Increasing hosts connection pool
Johnny Zhang
Note: This is tip is based on communications between engineering and myself. In most cases there is no need to make any change. This is just for you to know. (This also only based on VI3, not sure if there are changes on vSphere)

Sometimes we see ESX hosts disconnected from vCenter. from the vpxa log files:

['App' 7644 error] [VpxdVmomi] Got vmacore exception: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

This error is common in an environment which hosts are under load.
There could be multiple causes for this kind of connection request failure:

1. Network glitch
2. proxy server on hostd is not able to respond the request due to stress.
3. hostd process is busy or crashed at the time the request arrives.

Now, vCenter has a host connection pool, it will store idle connections between ESX server and vCenter. So when there is a need to connect the server, vCenter will not need to create the connections all over again (Which in some cases we will hit the above issues). The default connection size is set at 20. you can increase this (for example to 50)

You need to add to vpxd.cfg files:

Personally, I believe this will help for a large set-up by reducing the connection requests. please note, the active connection is not put into this pool, so in most cases 20 is good enough.
Labels: 0 comments | edit post
Two fast ways to locate your console root on ESX 4.x
Johnny Zhang
vShpere change the way to store the console OS. It's now running on a VMDK file. It's a real virtual machine. There are times you may want to know where is your root VMDK file for your console OS. Here is two fast ways to locate it.

1. From /proc/vmware: "rootFsVMDKPath" under /proc/vmware will give you the location of your root VMDK

2. Use of "vsd" command: You can use "vsd -g" to list your root VMDK file.
Labels: 0 comments | edit post
How to clean event from vCenter database
Johnny Zhang
Please keep in mind, clean up event is not recommended, do it ONLY when you are running out of space because both vpx_event_arg and vpx_event tables are filled with many GB of data.
Always shut down vCenter service before you do anything with the database.
You can check the space usage by each table:

********************************************
use "name_of_the_vcdb"
CREATE TABLE #TemptableforspaceUsed
(name SYSNAME,
rows bigINT,
reserved VARCHAR(20),
data VARCHAR(20),
index_size VARCHAR(20),
unused VARCHAR(20))
GO
INSERT #TemptableforspaceUsed
EXEC sp_MSforeachtable 'sp_spaceused "?"'

select *
from #TemptableforspaceUsed

drop table #TemptableforspaceUsed

******************************************

You can now clean the event tables.

use "name_of_the_vcdb"
truncate table vpx_event_arg;
delete from vpx_event;

Because there are foreign keys inside vpx_event, you can not truncate the data inside. You must remove those data before start the vCenter service, the service might not start if there are data that is missing link. Please also keep in mind, "delete" will always save a copy of the change, so you will see increase in transaction logs, sometimes it can be huge, depends on the amount of data you have.
Labels: 1 comments | edit post