Low Disk Space Server 2008 R2

GalaxyTechService used Ask the Experts™
Hello Experts,

We have a Windows Server 2008 R2 running Hyper-V with one VM.  The VHD for the VM is fixed and does not change size, But for some reason we keep rinning low on disk space for the host causing the VM to go into a paused state almost daily.  I find what ever files, downloads, ect... that are not needed to clear up some space to buy us time.  Any idea what could be causing a increse of about 100mb a day to the point we are running out of space on out C: drive?

Thank you,

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AlexSenior Infrastructure Analyst


DIsk cleanup to start, then treesize, then increase the disk space.


I'm with Alex Green but, for clarification, what is the function of the server itself (i.e. role, service, etcetera)?
Distinguished Expert 2017

Do you have the option to move the hyper-v guests vhds away from the C: drive?
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@N8ivelT, it runs our Hyper-V

@arnold, no it's the only sever we have in the office at this moment.
Distinguished Expert 2017

do you have expansion drive slots available in the server? Is the server hot-swap for drive? Most of those can add drives, configure them and function while the system is running?

The other option is to ask what other services/functions/roles does this single server have in addition to hyper-v (it does not sound as though you are running hyper-v core....?
file share?
anti-virus/security/end point application that retrieves updates ....
I think leew had written an article on c:\ drive cleanup

for wsus running the cleanup might release some space.
file share, unless you have an option...
exchange, unless you have archiving/expiration policy the space consume will continue to grow.

with what you have currently, your options are limited.

server hardware spec?
Vendor, make model, ...
It may be the host but some businesses make their host the DC / AV server / etcetera ... that's why I'm asking specifics.

Personally, I would not create VHDs on an OS drive for the very issue you are having. If the server is mission critical, then I would either add disks and move the VHD(s) to them or upgrade to newer hardware (with redundancy and increased disk space options). If these options are too expensive (i.e. deemed "too expensive" by management), then they need to determine what downtime costs (vs good disk space, redundancy and backup) and then reassess their conclusion.

This may sound strong but being able to run a business usually is more profitable than the alternative.

If you are a technical consulting company and they cannot see the value of this, then it may be the beginning of a thorny relationship ... if it is your server, then, as my old boss used to say, "The cobbler's son has no shoes." :)
Alex Green has it.  95% chance when you run Treesize the WinSXS folder will be very large.  This is where all of the older Windows updates are cached.  You should be able to reduce the size by running cleanmgr, clicking Windows update files, do the cleanup and then reboot.
Although I'm 100% with the other advisors (give them the points for your immediate issue) ...

... my advice regarding future direction stands. If it is the WinSXS folder, it proves my point perfectly. Putting VHD's on anything but a data only / VHD only drive is susceptible to other services running amok, taking disk space and causing unnecessary downtime.
Lee W, MVPTechnology and Business Process Advisor
Most Valuable Expert 2013

Add drives and NEVER put VHDs on the save drive as the OS.  

Info on the files associated with a VM.
Top Expert 2016

Running hyper-V and having a vhd on the system drive is a red-herring here. Hyper-V machines do add some overhead to the system drive vmm memory files, snapshots and so forth.  For performance reasoning alone put vhd's on a separate spindle (physical drive) than the core O/S.
It is obvious that if 100MB or so is let's say 1GB and your drive is so low on space that 1GB of additional data will cause problems then the drive was too small from the beginning.
Distinguished Expert 2017

Many of us likely have been there, the growth of the data might not have been fully accounted for or grew at a rate not anticipated (either underestimated) or the growth of the firm following the setup was successful thus narrowing the window at which point update/upgrade additional capacity is needed

The spec of the server would shed more light on the situation versus a learned observation.

Guessing the initial foray and the cost likely resulted in a setup of the OS/entire storage as a single RAID 5 volume.
versus the RAID1 + RAID 10 that experience dictates...... though this adds to the expense while those in Managment who pay do not see the "benefit" of buying x disks, but seeing storage of x*capacity/2

hyper-v single VM and the system is running out of space with a FIXED VHD something else is going on, possibly the snapshot/... are being added that consume space unnecessarily.


awesome advice guys. thank you for the help.

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