| Message ID | 1498733831-15254-5-git-send-email-pl@kamp.de |
|---|---|
| State | New |
| Headers | show |
Am 29.06.2017 um 12:57 hat Peter Lieven geschrieben: > Signed-off-by: Peter Lieven <pl@kamp.de> > --- > qemu-img.texi | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/qemu-img.texi b/qemu-img.texi > index 5b925ec..430f0b9 100644 > --- a/qemu-img.texi > +++ b/qemu-img.texi > @@ -621,6 +621,27 @@ file which is COW and has data blocks already, it couldn't be changed to NOCOW > by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if > the NOCOW flag is set or not (Capital 'C' is NOCOW flag). > > +@item compress.format > +Defines which compression algorithm is should be used for compressed clusters. > +The following options are available if support for the respective libraries > +has been enabled at compile time: > + > + zlib Uses standard zlib compression > + > +The compression algorithm can only be defined at image create time and cannot > +be changed later. > + > +Note: defining a compression format will result in the compression format > + extension being written to the Qcow2 image. Older versions of QEMU will > + not be able to open images with this extension. Why not more specifically "QEMU versions before 2.10"? > +@item compress.level > +Defines which compression level is used for the selected compression format. > +The default of @code{compress.level=0} will use the default compression level > +for the format. Alternate values range from 1 for fastest compression to > +x for the best compression (x max vary between compression formats). This is > +always a trade in of compression speed against compressed size. Start with something like "valid for compress.format=zlib" and then give the exact range of valid values for zlib. Kevin
diff --git a/qemu-img.texi b/qemu-img.texi index 5b925ec..430f0b9 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -621,6 +621,27 @@ file which is COW and has data blocks already, it couldn't be changed to NOCOW by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if the NOCOW flag is set or not (Capital 'C' is NOCOW flag). +@item compress.format +Defines which compression algorithm is should be used for compressed clusters. +The following options are available if support for the respective libraries +has been enabled at compile time: + + zlib Uses standard zlib compression + +The compression algorithm can only be defined at image create time and cannot +be changed later. + +Note: defining a compression format will result in the compression format + extension being written to the Qcow2 image. Older versions of QEMU will + not be able to open images with this extension. + +@item compress.level +Defines which compression level is used for the selected compression format. +The default of @code{compress.level=0} will use the default compression level +for the format. Alternate values range from 1 for fastest compression to +x for the best compression (x max vary between compression formats). This is +always a trade in of compression speed against compressed size. + @end table @item Other
Signed-off-by: Peter Lieven <pl@kamp.de> --- qemu-img.texi | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)