Tuesday, November 29, 2011

Citrix Xenapp Best Practices

A while ago I talked about Citrix Xenapp on VMWare, but now I came across best practices, both from VMWare as well as Citrix. So without further ado:



Both of them say about the same I said in my first post, with some more details.

Friday, November 25, 2011

Invalid configuration for device ’0′ when enabling a NIC in vSphere

Suddenly a VM was unreachable on all interfaces. Upon investigation, I saw that none of the NIC's were set to connected:

When I tried to enable them again I got Invalid configuration for device ’0′:

Some googling led to a simple solution, which is to restart the management agents:

service mgmt-vmware restart


service vmware-vpxa restart

Good to know. Thanks go to the cupfighters for investigating it deeper and leading me to the answer.

Tuesday, November 22, 2011

Disable Symantec AV via scripting

A small script to quickly disable Symantec Antivirus 11 (Symantec Endpoint Protection) for those moments that it needs to be disabled quickly:

Open up an administrative commandprompt and type the following commands:

sc config "Symantec AntiVirus" start= disabled
sc config ccEvtMgr start= disabled
sc config SmcService start= disabled

net stop "Symantec AntiVirus"
net stop ccEvtMgr

taskkill /IM smc.exe /F

Symantec Antivirus is now completely disabled

Thursday, November 17, 2011

NFS advanced settings for ESX/ESXi

Netapp has this wonderful Best Practices document available online, which is well worth the read. It used to include the CLI commands but this has been transferred to a new document.

As part of the best practices of an ESX/ESXi installation , you need to change some settings for NFS. I keep forgetting which ones they are, so this a reminder to myself (and anyone that reads this blog ;-) )

The easiest thing to do, is to start up the Remote Tech Support (SSH) service in the security profile, SSH to the host, and copy/paste this into the SSH window:

/usr/sbin/esxcfg-advcfg -s 30 /Net/TcpipHeapSize 
/usr/sbin/esxcfg-advcfg -s 120 /Net/TcpipHeapMax 
/usr/sbin/esxcfg-advcfg -s 10 /NFS/HeartbeatMaxFailures 
/usr/sbin/esxcfg-advcfg -s 12 /NFS/HeartbeatFrequency 
/usr/sbin/esxcfg-advcfg -s 5 /NFS/HeartbeatTimeout 
/usr/sbin/esxcfg-advcfg -s 64 /NFS/MaxVolumes

Note that the last setting says MaxVolumes: 64. The default is set to 8, which means that the maximum number of NFS volumes is 8 by default. Setting the maximum to 64 works for ESX 4.x, but used to be 32 for ESX 3.x. ESX 5.x can even go to 128.

 If you want to follow what VMWare says instead of the Netapp Best Practices, you can set the TCPIP Heap Size to 32 in ESX4/5(see here).

Update for 5.1:

/usr/sbin/esxcfg-advcfg -s 32 /Net/TcpipHeapSize
/usr/sbin/esxcfg-advcfg -s 128 /Net/TcpipHeapMax
/usr/sbin/esxcfg-advcfg -s 10 /NFS/HeartbeatMaxFailures
/usr/sbin/esxcfg-advcfg -s 12 /NFS/HeartbeatFrequency
/usr/sbin/esxcfg-advcfg -s 5 /NFS/HeartbeatTimeout
/usr/sbin/esxcfg-advcfg -s 256 /NFS/MaxVolumes