at iotop it tends to show the large majority of the disk I/O being taken up with various btrfs tasks peeking at 7-8M/s, namely: btrfs-endio-wri btrfs-delayed-m btrfs-transacti btrfs-cleaner

----- 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

We run a third party application that creates an inordinate amount of subdirectories in a single directory. To speed up I/O, I wanted to set the T attribute on the directory that will hold the subdirectories. The "chattr +T /usr/local/lepus-bb/a-0607" command returns status 0, but when I verify the setting, the attribute isn't there: # lsattr -d /usr/local/lepus-bb/a-0607

Currently compression and I assume if encryption is implemented it is turned on or off during mount. There are however many times when a user may want to select which files/directories they want to compress or encrypt. This will also be helpful when implementing btrfs support in grub for example. We can say the disk can be compressed/encrypted except for /boot so compression/encryption

Hello folks, I reported a bug here: https://bugzilla.kernel.org/show_bug.cgi?id=63071 but I am not sure if that was the right thing to do. This is producing OOM issues and leading to system crashes (including eventual panics) with such alarming frequency that I wonder if perhaps there is something different about my setup than others. In a nutshell, I originally made the mistake of storing a

Hi, I have a home server on Linux Arch (kernel 3.11.2) that uses multi-device btrfs on root filesystem. Until recently it worked completely fine. And yesterday I rebooted it and the machine did not wake up. I booted from a USB (kernel 3.10) and tried to mount the filesystem. Here is OOPs I see [ 41.676217] device fsid 25e6a6fa-fe1f-4be5-a638-eeac948f8c21 devid 8 transid 164237 /dev/sda [

Arter managing to build Samba 4.1.5 on Solaris 10 i386. I tried to join an existing Windows 2000 Server Active Directory domain as an additional domain controller. The join started to work and then died with the error: Error: Samba was compiled without the posix ACL support that s3fs requires. Try installing libacl1-dev or libacl-devel, then re-run configure and make. I downloaded acl-2.2.52 and

Postfix <http://www.postfix.org> does a chattr +S on its spool directory when it is installed on Linux. This is what is written in the postfix startup script -- # # LINUX by default does not synchronously update directories - # that's dangerous for mail. # if [ -f /usr/bin/chattr ] then CHATTR="/usr/bin/chattr +S" else CHATTR=echo fi -- Is this still required on ext3 ?

You can try chattr? https://en.wikipedia.org/wiki/Chattr 2017-10-01 12:26 GMT-03:00 Alexander Dalloz <ad+lists at uni-x.org>: > Am 01.10.2017 um 17:21 schrieb hw: > >> Hi, >> >> how can I prevent files/directories like /var/run/mariadb from being >> deleted on reboot? Lighttpd has the same problem. >> >> This breaks services and makes servers

Hi, I try to format a USB memory with a Btrfs. I can format it with mkfs.btrfs without problems. But; when I try to mount it, it fails to mount with the below error messages. But the USB memory works fine with other filesystems (ext4, XFS etc.). So, the hardware is not faulty. tarkane@tarkane:~$ sudo mkfs.btrfs -d single -n 4096 /dev/sdb1 WARNING! - Btrfs v0.18-26-g0030f1d IS EXPERIMENTAL