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Ploop/sparse

497 bytes added, 21:45, 16 December 2013
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While ploop is never creating sparse image files, they can be accidentally made so when tools such as <code>rsync --sparse</code> or <code>cp --sparse=always</code> are used to copy images. So, one should not use backup or copy tools that create sparse files out of non-sparse ones.
 
== Kernel warning ==
 
In case sparse file is detected by the kernel, it gives a warning in dmesg, for example:
 
Nov 21 20:37:27 sun kernel: [43451.057489] ploop(24002): a hole in image file detected (0)
 
In case there are no other ploop-related warnings or errors immediately after, this one is harmless ({{B|2825}}).
 
== How to fix ==
Since [[Download/ploop/1.10|ploop-1.10]], ploop images are checked for being sparse and are automatically fixed on mount, in case DiskDescriptor.xml is used. Otherwise, you can use <code>ploop check --repair-sparse</code> to check for and repair such images.
 
Alternatelely, you can just do something like this to get rid of holes. Make sure ploop file is not used!
 
cat root.hdd > root.hdd2 && mv root.hdd2 root.hdd
== See also ==