Tags » Libguestfs

Libguestfs appliance boot in under 600ms

$ ./run ./utils/boot-benchmark/boot-benchmark
Warming up the libguestfs cache ...
Running the tests ...

test version: libguestfs 1.33.28
 test passes: 10
host version: Linux moo.home.annexia.org 4.4.4-301.fc23.x86_64 #1 SMP Fri Mar 4 17:42:42 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
    host CPU: Intel(R) Core(TM) i7-5600U CPU @ 2.60GHz
     backend: direct               
        qemu: /home/rjones/d/qemu/x86_64-softmmu/qemu-system-x86_64 
qemu version: QEMU emulator version 2.5.94, Copyright (c) 2003-2008 Fabrice Bellard
         smp: 1                    
     memsize: 500                  

Result: 575.9ms ±5.3ms
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Using libguestfs to mount a Disk Image.

Recently, the opensource community and Red Hat are not supporting NTFS filesystem to mount images using libguestfs. You can read the official documentation accessing the specific section: … 267 more words


libguestfs appliance boot in under 1s

$ time LIBGUESTFS_BACKEND=direct LIBGUESTFS_HV=~/d/qemu/x86_64-softmmu/qemu-system-x86_64 guestfish -a /dev/null run

real	0m0.966s
user	0m0.623s
sys	0m0.281s

However I had to patch qemu to enable DMA loading of the kernel and initrd.

Getting the libguestfs appliance boot time down to 1.2s

libguestfs can securely mount any disk image, but to do this it requires a small appliance to be run. The appliance is a very cut down Linux distro, but it still takes time to boot. 7,672 more words

Tracing QEMU guest execution part 4

The final two questions that I posed last time were to do with constructing a timeline of what this guest is spending time on.

We can easily see system calls in the trace log, and we can also see when a kernel function is entered the first time (indicating that a new bit of the kernel is now running), and I wrote a Perl script to analyze that. 143 more words

Tracing QEMU guest execution part 3

In the previous post I posed three questions about my detailed function-level trace of the kernel booting under QEMU. The first one was Which kernel functions consume the most time? 790 more words