@@ Line 2: / Line 2: @@
 __TOC__
 <translate>
-=Btrfs is a modern CoW [[File_Systems|file system]]=
+=Btrfs is a modern CoW [[File_Systems|file system]]= <!--T:1-->
 A modern '''C'''opy '''o'''n '''W'''rite file system for Linux aimed at implementing advanced features while also focusing on '''fault tolerance''', '''repair''' and '''easy administration'''. Btrfs not only is a file system, but also is partly a volume manager, software-raid, backup-tool, and it is flash-friendly.
+<!--T:2-->
 Because Btrfs is different, some things seem unfamiliar and strange. If you want to learn the details and the newest stuff, then [https://btrfs.wiki.kernel.org/index.php/Main_Page btrfs.wiki.kernel.org] is the place to go or [https://btrfs.readthedocs.io/en/latest/index.html btrfs.readthedocs.io].
 Development of Btrfs started in 2007. Since that time, Btrfs is a part of the Linux kernel and is under active development. The Btrfs code base and filesystem-layout is '''[https://btrfs.wiki.kernel.org/index.php/Status stable] .''' However, new features are still under development. Its main features and benefits are:
@@ Line 12: / Line 13: @@
 *'''Auto-repair''' - checksums for data and metadata, automatic detection of silent data corruption
+<!--T:3-->
 (see [https://btrfs.wiki.kernel.org/index.php/Main_Page btrfs@kernel.org],
 [https://btrfs.readthedocs.io/en/latest/ btrfs.readthedocs.io], [https://wiki.archlinux.org/title/Btrfs Btrfs@ARC-wiki], [https://de.wikipedia.org/wiki/Btrfs Btrfs@wikipedia])
+<!--T:4-->
 <!-- TOC shows contents of the page -->__TOC__
-=== Familiar with btrfs-slang ? ===
+=== Familiar with btrfs-slang ? === <!--T:5-->
 Because Btrfs is different, you will find some words that do have a special meaning when used for btrfs. This may be a source of confusion.
+<!--T:6-->
 <div class="mw-collapsible mw-collapsed"><div class="mw-collapsible-toggle" style="float:none;">▶ Btrfs '''volume'''</div><div class="mw-collapsible-content">A '''[[Btrfs#Btrfs_Volume|volume]]''' is a pool of raw storage and consists of one or more '''device'''s. The size of the volume will be the addition of all devices that are part of this volume. In most cases you will only use one volume. You are able to add/remove devices at any time. ''Usually you do '''not''' mount a Btrfs volume.''
 </div></div>
+<!--T:7-->
 <div class="mw-collapsible mw-collapsed"><div class="mw-collapsible-toggle" style="float:none;">▶ '''chunk'''</div><div class="mw-collapsible-content">A '''chunk''' is simply a piece of storage that Btrfs can use to put data on. Think of a chunk (usually 1GiB) as of a page in a book. The book is the '''[[Btrfs#Btrfs_Volume|volume]]''', and the chunk is one page of it. When you start, all pages are empty. When you write data to the volume, one page (="chunk") after the other is written to.
 </div></div>
+<!--T:8-->
 <div class="mw-collapsible mw-collapsed"><div class="mw-collapsible-toggle" style="float:none;">▶ '''device'''</div><div class="mw-collapsible-content">A '''device''' is some linux device. It may be '''a partition''' like '''/dev/sdz1''' or /dev/sdz2. Or it may be a raw disk device like /dev/sdz without any partitioning. A Btrfs '''[[Btrfs#Btrfs_Volume|volume]]''' consists of '''at least one device'''.
 </div></div>
+<!--T:9-->
 <div class="mw-collapsible mw-collapsed"><div class="mw-collapsible-toggle" style="float:none;">▶ '''subvolume'''</div><div class="mw-collapsible-content">A Btrfs '''[[Btrfs#subvolume|subvolume]]''' is an independently mountable POSIX file-tree and '''not a block device'''. It is the part of a '''[[Btrfs#Btrfs_Volume|volume]]''' that will be '''mounted writeable''' into your Linux system. By convention the names of subvolumes start with @ ('''@''', '''@home''', '''@snapshots''' ...). All subvolumes share the space of the Btrfs volume. You may create subvolumes at will. (You may think of subvolumes ''as sort of "dynamic partitions" inside a Btrfs volume'')
 </div></div>
+<!--T:10-->
 <div class="mw-collapsible mw-collapsed"><div class="mw-collapsible-toggle" style="float:none;">▶ '''default subvolume''' </div><div class="mw-collapsible-content">The default subvolume of a Btrfs '''[[Btrfs#Btrfs_Volume|volume]]''' is special. When you mount, you normally have to name a '''[[Btrfs#subvolume|subvolume]]''' to mount. When you don't name a subvolume, the default subvolume will be used. The default subvolume can be changed to any subvolume. It is advisable to set that subvolume as default, that is used for mounting linux '''"/"''' this is often the subvolume with the name '''"@"'''
 </div></div>
+<!--T:11-->
 <div class="mw-collapsible mw-collapsed"><div class="mw-collapsible-toggle" style="float:none;">▶ Btrfs '''volume-root''' "/", Btrfs '''layout''' </div><div class="mw-collapsible-content">A '''[[Btrfs#Btrfs_Volume|volume]]''' contains one ore more '''[[Btrfs#subvolume|subvolumes]]'''. But they are not stored in form of a simple list. These subvolumes are stored in a tree-like structure like in a filesystem.  Sometimes called the "top-level subvolume" or "root of the volume". But be careful this is '''not linux-root "/"''', but Btrfs '''volume-root "/"'''. There are several basic schemas to '''layout''' subvolumes in a volume
 </div></div>
+<!--T:12-->
 <div class="mw-collapsible mw-collapsed"><div class="mw-collapsible-toggle" style="float:none;">▶ '''snapshot'''</div><div class="mw-collapsible-content">A '''[[Btrfs#snapshot|snapshot]]''' looks nearly the same as a '''[[Btrfs#subvolume|subvolumes]]'''. But don´t get confused. When we talk about snapshots we usually mean a "'''Read-Only (ro) photograph''' of a subvolume". While the subvolume changes with time. A snapshot stays in the state of the subvolume at the time we made it. You can mount snapshots into your linux system, but you only can read the content. And the content will never change while this snapshot exists. When creating '''snapshots''' you have to watch out for the Btrfs-'''layout''' in use.
