[pve-devel] Speed up PVE Backup

[Stefan Priebe - Profihost AG]

Am 16.02.2016 um 11:02 schrieb Martin Waschbüsch:
> 
>> Am 16.02.2016 um 10:32 schrieb Stefan Priebe - Profihost AG <s.priebe at profihost.ag>:
>>
>> Am 16.02.2016 um 09:57 schrieb Martin Waschbüsch:
>>> Hi Stefan,
>>
>>>> This is PVE 3.4 running Qemu 2.4
>>>
>>> To me this looks like the compression is the limiting factor? What speed do you get for this NFS mount when just copying an existing file?
>>
>> Which compression? There is only FS compression on the target side
>> involed. I'm not using any compression on the source side.
> 
> Sorry, reading the 26MB/s I just assumed it sort of HAD to be compressed for it to be so slow...
> What kind of storage backend do you use for the images on the source side?

Storage Backend is ceph using 2x 10Gbit/s and i'm able to read from it
with 500-1500MB/s. See below for an example.

> Can you dd a disk image from that backend to the nfs mount with good speed?

Yes.

# time rbd -p cephstor4 export vm-264-disk-1 abc.img
Exporting image: 100% complete...done.

real    1m30.828s
user    1m3.858s
sys     0m43.645s

# du -h abc.img
30G     abc.img

Stefan