rafaelweingartner commented on issue #2500: Restrict the number of managed 
clustered file systems per compute cluster
URL: https://github.com/apache/cloudstack/pull/2500#issuecomment-377227548
 
 
   @mike-tutkowski, we have discussed this in an e-mail that is not public, but 
I think it is interesting to make it public domain. Maybe @Syed can add more 
information later here as well.
   
   When I read ” XenServer 6.5 can support around 500 - 600 SRs”, it feels that 
I will have a hard limit that might be complicated to manage in some 
deployments scenarios. This means that I might not even consider the technology 
because of this said limit. However, this 500-600 number is a not a limit per 
se.  You are considering it as a limit because of the time that the XenServer 
takes to create SRs. This means, for every SR that is being created, XenServer 
is taking a little longer to create the next one. The problem is probably due 
to some poor coding around UUID checkings and validations before creating some 
metadata information; the problem seems to grow linearly (according to what I 
saw in the data presented by you and Syed in a presentation).
   
   The point is that, even though it might take 150 seconds to create the SR 
number 1000, the performance of the SR is not affected (as far as we 
discussed).  Therefore, if the admin is ok with this, he/she can use a higher 
number of SRs. That is why you externalized this configuration. However, 
without making a difference between SR performance to write and read, and the 
bottleneck in the creation of the SR, we might give the idea that it is not 
supported more than this 600 number, which is not true. The 600 number came 
after some tests execute by Syed, and to create the SR 600 it was taking 
something like 80 seconds or so, and that was considered too much for the 
context he was working on.

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
[email protected]


With regards,
Apache Git Services

Reply via email to