Déjà Dup

Bug #401094
Comment #9

Comment 9 for bug 401094

Revision history for this message

emilio (emiliomaggio) wrote on 2009-07-20: Re: [Bug 401094] Re: Slow backup speed

Also,

the 50% is not on one CPU is about 25% per CPU.

On Mon, Jul 20, 2009 at 3:32 PM, emilio maggio<email address hidden> wrote:
> It is max speed. It never goes over 300KB
>
> E.
>
> On Mon, Jul 20, 2009 at 2:54 PM, Michael
> Terry<email address hidden> wrote:
>>> Depending on how fast the network is, duplicity will be able to overlap
>>> its marshaling with the previous file being uploaded. We don't build up
>>> a queue, so if it takes longer to marshal the files for the next volume,
>>> say a bunch of small files, then you have dead time in the network.
>>
>> Right, but he said it maxes out at 300. Asynchronous shouldn't have
>> anything to do with max speed, but rather throughput. emilio, can you
>> clarify if the problem is max speed or throughput?
>>
>>> As to CPU, IO does not use much, only the marshaling process and
>>> encryption, and 50% sounds about right in bursts.
>>
>> emilio has a dual-core, so 50% is really 100% of one core. I meant that
>> since the marshaling isn't threaded, even if asynchronous were turned
>> on, we'd still only use 100% of one core. (Though we'd be using it more
>> often -- i.e. even when uploading something. Another max vs. throughput
>> issue)
>>
>> So again, unless emilo can clarify about the max/throughput question, I
>> don't think asynchronous is the answer here. We still want both network
>> and CPU maxes to be higher, even though asynchronous would help with
>> overall throughput.
>>
>> --
>> Slow backup speed
>> https://bugs.launchpad.net/bugs/401094
>> You received this bug notification because you are a direct subscriber
>> of the bug.
>>
>> Status in Déjà Dup: New
>> Status in duplicity - Bandwidth Efficient Encrypted Backup: Confirmed
>>
>> Bug description:
>> I am backing up from a laptop to an external NAS via WiFi. And I am running:
>> deja-dup 10.1-0jaunty1
>> duplicity 0.6.02-0jaunty1
>>
>> I have tested the file writing speed of the NAS and it is of about 2MB/s. However when backing up with deja-dup the speed tops at about 300KB/s.
>>
>> Interesting is also the fact that the backup on my dual core machine uses only 50% of the available computational power spread over the two cores.
>>
>> Any idea on where the bottleneck might be?
>>
>

Also,

the 50% is not on one CPU is about 25% per CPU.

On Mon, Jul 20, 2009 at 3:32 PM, emilio maggio<emiliomag@googlemail.com> wrote:
> It is max speed. It never goes over 300KB
>
> E.
>
> On Mon, Jul 20, 2009 at 2:54 PM, Michael
> Terry<michael.terry@canonical.com> wrote:
>>> Depending on how fast the network is, duplicity will be able to overlap
>>> its marshaling with the previous file being uploaded. We don't build up
>>> a queue, so if it takes longer to marshal the files for the next volume,
>>> say a bunch of small files, then you have dead time in the network.
>>
>> Right, but he said it maxes out at 300.  Asynchronous shouldn't have
>> anything to do with max speed, but rather throughput.  emilio, can you
>> clarify if the problem is max speed or throughput?
>>
>>> As to CPU, IO does not use much, only the marshaling process and
>>> encryption, and 50% sounds about right in bursts.
>>
>> emilio has a dual-core, so 50% is really 100% of one core.  I meant that
>> since the marshaling isn't threaded, even if asynchronous were turned
>> on, we'd still only use 100% of one core.  (Though we'd be using it more
>> often -- i.e. even when uploading something.  Another max vs. throughput
>> issue)
>>
>> So again, unless emilo can clarify about the max/throughput question, I
>> don't think asynchronous is the answer here.  We still want both network
>> and CPU maxes to be higher, even though asynchronous would help with
>> overall throughput.
>>
>> --
>> Slow backup speed
>> https://bugs.launchpad.net/bugs/401094
>> You received this bug notification because you are a direct subscriber
>> of the bug.
>>
>> Status in Déjà Dup: New
>> Status in duplicity - Bandwidth Efficient Encrypted Backup: Confirmed
>>
>> Bug description:
>> I am backing up from a laptop to an external NAS via WiFi. And I am running:
>> deja-dup        10.1-0jaunty1
>> duplicity       0.6.02-0jaunty1
>>
>> I have tested the file writing speed of the NAS and it is of about 2MB/s. However when backing up with deja-dup the speed tops at about 300KB/s.
>>
>> Interesting is also the fact that the backup on my dual core machine uses only 50% of the available computational power spread over the two cores.
>>
>> Any idea on where the bottleneck might be?
>>
>