 It is possible to make a writeable(rw) subvolume out of a ro-snapshot. This is the way '''[[Btrfs#Rollback_to_a_snapshot|roll back]]''' does work.
 </div></div>
+<!--T:13-->
 <div class="mw-collapsible mw-collapsed"><div class="mw-collapsible-toggle" style="float:none;">▶ Self-healing</div><div class="mw-collapsible-content">'''This is no magic.''' Because of the nature of Btrfs as '''[[Btrfs#What.27s_this_.22Copy_on_Write.22|CopyOnWrite]]''' filesystem and because of the checksums, it is possible to check the filesystem and repair some errors. This does happen silently.
+<!--T:14-->
 * [[Btrfs#RAID_0_.28not_Just_a_Bunch_of_Disks.29|Without RAID]] it is possible to correct some small faults that happen because of power outage. (This is done when the filesystem is mounted again)
 * [[Btrfs#RAID_1_.28mirrored.29.2C_1C3.2C_1C4|With RAID1]] it is possible to repair some parts of files that where damaged by faults on one device. (This is done when the file is read the next time)
 </div></div>
+<!--T:15-->
 <div class="mw-collapsible mw-collapsed"><div class="mw-collapsible-toggle" style="float:none;">▶ '''scrub'''</div><div class="mw-collapsible-content">A '''[[Btrfs#scrub|scrub]]''' is like an inspection of your car. The mechanic will look at all parts, and will tell you if something is amiss. If he finds very small problems, he will repair this automatically without asking for permission, and with minimal extra cost.
 </div></div>
+<!--T:16-->
 <div class="mw-collapsible mw-collapsed"><div class="mw-collapsible-toggle" style="float:none;">▶ '''balance'''</div><div class="mw-collapsible-content">A '''[[Btrfs#balance|balance]]''' is like renovating your home. Sometimes it is necessary to renovate a room, sometimes you will renovate your home completely. But you don't do it once in every week ;-) With balance, the furniture will be transported around and rearranged. '''You need to do this when changing RAID-levels.'''
 </div></div>
+<!--T:17-->
 You may also have a look at [https://btrfs.readthedocs.io/en/latest/Glossary.html Btrfs Glossary]
-= Volume management [https://btrfs.readthedocs.io/en/latest/Volume-management.html ⇒] =
+= Volume management [https://btrfs.readthedocs.io/en/latest/Volume-management.html ⇒] = <!--T:18-->
 A volume is a pool of raw storage. Consists of one or more devices. The size of the volume will be the addition of all included devices, unless you use RAID.
+<!--T:19-->
 If you do use more then one device, please also read the section about RAID. You are able to add/remove devices at any time to increase/decrease the size of the volume. With adding/removing devices it is also possible to move a volume from one device to another (without changing the UUID).
+<!--T:20-->
 Usually you do not mount the Btrfs volume itself, but you mount subvolumes. There may be times when it is practical to mount the Btrfs volume-root itself. Then you are able to change the volume layout. All (writeable) subvolumes inside a volume are movable inside the volume with mv. Moving subvolumes will not touch the data, but change the volume layout in an instant.
+<!--T:21-->
 When not otherwise specified, additional devices are handled as '''J'''ust a '''B'''unch '''o'''f '''D'''isks (JBOD)
 {{BoxInfo|Tip|In most cases it is advisable to use '''only one volume'''}}
-=== Extend a volume ===
+=== Extend a volume === <!--T:22-->
 This is very easy because btrfs incorporates a volume manager. You only have to look for a free device. You may use a partition like ''/dev/sdz4'' or you may use a raw device like ''/dev/sdz''. Then add this device to your existing volume with '''btrfs device add'''. You may need to do a '''balance''' afterwards to redistribute some chunks.
