Re: [libvirt] Re: [PATCH] also allow use of XZ for Qemu image compression
Jim Meyering wrote:
Good point about it being one of the fastest.
I shouldn't have mentioned the subjective "popular".
Usefulness trumps that. I suppose Daniel, Cc'd, will decide.
Per off-list discussion with DV, I'm providing some numbers. Sort order
is space used on disk, lowest to highest, with a 251MB file created by
virDomainSave.
comptime[*] decomptime[*] space
xz[default] 3m45.890s 4.960s 42MB
xz[0] 0m17.450s 6.080s 54MB
bzip2 0m56.290s 11.080s 58MB
gzip 0m13.790s 2.260s 64MB
lzop 0m1.970s 0.800s 87MB
I believe this makes the distinct niche of each of the compressors
clear, with the exclusion of bzip2 (which is both slower and produces
larger output compared to xz -0).
[*] "time" is user-mode CPU time, as reported by the bash "time"
builtin
on an Intel Xeon E7330 @ 2.40GHz.