[ILUG] Subversion speed question

[Niall O Broin]

On 31 Jul 2006, at 20:31, kevin lyda wrote:

> On Mon, Jul 31, 2006 at 07:25:10PM +0100, Niall O Broin wrote:
>> We have a repository on a Linux server which has about 1000 files,
>> and an export uses about 13M of space. Running svn export svn://
>> server/repo/trunk takes these times:
>>
>> Client			Time		Subversion version
>> 	
>> Server - SuSE 9.3	4s		1.3.0
>> SuSE 9.3		2m27s		1.3.0
>> Ubuntu dapper		2m20s		1.3.1
>> OS-X PPC		13s		1.3.2
>> OS-X Intel		17s		1.3.2
>>
>>
>> Most of the clients are connecting over GiGE, except for the OS-X PPC
>> box, which is using 802.11g. The GiGE network is OK - a quick and
>> dirty check on the SUSE 9.3 box copied files from an NFS mounted
>> volume of the subversion server to local at > 15MB/sec .
>
> how would a disk speed benchmark compare?  what about network  
> performance?

Those two questions together put me on the right track. The cause of  
the problem was that on both of the Linux boxes I was checking out to  
an NFS mounted home directory. Bit of a Doh! issue really, as I have  
been putting up with NFS slowness for rather a long time now. Raw  
write speed isn't too bad (37s to write a 335M file as against 22s to  
write to a local disk, the source of the file being another NFS  
mount) but NFS file operations are expensive. I did a little test  
like this:

time (for in in `seq 1 1000`;do cp /etc/passwd nfstest/file$x;done)

With nfstest on an NFS mount, this took 1m32s. With nfstest on a  
local disk it took 14s.

Running the NFS checkout on Linux to a local disk takes 13s.

The moral of the story is that Linux as an NFS server sucks, but  
that's hardly news.


Niall