 {{RootCmd|command=btrfs device add [/dev/sdz4] /}}
 {{BoxWarning|Dont´t format the partition!|To add a device it should have '''NO filesystem''' on it. The btrfs volume manager will include the  free storage of the device '''into the existing filesystem'''.}}
-=== Move a volume (to another disk) ===
+=== Move a volume (to another disk) === <!--T:23-->
 There are a lot of ways you can move a "normal" filesystem from one disk to another. But there are dangers with moving btrfs volumes that do not exist with other filesystems! '''Don´t ever move a btrfs volume with a tool that does not say it is 100% btrfs-proof.'''
 When at any time there are 2 partitions in one computer that have the same filesystem UUID, one ore both filesystems '''may be destroyed'''. Under the topic '''tips''' you will find an easy way to do move a volume without any danger
@@ Line 82: / Line 100: @@
 {{BoxSuccess|Tip: move a volume|There is an easy and secure way to move a volume to another disk/device. If you use Btrfs itself to move the volume, there will be no danger. You even can do this while the volume is in use. [[Btrfs#move_a_volume|See how to in "tips"]]}}
-== Subvolume [https://btrfs.readthedocs.io/en/latest/Subvolumes.html ⇒] ==
+== Subvolume [https://btrfs.readthedocs.io/en/latest/Subvolumes.html ⇒] == <!--T:24-->
 A subvolume is an independent mountable POSIX file-tree and '''not a block device'''. It is the part of a volume that will be '''mounted writeable''' into your Linux system. If you dont´t care about snapshots, and you don´t care about backups, it would be possible to use only one subvolume for everything. But then you would not be able to use the powers of Btrfs. ''Lets assume you do care.''
+<!--T:25-->
 All subvolumes share the space of the Btrfs volume. You may create subvolumes at will. (You may think of subvolumes as sort of "dynamic partitions" inside a Btrfs volume)
+<!--T:26-->
 When making snapshots (or send/receive) every subvolume will be handled separately. For example when you have 2 subvolumes(@, @home), and make a snapshot of one of them(@), this snapshot will contain every bit of data of all files in this subvolume(@), but none of the data from the other subvolume(@home). So if you make a few subvolumes, you are able to '''follow different strategies for snapshots''' of them. And you can '''restore''' each of them '''separately'''.
+<!--T:27-->
 By convention the names of subvolumes start with '''@ (@home, @snapshots''' ...).
-=== Subvolume '''@''' ===
+=== Subvolume '''@''' === <!--T:28-->
 This is the subvolume where your '''complete manjaro system''' will reside. It is mounted at "/" in your filesystem. You may take snapshots of this subvolume (or backups with send/receive) to secure a running manjaro system. When something bad happens, you are able to rollback to one of the snapshots, or to restore one of the backups of this subvolume '''without loosing your data''' at /home.
+<!--T:29-->
 In order to make a rollback possible, this has to contain all and every data that is needed for your manjaro to work properly! This includes:
 * '''config''' of your bootloader (/boot/brub/grub.cfg)
@@ Line 106: / Line 128: @@
 * rest of system files (/usr/*)
-=== Subvolume '''@home''' ===
+=== Subvolume '''@home''' === <!--T:30-->
 This is the subvolume where all '''user data''' ist stored. When you rollback your "@", this will not change at all. You may take snapshots of /home at a different rate and for different reasons. While snapshots of "@"  are good for rollback, snapshots of @home are good for '''undeleting''' accidentally by users deleted (or overwritten) files.
-=== Subvolume '''@snapshots''', '''@home.snapshots''' ===
+=== Subvolume '''@snapshots''', '''@home.snapshots''' === <!--T:31-->
 It is wise to "store" snapshots '''NOT inside''' the subvolume they where taken from. So this may be the right place to store your snapshots of '''@''' or '''@home'''.
-=== Subvolume '''@...''' ===
+=== Subvolume '''@...''' === <!--T:32-->
 Sometimes it is desired to have other '''special snapshot strategies''' (or no snapshots at all) for some parts of the filesystem. If you need this, make another subvolume.
+<!--T:33-->
 To have access to the root(/) of your volume, you need to mount this separately. (Please do not confuse this with "/" of the file system)
 {{RootCmd|command=mount -t btrfs -o subvol=/,defaults [/dev/sdz2] /mnt}}
@@ Line 126: / Line 149: @@
 {{RootCmd|command=umount /mnt}}
-== Snapshot ==
+== Snapshot == <!--T:34-->
+<!--T:35-->
 A snapshot looks nearly the same as a subvolume. But snapshots really are "read-only photographs of a subvolume". While the subvolume changes with time. The snapshot is frozen in the state of the subvolume at the time you made it.
 A snapshot is '''read-only'''. Therefore it is guaranteed not to change. In a snapshot you will find all files of the subvolume frozen in time. A snapshot is not a substitute for a backup! {{BoxWarning|Where to place snapshots|When creating snapshots you have to watch out for the volume layout in use. [https://github.com/jrabinow/snapper-rollback see@wiki.archlinux]}}
+<!--T:36-->
 Snapshots (if regularly made) may be used for:
 * Comparing config files from different "times"
@@ Line 140: / Line 165: @@
 * ''What do you use snapshots for ?''
