Hi all,
I try to defrag my btrfs root partition (run by root privilege)
find / -type f -o -type d -print0 | xargs --null --no-run-if-empty btrfs
filesystem defragment -t $((32*1024*1024))
1. This kind of error messages is prompted:
failed to open /bin/bash
open:: Text file busy
total 1 failures
failed to open /lib64/ld-2.15.so
open:: Text file busy
total 1 failures
failed to open /sbin/agetty
open:: Text file busy
failed to open /sbin/btrfs
open:: Text file busy
failed to open /sbin/dhclient
open:: Text file busy
failed to open /sbin/init
open:: Text file busy
failed to open /sbin/udevd
It seems that locked files cannot be defragged, is it expected behaviour?
2. Btrfs Wiki mentions that defrag directory will defrag metadata, is
symlink/hardlink considered as metadata?
P.S. inline data is already disabled by "max_inline=0"
3. Is any possible to online defrag a btrfs partition without hindered by mount
point/polyinstantied directories?
Thank you.
ching
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On Tue, Oct 30, 2012 at 5:47 AM, ching <lsching17@gmail.com> wrote:> Hi all, > > I try to defrag my btrfs root partition (run by root privilege) > > find / -type f -o -type d -print0 | xargs --null --no-run-if-empty btrfs filesystem defragment -t $((32*1024*1024)) > > > 1. This kind of error messages is prompted: > > failed to open /bin/bash > open:: Text file busy > total 1 failures > failed to open /lib64/ld-2.15.so > open:: Text file busy > total 1 failures > failed to open /sbin/agetty > open:: Text file busy > failed to open /sbin/btrfs > open:: Text file busy > failed to open /sbin/dhclient > open:: Text file busy > failed to open /sbin/init > open:: Text file busy > failed to open /sbin/udevd > > It seems that locked files cannot be defragged, is it expected behaviour?I can''t reproduce that behaviour here, although maybe you''re running an older kernel with some bug that''s since been fixed?> 2. Btrfs Wiki mentions that defrag directory will defrag metadata, is symlink/hardlink considered as metadata? > > P.S. inline data is already disabled by "max_inline=0"Well, that''s a silly thing to do, causing every small file to take up a separate 4kb block rather than its size * 2, and requiring extra seeks to read/write them (i.e., if you have a million 10 byte files, they''ll now take up 4GB instead of 20MB).> 3. Is any possible to online defrag a btrfs partition without hindered by mount point/polyinstantied directories?If you''re asking if you can defrag an unmounted btrfs, not at this time. It''s possible in principle, nobody has cared enough to implement it yet. -- 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
On 10/30/2012 08:08 PM, cwillu wrote:> On Tue, Oct 30, 2012 at 5:47 AM, ching <lsching17@gmail.com> wrote: >> Hi all, >> >> I try to defrag my btrfs root partition (run by root privilege) >> >> find / -type f -o -type d -print0 | xargs --null --no-run-if-empty btrfs filesystem defragment -t $((32*1024*1024)) >> >> >> 1. This kind of error messages is prompted: >> >> failed to open /bin/bash >> open:: Text file busy >> total 1 failures >> failed to open /lib64/ld-2.15.so >> open:: Text file busy >> total 1 failures >> failed to open /sbin/agetty >> open:: Text file busy >> failed to open /sbin/btrfs >> open:: Text file busy >> failed to open /sbin/dhclient >> open:: Text file busy >> failed to open /sbin/init >> open:: Text file busy >> failed to open /sbin/udevd >> >> It seems that locked files cannot be defragged, is it expected behaviour? > I can''t reproduce that behaviour here, although maybe you''re running > an older kernel with some bug that''s since been fixed?I am running Gentoo with Kernel 3.6.3 x64, btrfs-progs git version my root is mounted with noatime,space_cache,inode_cache,metadata_ratio=15,max_inline=0,ssd_spread>> 2. Btrfs Wiki mentions that defrag directory will defrag metadata, is symlink/hardlink considered as metadata? >> >> P.S. inline data is already disabled by "max_inline=0" > Well, that''s a silly thing to do, causing every small file to take up > a separate 4kb block rather than its size * 2, and requiring extra > seeks to read/write them (i.e., if you have a million 10 byte files, > they''ll now take up 4GB instead of 20MB).this is off-topic to my question.>> 3. Is any possible to online defrag a btrfs partition without hindered by mount point/polyinstantied directories? > If you''re asking if you can defrag an unmounted btrfs, not at this > time. It''s possible in principle, nobody has cared enough to > implement it yet. >-- 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
