Reintroduce support for lzop compression

lzop was removed due to some confusion over whether it provided functional
advantages distinct from xz. This has been addressed in the mailing list post
archived at http://permalink.gmane.org/gmane.comp.emulators.libvirt/16487, and
support for lzop is re-added here.

* libvirt.spec.in: add dependancy on lzop
* src/qemu.conf: update documentation of save_image_format
* src/qemu_driver.c: re-add lzop compression option

diff --git a/libvirt.spec.in b/libvirt.spec.in
index b01f9c2e9ab1c49585d09dfc670064cd5c2283b7..0157eeea67f31f7ef9fce69a19bc6c86c8b9d189 100644 (file)
--- a/libvirt.spec.in
+++ b/libvirt.spec.in
@@ -117,6 +117,7 @@ Requires: /usr/bin/qemu-img
 # For image compression
 Requires: gzip
 Requires: bzip2
+Requires: lzop
 Requires: xz
 %else
 %if %{with_xen}

diff --git a/src/qemu.conf b/src/qemu.conf
index 342bb8a19c2e325d636f28fbfe172eb41af042ba..6d6b86afdb65bfd2741333e840c218734b359377 100644 (file)
--- a/src/qemu.conf
+++ b/src/qemu.conf
@@ -134,9 +134,10 @@
 # memory from the domain is dumped out directly to a file.  If you have
 # guests with a large amount of memory, however, this can take up quite
 # a bit of space.  If you would like to compress the images while they
-# are being saved to disk, you can also set "gzip", "bzip2", "lzma", "xz",
-# or "lzop" for save_image_format.  Note that this means you slow down
-# the process of saving a domain in order to save disk space.
+# are being saved to disk, you can also set "lzop", "gzip", "bzip2", or "xz"
+# for save_image_format.  Note that this means you slow down the process of
+# saving a domain in order to save disk space; the list above is in descending
+# order by performance and ascending order by compression ratio.
 #
 # save_image_format = "raw"
 

diff --git a/src/qemu_driver.c b/src/qemu_driver.c
index 8f16e726cb61d0da4123b2d0ada3c66dca97d152..5c2a8ec255d4c11d89a055789c5ff6ad8daaab19 100644 (file)
--- a/src/qemu_driver.c
+++ b/src/qemu_driver.c
@@ -3624,10 +3624,10 @@ enum qemud_save_formats {
     QEMUD_SAVE_FORMAT_BZIP2 = 2,
     /*
      * Deprecated by xz and never used as part of a release
-     * QEMUD_SAVE_FORMAT_LZMA,
-     * QEMUD_SAVE_FORMAT_LZOP,
+     * QEMUD_SAVE_FORMAT_LZMA
      */
     QEMUD_SAVE_FORMAT_XZ = 3,
+    QEMUD_SAVE_FORMAT_LZOP = 4,
     /* Note: add new members only at the end.
        These values are used in the on-disk format.
        Do not change or re-use numbers. */
@@ -3640,7 +3640,8 @@ VIR_ENUM_IMPL(qemudSaveCompression, QEMUD_SAVE_FORMAT_LAST,
               "raw",
               "gzip",
               "bzip2",
-              "xz")
+              "xz",
+              "lzop")
 
 struct qemud_save_header {
     char magic[sizeof(QEMUD_SAVE_MAGIC)-1];
@@ -4384,6 +4385,8 @@ static int qemudDomainRestore(virConnectPtr conn,
             intermediate_argv[0] = "bzip2";
         else if (header.compressed == QEMUD_SAVE_FORMAT_XZ)
             intermediate_argv[0] = "xz";
+        else if (header.compressed == QEMUD_SAVE_FORMAT_LZOP)
+            intermediate_argv[0] = "lzop";
         else if (header.compressed != QEMUD_SAVE_FORMAT_RAW) {
             qemudReportError(conn, NULL, NULL, VIR_ERR_OPERATION_FAILED,
                              _("Unknown compressed save format %d"),