+<!--T:37-->
 Making and deleting snapshots is best done automatically:
 * snapper [https://wiki.archlinux.org/title/snapper snapper@wiki.archlinux] [https://github.com/openSUSE/snapper snapper@github] [http://snapper.io/ snapper.io]
 * timeshift [https://wiki.archlinux.org/title/Synchronization_and_backup_programs timeshift@wiki.archlinux] [https://github.com/teejee2008/timeshift timeshift@github]
-=== Taking snapshots ===
+=== Taking snapshots === <!--T:38-->
+<!--T:39-->
 Taking a snapshot is '''very fast''', and '''nearly priceless'''. After the snapshot is taken, all future writes will go as in CoW usual. But none of the space occupied by files in the snapshot will be reusable. As you write more and more new files, the filesystem will grow because it can not reuse the files in the snapshot. A new snapshot will freeze additionally all created or modified files since the last snapshot and so on. '''If you don´t release'''(delete) any snapshot '''you will''' eventually '''run out of space''' soon(disk full)
-=== Releasing snapshots ===
+=== Releasing snapshots === <!--T:40-->
+<!--T:41-->
 Deleting a snapshot does not delete any files that are actually in use by other snapshots or the subvolume they where taken from. To free some space, Btrfs has to test for every file in the snapshot, whether it is in use, or it is not. If it is not, the space of this file/version will become free.(This is greatly simplified) Therefore it is '''costly to remove snapshots'''. And Btrfs will do this work in the background. You may notice this, because when you delete a snapshot there will be '''no immediate gain in free space'''. After a while you will notice that some space has become free.
+<!--T:42-->
 Don´t forget to remove snapshots, or you will get in '''"out of space" -trouble soon'''. Btrfs needs some free space to manage its work. If your volume is more then 80% full you have to think(fast) what to do.
 * ++++ '''Add''' some partition/device to the volume
@@ Line 157: / Line 186: @@
 * + '''Delete''' some files (this does only help if they are not part of any snapshot)
-=== Rollback to a snapshot ===
+=== Rollback to a snapshot === <!--T:43-->
+<!--T:44-->
 If you need to roll back into a snapshot you have to replace the actual subvolume by the chosen snapshot.
 # '''Make a snapshot(ro)''' of the actual subvolume (for later reference)
@@ Line 167: / Line 197: @@
 see in forum: [https://forum.manjaro.org/t/how-to-manual-rollback-with-btrfs/80230 manual Rollback with btrfs]
+<!--T:45-->
 Please also have a look at [https://github.com/jrabinow/snapper-rollback snapper-rollback@github] and at [https://wiki.archlinux.org/title/Snapper#Suggested_filesystem_layout snapshot-layout@wiki.archlinux] for the suggested flat layout and the reasoning. ([https://forum.manjaro.org/t/how-to-manual-rollback-with-btrfs/80230 Rollback example ])
 {{BoxWarning|Don't forget to remove snapshots before you run out of space|Every time you take a snapshot you only use the "rest of the volume" for storing everything you change from this time on. At some point in time you have to release the snapshot. Don´t use your space up. Btrfs needs '''space to breath.''' Don't use more then 80% or you will get into trouble."}}
 {{BoxDanger|NO Snapshots together with quotas|There are reports about massive problems when using '''quotas''' together with snapshots (snapper, timeshift). Please have a look at: [https://btrfs.wiki.kernel.org/index.php/Quota_support#Known_issues Known_issues@btrfs.kernel.org]}}
-= Btrfs RAID =
+= Btrfs RAID = <!--T:46-->
 With Btrfs you no longer need to use ''mdadm'' to create mirrored volumes or to create RAIDs. This is already included in btrfs, and very easy to use. There are even advanced features bult in:
 * Add devices to the volume This will integrate a device into the mounted volume {{RootCmd|command=btrfs device add [/dev/sdz7] /}}
@@ Line 180: / Line 211: @@
 * Do this while the volume is mounted and being used
+<!--T:47-->
 see [https://en.wikipedia.org/wiki/RAID RAID@wikipedia]
-== RAID 0 (not Just a Bunch of Disks)==
+== RAID 0 (not Just a Bunch of Disks)== <!--T:48-->
 Using one ore more devices to build a volume. This volume has the '''capacity of all the used devices together(1+2+3+4...)'''. This is an very easy way to expand your volume when you need more space.  You even can add 2 or 3 devices at a time. When you want to replace a device, you can add the new device, then remove the old device. Btrfs will move all data as necessary. ''To distribute all data to all devices you may want to '''balance''' the volume.'' Btrfs will stripe the data to all devices.
 {{BoxWarning|If one device fails, everything is lost|Be aware that when one of the devices fails your complete volume may be lost if you use RAID 0}}
-=== 1 device ===
+=== 1 device === <!--T:49-->
 In most setups you will start a volume with 1 device. If only one device is present, '''metadata will be duplicated''' on that device. Even with this simple setup you benefit from most features of Btrfs.
-=== 2 or more devices ===
+=== 2 or more devices === <!--T:50-->
 By default, '''metadata will be mirrored''' across two devices and '''data will be striped''' across all of the devices present. But if you have 2 or more devices in your volume you should consider using RAID 1.
