Differences between revisions 1 and 5 (spanning 4 versions)

BTRFS filesystem

reflinks
- cp --reflink name1 name4
- reflinks are supported by BTRFS and OCFS2 and support transparent copy on write which is especially useful for snapshotting.
- Note that since separate inodes are used, one can have different permissions to access the same data.
- Reflinks have the same use as hardlinks, but are more space efficient and generally handle all subsequent operations on a file, not just unlink().
If you have virtual images on a btrfs, cow(copy on write) will cause a lot of fragmentation, turn it of for the directory of file with
- this disables cow(fragmentation) and also crc calculations on the files.
  - ```
       chatter +C /path
```

defrag with

   btrfs filesystem defragment /path/file

or faster for large files

     cp --reflink=never vbox.vdi vbox.new.vdi ; rm vbox.vdi ;

Create raid array, raid1 all data mirrored once.
- # mkfs.btrfs -m raid1 -d raid1 -L root /dev/disk/by-label/root1 /dev/disk/by-label/root2 /dev/disk/by-lab

el/root3 /dev/disk/by-label/root4

HP Server Raid tools

...

-  ⇤ ← Revision 1 as of 2011-11-01 11:59:16 → 
  Size: 413
  Editor: PieterSmit
  Comment:
+   ← Revision 5 as of 2015-07-02 18:59:49 → ⇥
  Size: 1429
  Editor: PieterSmit
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 6:
+ * reflinks
   {{{ cp --reflink name1 name4 }}}
   * reflinks are supported by BTRFS and OCFS2 and support transparent copy on write which is especially useful for snapshotting. 
   * Note that since separate inodes are used, one can have different permissions to access the same data. 
   * Reflinks have the same use as hardlinks, but are more space efficient and generally handle all subsequent operations on a file, not just unlink().
 * If you have virtual images on a btrfs, cow(copy on write) will cause a lot of fragmentation, turn it of for the directory of file with
   * this disables cow(fragmentation) and also crc calculations on the files.
     {{{
     chatter +C /path
     }}}
    
 * defrag with
   * {{{
   btrfs filesystem defragment /path/file
   }}}
   * or faster for large files
     {{{
     cp --reflink=never vbox.vdi vbox.new.vdi ; rm vbox.vdi ;      }}}
-Line 14:
+Line 31:
-   * mount optione subvol=homevol
+   * mount option subvol=homevol

== HP Server Raid tools ==
 * http://dmatwork.blogspot.com/2010/07/installation-of-hp-array-configuration.html