64TB VMDKs? Yes we can.

Here’s a tasty tidbit for you – in the just announced vSphere 5.5, we can now create 64TB VMDK files.  While much of vSphere 5.5 offers a 2x increase in configuration maximums over vSphere 5.1, the increase in VMDK size is a whopping 32x.  (It may actually be a bit less – I’m not sure if the -512B caveat comes into play on the virtual disk size for vSphere 5.5.  I didn’t think to test this out in the lab during my beta testing… the max size is actually 62.9TB as space is reserved in the containing VMFS for snapshots, metadata, etc.). Now just because you can, doesn’t mean you should.  I … [Read more...]

Is Spanning VMDKs Using Windows Dynamic Disks a Good Idea?

I've had several folks ask me recently about how to support very large NTFS volumes on vSphere virtualized Windows servers.  The current limitation for a VMDK in vSphere 5.1 is 2TB minus 512B.  FWIW, a Hyper-V virtual disk in Windows Server 2012 can be up to 64TB.  Those asking the question want to support NTFS volumes greater than 2TB for a variety of purposes - Exchange databases, SQL databases, and file shares.  Windows (depending on the version and edition) can theoretically support NTFS volumes up to 256TB (depending on cluster size and assuming GPT), with files up to 256TB in size (see … [Read more...]

Cleanup Archived Event Logs with PowerShell

I ran into an environment today where a group policy object (GPO) was configured at the domain level that set security logs to be archived to the C: drive when full.  The need for the policy abated, then the policy was removed.  But, the setting to archive event logs on each server and workstation in the domain persisted.  Hard drives - physical and virtual - began to fill up, taking down critical services.  The fix was easy, but I thought I would share for others who might run into the same issue. First, I set a group policy to configure appropriately sized logs and retention policies on … [Read more...]

Storage Basics – Part VII: Storage Alignment

At the risk of beating a dead horse, it's time to resurrect my Storage Basics series.  I've recently had some great feedback on the series and figured I should round out a few of the concepts before I wrap it up.  I want to cover a topic often discussed amongst virtualization professionals, but one I often find general practitioners and server admins not understanding: storage alignment.  Storage alignment, or the lack of alignment, is not a new issue and is not unique to VMware or virtualization in general.  However, the effects of misaligned storage can be more greatly felt in terms of … [Read more...]