-== RAID 1 (mirrored), 1C3, 1C4 ==
+== RAID 1 (mirrored), 1C3, 1C4 == <!--T:51-->
+<!--T:52-->
 When using Raid 1 btrfs mirrors data and metadata. This way it is possible to repair data when one copy gets damaged. This could happen when one device fails, when power was lost while writing, ... '''After enabling RAID1''' all new data and metadata is automatically mirrored. To mirror your existing data and metadata, '''you have to balance your complete volume'''.
-=== Automatic repair ===
+=== Automatic repair === <!--T:53-->
 In order to preserve the integrity of the volume, Btrfs does separate CRC-checksums of metadata blocks and of data blocks. Every time a data block is read, the checksum is verified. When the checksum shows that the data is not good, Btrfs tries to get a good copy from the mirrored block. Then the bad block is written again with the good data from the mirrored block. This happens in background. The filesystem has been repaired, and this is logged into syslog. This can be forced by using btrfs scrub.
-=== RAID 10 (automatic) ===
+=== RAID 10 (automatic) === <!--T:54-->
 When using enough devices(4...) with RAID 1, Btrfs will distribute all data, so that it not only is mirrored but also striped.
-== RAID 5 ==
+== RAID 5 == <!--T:55-->
 {{BoxDanger|Not save yet|This is not recommended [https://btrfs.wiki.kernel.org/index.php/Gotchas see Parity RAID@btrfs.wiki.kernel.org]}}
-== RAID 6 ==
+== RAID 6 == <!--T:56-->
 {{BoxDanger|Not save yet|This is not recommended [https://btrfs.wiki.kernel.org/index.php/Gotchas see Parity RAID@btrfs.wiki.kernel.org]}}
-= Btrfs maintenance =
+= Btrfs maintenance = <!--T:57-->
 Btrfs needs maintenace like every filesystem. The more you use advanced features of btrfs, the more you have to watch for the right maintenance.
 === Fragmentation ===
@@ Line 214: / Line 247: @@
 When the files are only written to, or are only read seldom, '''don't worry'''.
-==== Databases ====
+==== Databases ==== <!--T:58-->
 It may be good to defragment a database if there is a ''noticeable'' slowdown when using it.
 ==== Logfiles ====
 It may be good to defragment a logfile, if there is a ''noticeable'' slowdown when booting your system.
-== Balance [https://btrfs.readthedocs.io/en/latest/Balance.html ⇒] ==
+== Balance [https://btrfs.readthedocs.io/en/latest/Balance.html ⇒] == <!--T:59-->
 When adding devices or changing the RAID-level of your volume, it may be necessary to balance your volume. While balancing, btrfs will read ALL (or a subset of all) '''chunks''' in, and write them out again using the actual RAID-level. It will stripe these files over all available devices equally. While this happens, the volume will keep being usable, but you may see some '''heavy load''' on it. Also '''this may take a very long time''' because '''ALL data must be''' read AND '''written''' again.
 Don´t worry about shutdown. When you shutdown your computer while the balance is running, the balance will pause. After you restart the computer the balance will restart and continue until it is finished.
-=== Filters ===
+=== Filters === <!--T:60-->
 Because a complete balance may take '''a long time''', there is the possibility of filters in balance. When using a filter only those chunks will be balanced, that are named by the filter.
 {{BoxDanger|Potetial Bug when using a swapfile:|  Never use a full-balance on a machine with a swapfile, since it will ignore +C Attributes. You may also have a look at [https://forum.manjaro.org/t/howto-enable-and-configure-hibernation-with-btrfs/51253/36] }}
-=== Merging chunks ===
+=== Merging chunks === <!--T:61-->
 As you use your volume, you will be creating some files, deleting some, modifying some. Then some parts of the chunks are empty. But this is not a coherent space that can be easily reused. Usually this is not a problem for btrfs and will be cleaned up automatically over time. However, if space is scarce (> 80% full), it is advisable to merge free areas together. This can be done by using balance with a filter.
-=== After removing a device ===
+=== After removing a device === <!--T:62-->
 When you remove a device from a volume, btrfs will automatically balance all "chunks" that where on the removed device. These chunks are placed on another device of the volume. So you don't need to balance by yourself after removing a device.
-=== After adding a device ===
+=== After adding a device === <!--T:63-->
 When you add a device there will be no automatic balance. Only when further using the volume, btrfs will use the additional free space according to the actual RAID-level.
-=== After changing RAID-level ===
+=== After changing RAID-level === <!--T:64-->
 When you changed RAID-levels (for example from RAID 0 to RAID 1) there is no automatic duplication of the chunks. Only when writing further, btrfs will respect the changed RAID-level. This may not be what you intended. To complete the conversion to another RAID-level you need to tell btrfs to rewrite chunks where needed. You do this with a manual balance:
+<!--T:65-->
 see: [https://btrfs.readthedocs.io/en/latest/Balance.html btrfs filesystem balance]
-== Scrub [https://btrfs.readthedocs.io/en/latest/Scrub.html ⇒] ==
+== Scrub [https://btrfs.readthedocs.io/en/latest/Scrub.html ⇒] == <!--T:66-->
 A scrub of a btrfs volume is like inspecting your home. Does the light work in every room? Is the battery of a smoke alarm empty? Does the fire extinguisher need to be replaced? Is any faucet dripping?
 Every now and then it is advisable to look for such things. And fix it right away!