On Tue, Oct 30, 2012 at 07:47:28PM +0800, ching wrote:> failed to open /bin/bash > open:: Text file busyThat''s not a btrfs problem, you can''t directly modify an executable that is being used.> failed to open /lib64/ld-2.15.so > failed to open /sbin/agetty > failed to open /sbin/btrfs > failed to open /sbin/dhclient > failed to open /sbin/init > failed to open /sbin/udevdlibraries, currently executed progs or daemons> It seems that locked files cannot be defragged, is it expected behaviour?Yes.> 2. Btrfs Wiki mentions that defrag directory will defrag metadata, is symlink/hardlink considered as metadata? > P.S. inline data is already disabled by "max_inline=0"Both -links are metadata and also stored inside metadata blocks without any chance to move to data blocks, so max_inline does not affect this.> 3. Is any possible to online defrag a btrfs partition without hindered by mount point/polyinstantied directories?Sorry, I do not understand the question. david -- 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
>> It seems that locked files cannot be defragged, is it expected behaviour? > Yes.but i am defragging a file, not modify it.>> 2. Btrfs Wiki mentions that defrag directory will defrag metadata, is symlink/hardlink considered as metadata? >> P.S. inline data is already disabled by "max_inline=0" > Both -links are metadata and also stored inside metadata blocks without > any chance to move to data blocks, so max_inline does not affect this.thank you for your explanation.>> 3. Is any possible to online defrag a btrfs partition without hindered by mount point/polyinstantied directories? > Sorry, I do not understand the question. >when a device is mounted under a directory, files in the directory is "hidden", and files in the device is "available", right? when a directory is polyinstantied, files in the original directory is "hidden", and files in the polyinstantied directory is "available", How to get past them and pass those "hidden" files to defrag command? ching -- 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
On Thu, Nov 01, 2012 at 05:17:04AM +0800, ching wrote:> >> 3. Is any possible to online defrag a btrfs partition without hindered by mount point/polyinstantied directories? > > Sorry, I do not understand the question. > > when a device is mounted under a directory, files in the directory is "hidden", and files in the device is "available", right? > when a directory is polyinstantied, files in the original directory is "hidden", and files in the polyinstantied directory is "available", > > How to get past them and pass those "hidden" files to defrag command?I hope I get it right, so unless you have a reference to the directory with hidden files (using your term), there''s no way to access them. And this is a more generic question, not related to btrfs itself. The hidden files may also belong to a different filesystem. david -- 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
On 11/06/2012 06:57 AM, David Sterba wrote:> On Thu, Nov 01, 2012 at 05:17:04AM +0800, ching wrote: >>>> 3. Is any possible to online defrag a btrfs partition without hindered by mount point/polyinstantied directories? >>> Sorry, I do not understand the question. >> when a device is mounted under a directory, files in the directory is "hidden", and files in the device is "available", right? >> when a directory is polyinstantied, files in the original directory is "hidden", and files in the polyinstantied directory is "available", >> >> How to get past them and pass those "hidden" files to defrag command? > I hope I get it right, so unless you have a reference to the directory > with hidden files (using your term), there''s no way to access them. And > this is a more generic question, not related to btrfs itself. The hidden > files may also belong to a different filesystem. > > david >thank for your explanation ching -- 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
David Sterba wrote (ao):> On Thu, Nov 01, 2012 at 05:17:04AM +0800, ching wrote: > > when a device is mounted under a directory, files in the directory > > is "hidden", and files in the device is "available", right? when a > > directory is polyinstantied, files in the original directory is > > "hidden", and files in the polyinstantied directory is "available", > > > > How to get past them and pass those "hidden" files to defrag > > command? > > I hope I get it right, so unless you have a reference to the directory > with hidden files (using your term), there''s no way to access them. > And this is a more generic question, not related to btrfs itself. The > hidden files may also belong to a different filesystem.What Ching means (I think), is that if you have directories in /home, and you mount a device onto /home, you cannot see the original directories in /home anymore. You can still access them though, with a ''mount -o bind'': # mount -o bind / /mnt # ls /mnt/home Sander -- 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