Q: Increasing samba lock performance in a ctdb 1.2 setup?

[Rainer Krienke]

Am 09.11.2012 13:37, schrieb Amitay Isaacs:
Hello Amitay,
...
>> The fake oplocks for the software share helped already a lot making
>> firefox on windows start up faster (max about 1 minute) which is far
>> better that 5 minutes or more.
> 
> How is firefox configured on windows clients? Is it using share name
> "software" to share the installation of firefox among windows clients?

I am not sure if I understand exactly what you mean. The software share
contains the complete firefox installation, so there is no local
installation on each windows client except for the menu entry. The user
specific files are found on the users profile share which is also served
by the ctdb cluster.

> 
>> I now wonder what I could do else to increFunk-Heizkörperthermostat Premium Model Gase performance for windows
>> locking which seems to be the bottle neck to me.  I found information
>> that suggests to use a ramdisk to store some ctdb databases that are now
>> stored in /var/lib/ctdb on a local (virtual) disk on each cluster node.
>>
>> Can anyone tell me *which tdb files* exactly I should place on the
>> ramdisk? Is it ok to place a symlink in /var/lib/ctdb/<linkname> to the
>> file in the ramdisk or how else should I do this?
> 
> It might be premature to use tdb files from ramdisk without figuring
> out what's causing the lock contention.

Do you have an idea how to find out more? For me this looks like as if
windows simply does a lot of locking which causes a very high load on
ctdb if many users are active especially if many of the users start a
specific software like firefox located on the cluster.

Before we used the ctdb based cluster (only since a week now) we relied
on two physical 7 years old linux SLES servers running samba without
clustering, but offering the same shares to the same number of users.
Using these servers we did not have the peformance problem.

So whats different now is 1. we are using ctdb and 2. that the servers
are running as virtual machines now instead of beeing physical servers.
 So my guess is that the combination of ctdb requiring fast local disks
and the fact that ctdb is running on a virtual machine with virtual and
thus slower disks might be problematic.

Thats why I asked about putting some ctdb databases on a fast ramdisk.

Have a nice day
Rainer