-==== Check & repair on the fly ====
+==== Check & repair on the fly ==== <!--T:67-->
 Every time btrfs reads a file, it checks the corresponding checksums. When btrfs is in RAID 0 and detects a 'damaged' file, it only can tell you that the file is damaged. You may delete it, or replace it from your backup.
 When running in RAID 1 btrfs has 2 copies of every file. So if one file seems to be damaged, btrfs will read the other copy. If this other copy is ok, btrfs will automatically create another good copy of the file, and then afterwards delete the defect copy. You won't even notice this ''''automatic' repair.'''
-==== Full check ====
+==== Full check ==== <!--T:68-->
 Sometimes you may want to check ALL files, and to get a report of defects, because:
 * Some files are read very seldom, and you don't want "bitrott"
@@ Line 259: / Line 293: @@
 While checking you can enable automatic repair for RAID 1 or disable it. If you disable automatic repair, scrub will work completely readonly, and will change nothing on your volume.
+<!--T:69-->
 Scrub can be done automatically (for example every month), or manually.
+<!--T:70-->
 {{BoxInfo|Notice| Be aware, that Scrub does not structurally check the filesystem, but only checksums data and tree blocks. You may also have a look at [https://btrfs.readthedocs.io/en/latest/Tree-checker.html tree checker] }}
+<!--T:71-->
 A manual scrub is done by:
+<!--T:72-->
 {{RootCmd|command=btrfs scrub start -Bd /}}
-= Solving Problems =
+= Solving Problems = <!--T:73-->
-== Out of space ==
+== Out of space == <!--T:74-->
-==== Avoid to get out of space with btrfs! ====
+==== Avoid to get out of space with btrfs! ==== <!--T:75-->
 Don't be stingy on storage space when creating a btrfs volume. A btrfs volume should normally only be 80% full.  Then it is advisable to adjust the volume. In an emergency, 90% are okay too. But that is neither advantageous for the Btrfs volume nor for an SSD.
 {{BoxWarning|Don't forget to include the snapshots in the bill|Manjaro is a rolling release distribution. There will be a lot of changes over time.}}
@@ Line 285: / Line 323: @@
 * Do this until your disk will be not more then 95% full
+<!--T:76-->
 Do not get confused if btrfs does not immediately display the vacant space. After the next step (balance) it will become visible.
+<!--T:77-->
 * '''balance''' your volume with a filter(50%) This '''will''' take some time !
 {{RootCmd|command=btrfs balance start -musage=50 -dusage=50 /}}
@@ Line 296: / Line 336: @@
 {{RootCmd|command=btrfs balance start -musage=95 -dusage=95 /}}
+<!--T:78-->
 * '''remove the added partition''' from the volume with {{RootCmd|command=btrfs device remove /dev/[sdz4] /}}
 * This '''will''' take some time ! '''Do not reboot until this step is complete'''.
 * Now you may remove the USB-Stick.
-=== Stay out of jail ===
+=== Stay out of jail === <!--T:79-->
 * Think about how to extend the btrfs volume to '''double size'''
 * seek if there is a program filling your disk
@@ Line 306: / Line 347: @@
 * don’t forget to remove old snapshots (best done automatically)
-== Corrupted checksums ==
+== Corrupted checksums == <!--T:80-->
   [ 9364.354241] BTRFS error (device nvme0n1p3): block=58469742080 write time tree block corruption detected
 This ERROR or similar may lead to Messages like:
@@ Line 312: / Line 353: @@
 because btrfs does mount this partition '''readonly''' when it detects corrupted blocks.
+<!--T:81-->
 Now you have to investigate WHY a checksum of a btrfs block says it is corrupted.
+<!--T:82-->
 * In some cases the underlying device may beginn to fail ! => replace it (consider using RAID10)
 * In other cases a corruption may have happened even before the block had been written to disk
@@ Line 319: / Line 362: @@
 ** some software-bug ???
-== Tips ==
+== Tips == <!--T:83-->
-=== Move a volume ===
+=== Move a volume === <!--T:84-->
+<!--T:85-->
 There is an '''easy and secure way''' to move a volume to another disk/device. If you use Btrfs itself to move the volume, there will be no danger. You even can do this '''while the volume is in use'''.
 * Create the partition you want to use as ''destination'' '''without formatting''' it. Or remove the filesystem when one is present
@@ Line 338: / Line 382: @@
 {{RootCmd|command=watch -n 60 btrfs filesystem show /}}
-= Btrfs options =
+= Btrfs options = <!--T:86-->
-== Compression [https://btrfs.readthedocs.io/en/latest/Compression.html ⇒] ==
+== Compression [https://btrfs.readthedocs.io/en/latest/Compression.html ⇒] == <!--T:87-->
 Compression can only be set '''per volume'''. So if you set different "levels" of compression for different mounts in the fstab, only the first "level" will be applied. [https://btrfs.readthedocs.io/en/latest/Compression.html#how-to-enable-compression see@btrfs.readthedocs.io]
 {{BoxWarning|Grub needs to load the kernel and initrd|When you use compression on kernel, initrd, or grub config files, '''grub''' needs to decompress these files. Otherwise you will '''not be able to boot'''. GRUB introduced '''zstd''' support in '''2.04.''' Maybe you need to update grub '''and''' reinstall it}}
-== Encryption ==
+== Encryption == <!--T:88-->
 May be in the future.
