Windows hosts : partitions not fully used

[fcambot]

Hi,

i have several virtual windows 2008 R2 , with partition uselessly larges. I was wondering if i would gain some time by shrinking partition to a smaller size.

[Shestakov]

Hi Florian,
Could you clarify your question?
I suppose your backup jobs take more time than they could because of not erased data on the partitions of your VMs. And you are wondering if shrinking of the partitions can decrease time of backup jobs. Is that correct?
Do you have thin or thick type of disks provisioning?
Thank you.

[fcambot]

That's exactly what you said .
I have thick provisionend disks, and i use frequently sdelete.

[Shestakov]

Great!

So, after using sdelete, is your backup size somewhere around your disk`s capacity or disk usage space? Try to do Active Full backup after sdelete and see if it changes the size of backup, hence time of backup job.

i have several virtual windows 2008 R2 , with partition uselessly larges. I was wondering if i would gain some time by shrinking partition to a smaller size

If you think your partitions are too large, for sure you can shrink them. Are you going to shrink partitions, but keep the same total size of VM disks or you are going to decrease a size of your VM by shrinking partitions?
This post can also give you some tips, please take a look.

Thank you.

[fcambot]

I created a disk with just enough size, moved data and deleted "old" disk.
Looks like my backup became smaller , i just checked two fulkl backups, before/after shrink.
What i wondered was if the non-allocated space on the partition was treated or not, it looks like it's treated and take room.

[Shestakov]

Good to know!

When you start the backup job Veeam B&R reads VM`s virtual disk blocks and skips zeroed blocks. If you've never used this unallocated disk space, then these blocks will be skipped.

[fcambot]

However, yhey've been used and zeroed.

[Shestakov]

However, yhey've been used and zeroed.

What do you mean by "used"? Did you mean zeroed unallocated space of the disk was backed up?
If yes, how did you make this conclusion? Could you please provide job stats?
Thanks.

[fcambot]

To be sure, I tried every combinations:
40GB + 40Gb vm
Extending 2nd disk to 80Gb without enlarging partition
Enlarging partition + sdelete
Shrinking partition

and every backup has the same size.
So if sectors are zeroed, and partition is shrinked, backups will be smaller permanently.
I have databases which tend to "spill" data on disks, giving them just enough space by shrinking partitions seems to be a good idea.

Love this product

[Shestakov]

Hi Florian,

I`m glad you enjoy the product!

Actually if you are taking backup of a VM it doesn`t matter how many partitions you have there, while the size of the VM is more important, since Veeam B&R VM takes an image of the VM. That`s why I asked you about your plan: "Are you going to shrink partitions, but keep the same total size of VM disks or you are going to decrease a size of your VM by shrinking partitions?"

Here in the forum were a couple of interesting related topics about thick/thick provisioned disks size and backup size calculation. Please take a look.

Thank you!