Citrix XenServer Health Check and Best Practices

These notes were compiled prior to a Health Check engagement on a multi-node XenServer environment with a view to planning and then undertaking the upgrade to XenServer 6.0.2 (which is the latest stable version.)

Note: XenServer 6.1 is the current latest version of XenServer, alas there are some issues with the XenServer 6.1 version of the XenServer Tools which is why Citrix are currently recommending –

“We advise customers to remain on XenServer 6.0.2 (or earlier) until Citrix releases a hotfix to XenServer 6.1 that addresses the known issues in the XenServer Tools. This will prevent you needing to upgrade the Tools in your VMs twice (once for base XenServer 6.1, and again when the hotfix is released).” – Source XenServer Tools Workarounds for XenServer 6.1.0 (CTX135099) (Update Dec 21, 2012)

Hotfix XS61E005 is due in early January 2013 to fix this (http://blogs.citrix.com/2012/12/18/xenserver-xentools)

Questions

Citrix AutoSupport (XenServer 5.6 and above)

- Can we extract AutoSupport information?

How to Collect Diagnostic Information for XenServer (CTX125372)

Host Server

- What make are model are the hosts servers?

- What specification (RAM, CPU, local disk, number of NICs)?

- What version(s) of XenServer are in use, and Hotfixes installed?

- Are the hosts pooled or standalone?

- What guests are running on the hosts?

- Does the current pool utilization allow one host to be taken offline for purposes of upgrade?

- Is the environment being used for VDI?

- Is the environment being used with Citrix Provisioning Services?

- How is the environment being backed up?

- How is the environment monitored?

- Power cabling (Best practice - dual power feeds from separate circuits)?
- Where are the host servers (and - if in a datacenter - do we have remote access via iDRAC/ iLO/ etc.)?

Note on versions:

The Citrix XenServer Dell Edition exists only from 5.0 to 5.6!

Host Server Networking

- How many NICs and in use and for what purpose?

Example (Best Practice Minimum):

2 for XenServer Management and XenMotion Traffic

2 for Virtual Machine Traffic

2 for iSCSI Storage Traffic

Figure: XenServer Networking

- Are NICs bonded (best practice including for iSCSI)?

- Distributed Virtual Switch (DVS) in use?

- Are separate physical switches being used for iSCSI?

- Jumbo Frames, Flow Control, Unicast Storm Control disabled, VLAN Segmentation, PortFast, Hard-coded Duplex and Port Speed settings, etc. (specifically for iSCSI)?

Licensing

- How are the current XenServer hosts licensed, and what edition (Free XenServer licensing or via a license server)?

- What version is the current license server, and where is this installed (Installed on Windows guest or licensing appliance – latest VPX 11.1)?

- Is licensing available for an upgrade?

Storage

- What storage arrays are in use?

- How many storage arrays?

- What firmware/software version are the arrays on?

- What type of Storage Repositories are used (local EXT3, local LVM, NFS, Hardware HBA, Software iSCSI, Citrix StorageLink)?

- If using NetApp/EqualLogic, is the Advanced Citrix StorageLink type SR in use?

- Any report issues for SAN/Storage (e.g. latency issues)?

- Can we have SAN diagnostic outputs?

- If NetApp, can we have a full AutoSupport output?

- If EqualLogic, can we have a full SAN HQ output?

Figure: Dell EqualLogic SAN HeadQuarters – Export All Group Data

Note 1: There are no specific EqualLogic Host Integration Tools for XenServer.
Note 2: See http://cosonok.blogspot.com/2012/11/installing-and-using-netapp-virtual.html for the NetApp VSC for XenServer 6

Miscellaneous

- Are the any issues with the current environment?

Further Reading

XenServer – Resources and Support

http://www.citrix.com/products/xenserver/resources-and-support.html

XenServer Proddocs – Versions 5.0 to 6.1.0

http://support.citrix.com/proddocs/topic/xenserver/xs-where-are-docs-wr.html

XenServer 6.0.2

XenServer 6.1.0

Citrix Software for Dell PowerEdge Servers

http://support.euro.dell.com/support/edocs/software/Citrix/index.htm

Citrix XenServer 5.6 Feature Pack 1 Solutions Guide