-== Send + receive = backup [https://btrfs.readthedocs.io/en/latest/Send-receive.html ⇒] ==
+== Send + receive = backup [https://btrfs.readthedocs.io/en/latest/Send-receive.html ⇒] == <!--T:89-->
 Some wiki-posts in the forum:
 * [https://forum.manjaro.org/t/howto-copy-move-a-subvolume-from-one-partition-to-another/135166 move a subvolume to another volume]
 * [https://forum.manjaro.org/t/howto-use-btrfs-send-receive/135808 backup snapshots]
-== Quota groups [https://btrfs.readthedocs.io/en/latest/Qgroups.html ⇒] ==
+== Quota groups [https://btrfs.readthedocs.io/en/latest/Qgroups.html ⇒] == <!--T:90-->
 Quota support in Btrfs is implemented at the subvolume level.
+<!--T:91-->
 For more info see [https://btrfs.wiki.kernel.org/index.php/Quota_support Quota_support@btrfs.kernel.org]
 {{BoxDanger|Reports about problems|There are reports about massive problems when using quotas (especially together with snapshots, snapper, timeshift). Please have a look at: [https://btrfs.wiki.kernel.org/index.php/Quota_support#Known_issues Known_issues@btrfs.kernel.org]}}
@@ Line 362: / Line 407: @@
 * [https://forum.manjaro.org/t/files-disappearing-in-btrfs-and-ssd/28991 files-disappearing-in-btrfs-and-ssd 2020]
-== Zoned mode [https://btrfs.readthedocs.io/en/latest/Zoned-mode.html ⇒] ==
+== Zoned mode [https://btrfs.readthedocs.io/en/latest/Zoned-mode.html ⇒] == <!--T:92-->
 Beginning with version 5.12
-= Btrfs Tools =
+= Btrfs Tools = <!--T:93-->
 For complete info an all tools for btrfs please do an actual search at the arch wiki and at the manjaro forum for "btrfs". In the following section only a few commands are described. Especially those commands that are often misinterpreted. Commands described earlier are omitted.
-== btrfs (the command) [https://btrfs.readthedocs.io/en/latest/man-index.html ⇒] ==
+== btrfs (the command) [https://btrfs.readthedocs.io/en/latest/man-index.html ⇒] == <!--T:94-->
 Be aware that some sub-commands of btrfs will not work as normal user. Other sub-commands do work but will give only partial info. So best use them as ''root'' or with ''sudo''.
-==== help, version ====
+==== help, version ==== <!--T:95-->
 '''help''' together with '''man btrfs''' or '''info btrfs''' will get you an overview over the usable options on your install. {{UserCmd|command=btrfs help}}
+<!--T:96-->
 With the '''version''' of btrfs given here you can look at [https://btrfs.wiki.kernel.org/index.php/Changelog changelog].{{UserCmd|command=btrfs version}}
-==== device ====
+==== device ==== <!--T:97-->
 '''scan''' will give no visible results 😜
 {{RootCmd|command=btrfs device scan}}
+<!--T:98-->
 '''stats''' will give a list of errors detected in the past. This all should be 0, or you may be in trouble.
 {{RootCmd|command=btrfs device stats /}}
+<!--T:99-->
 What to look for in device '''usage''':
 * RAID-level of Data, Metadata and System
@@ Line 391: / Line 439: @@
-=== btrfs filesystem df / ===
+=== btrfs filesystem df / === <!--T:100-->
-=== btrfs filesystem du ===
+=== btrfs filesystem du === <!--T:101-->
 === btrfs filesystem show ===
 === btrfs filesystem usage ===
 === btrfs scrub status ===
-==btrfsck==
+==btrfsck== <!--T:102-->
 This is not what you may think it is 😜
-== Recomendations ==
+== Recomendations == <!--T:103-->
+<!--T:104-->
 {| class="wikitable"
 |+ We recommend using Btrfs with UEFI and GPT
@@ Line 415: / Line 464: @@
 |}
+<!--T:105-->
 {| class="wikitable"
 |+ IF you don't have UEFI, you may use Btrfs with BIOS and GPT
@@ Line 427: / Line 477: @@
 |}
+<!--T:106-->
 <!-- Don't forget to look more templates: https://wiki.manjaro.org/index.php/Help:Template -->
+<!--T:107-->
 <small>Please be aware that the information on this page is a simplified version of the reality. Is is written to make the reader understand a little of these complex things. To get an in depth understanding it will be neccesary to read further at btrfs.wiki.kernel.org or other places.</small>
-= Additional Information =
+= Additional Information = <!--T:108-->
 === Why not btrfs ? ===
 A lot of people say: "'''I don't use btrfs because''' it is experimental and is '''not stable'''. You can´t use it in production. It is not safe!".
