Archive for November, 2009

Sophos – Jumping through hoops !

Testing the new version of Sophos in a lab environment leads me to some interesting facts;

Enterprise console – the management back office of “Sophos Endpoint Security and Data Protection” does not currently support Windows Server 2008 R2 (release 2 available from October)

Remote deployment doesn’t work on Windows Vista or Windows 7 unless you take a variety of steps including running the remote registry service (+ setting to automatic start), modifying the local security policy disabling UAC for admins, opening various ports or just disabling the windows firewall in frustration, enabling file and printer sharing. Remote deploy on fully updated XP machines can also be problematic.

The client firewall doesn’t support servers (obviously) or 64 bit workstations (you what?) - including the 64 bit variants of XP, Vista and Windows 7! Though you’ll be pleased to know that 64 machines are supported if they run a 32 bit OS.

Come on Sophos adapt ! This isn’t 2003 anymore!

VMware VMFS Volume Size – Finding the Sweetspot

Reading a knowledge base post on the equallogics site I gleaned the following variables in relation to ESX that will have a factor on deciding VMFS volume size;

  1. ESX has a limit of 64 targets (volumes) per host
    • This is important in a HA / DRS environment where each host in the cluster must have access to all volumes even if the guest is currently running on another host.
    • Hence keeping volume counts down will improve scalability of the cluster
  2. ESX has a maximum queue length per target of 32 IO’s -
    • Thus more volumes means less pausing of IO opperations
  3. Certain Opperations (Start/Stop VM / Snapshot / vMotion) Require exclusive access to volume
    • Thus for a short period of time other vm’s IO is paused -
    • the more VM’s per volume the more this will impact performance
  4. VI 3.5 didn’t support MPIO so more volumes increased throughput
    • Does this matter anymore with MPIO in ESX 4? and multiple sessions per host taking advantage of all paths to the target.
  5. Don’t forget to account for snapshots in your volume size
    • vmware snapshots grow very quickly as they are an on-write copy delta of both the vm memory and it’s virtual hard disk.
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