-==== Not stable ? ====
+==== Not stable ? ==== <!--T:109-->
 The status of btrfs was experimental for a long time, but the core functionality is considered '''good enough for daily use'''. <small>(from kernel.org)</small>
+<!--T:110-->
 If you see statements declaring Btrfs as not stable, please look for the date of them. Some seem to date from 10 years ago. So if you want to give Btrfs a chance, you have to look for newer statements. Maybe even look at [https://btrfs.wiki.kernel.org Btrfs Kernel Wiki] as that sure is the best information regarding Btrfs
-==== Experimental ? ====
+==== Experimental ? ==== <!--T:111-->
 Btrfs is feature-rich! There are new features being implemented and these should be considered experimental for a few releases when the bugs get ironed out when number of brave users help stabilizing it.<small>(from kernel.org)</small>
+<!--T:112-->
 Some features are '''not implemented yet'''. Others are only '''partly implemented'''. Some are '''experimental''' and not suggested for production use. As is always the case in Linux-land ''you'' decide what to use, and so you are responsible for your own decisions.
-==== Not usable for production ? ====
+==== Not usable for production ? ==== <!--T:113-->
 * [https://btrfs.wiki.kernel.org/index.php/Getting_started#Distro_support Distro support] for Btrfs as main filesystem
 * Some companies do use Btrfs in production@wiki.btrfs.kernel.org
 * Some manufacturers do deploy devices where Btrfs is installed by default.
-==== Difficult to repair ? ====
+==== Difficult to repair ? ==== <!--T:114-->
 Indeed, when you search for the usual ways to repair a file system like FAT or Ext4 then you don't find good information about repairing btrfs. This is not because it is difficult to repair Btrfs, but because repairing Btrfs '''does work very differently'''.
-== What's this "Copy on Write" ==
+== What's this "Copy on Write" == <!--T:115-->
 When you want to get the most out of using Btrfs you do need to know some things about this file system. Then you are able to use it properly and to your advantage. Btrfs is not difficult, but different to some extend.
-=== Write in place (FAT32) ===
+=== Write in place (FAT32) === <!--T:116-->
 Most older file systems do write "in place". This means that some data or metadata will be written "over" the previous data at the same place.
+<!--T:117-->
 For example this is the case for FAT32 file systems. The '''F'''ile '''A'''llocation '''T'''able is at a fixed place on this file system. When the "FAT" changes (because a file got bigger and needs more blocks), this new FAT must be written with the new data to the same place as before. When the disk is ejected before (or while) this data is written, the file system will be corrupted. And the FAT does change a lot.
+<!--T:118-->
 The danger of corruption is especially big while metadata (like filename, permission, usage of disk space ...) is being written.
-=== Write to a metadata-log (Ext4) ===
+=== Write to a metadata-log (Ext4) === <!--T:119-->
 There is a solution to this with newer file systems like Ext4. Instead of writing metadata "in place", metadata is written into an "endless" log. Then it is not possible to be corrupted while overwritten. This is possible because metadata is only a very small part of the data in a file system.
+<!--T:120-->
 There has to be an additional mechanism to make this safe. Sometimes this is called "barriers", and there have to be checksums that tell when a part of the log is corrupted.
+<!--T:121-->
 This does protect the file system itself, but not the files in it. Because a file may be overwritten in place, and then the old file is lost, and the new one may not have been written completely.
-=== Copy on Write! (Btrfs)===
+=== Copy on Write! (Btrfs)=== <!--T:122-->
 Copy on Write is a "new" concept. It means the file system will try to '''never''' write over existing data. '''How is this even possible?'''
 * Files are appended at the end of a "data page"
@@ Line 481: / Line 539: @@
 * there are checksums for data and metadata
-==== Downsides ====
+==== Downsides ==== <!--T:123-->
 * Management of space is complex
 * There are 2 sorts of pages (data / metadata)
@@ Line 487: / Line 545: @@
 * It must be avoided to write data unnecessarily, because then the clean-up would also be very expensive
-==== Advantages ====
+==== Advantages ==== <!--T:124-->
 * It is possible to '''detect''' nearly any '''corruption''' because of the checksums
 * When the power is lost, or the disk is disconnected, all old data is save. WHY?
@@ Line 496: / Line 554: @@
 ** Btrfs will '''automatically roll back''' to this point, then it can mount the file system writable
+<!--T:125-->
 * CoW is a sound foundation to build upon
 ** Snapshots
@@ Line 503: / Line 562: @@
 ** Encryption (maybe some time in the future)
+<!--T:126-->
 {{BoxWarning|Don´t disable CoW in Btrfs|It is possible to disable CoW in Btrfs. But then you '''loose all benefits''' of Btrfs. It won´t even make checksums. If you don't like CoW, then you better use another filesystem}}
-= Use the Forum! =
+= Use the Forum! = <!--T:127-->
 It is a good Idea to [https://forum.manjaro.org/search?q=btrfs search the forum] for posts related to btrfs.
-= Btrfs is fast moving! See Also:=
+= Btrfs is fast moving! See Also:= <!--T:128-->
 <big>
 * [https://btrfs.readthedocs.io/en/latest/index.html btrfs.readthedocs.io]
@@ Line 514: / Line 574: @@
 </big>
+<!--T:129-->
 <!--Category or categories should have a translation extension below example-->
 </translate>
 [[Category:Boilerplate{{#translation:}}]]

Difference between revisions of "Btrfs"

Btrfs (view source)

Revision as of 08:10, 2 June 2023