Shrink guest on hosted platform: Difference between revisions
Shrink guest on hosted platform (view source)
Revision as of 15:08, 27 February 2018
, 27 February 2018→Important
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If you don't have that kind of free disk space then you can skip the zero-ing out part. You can still reclaim space, but it will be less optimal. | If you don't have that kind of free disk space then you can skip the zero-ing out part. You can still reclaim space, but it will be less optimal. | ||
Alternatively you can use the "Partially zero out" trick described below. | Alternatively you can use the "Partially zero out" trick described below. | ||
=== How much free space do you need before shrinking? === | |||
Also please note that you need more free space in order to be able to run the shrinking process. | |||
The shrinking process consists of making a copy of your virtual disk while omitting the zero'd out blocks. | |||
So how much extra space you need depends on how you configured the virtual disk for your Virtual Machine. | |||
If your Virtual Disk is a single file, then your free space requirement can grow up-to the full size of that virtual disk. | |||
If OTOH you are using the split disk scheme where a virtual disk is sliced into multiple files the maximum free space you need is the maximum size a slice can be. Nowadays there's not a fixed slice size, it depends on how big your virtual disk actually is. | |||
The split disk scheme since VMware Workstation 11 (VMware Fusion 7), older version of Workstation/Fusion use a 2GB split disk scheme. | |||
Capacity Extent size | |||
================================ | |||
<=128GB 4GB (increased from 2GB) | |||
>128GB && <2TB Capacity / 32 (so maximum of 32 extents) | |||
>=2TB 2TB | |||
For extra safety I recommend to make sure you have an additional 2GB of free space on top of those requirements as mentioned above. | |||
As side note, this also explains why it is generally recommended at the forum by the regulars to use a split disk scheme over single disk files. | |||
This same problem also exists when you want to commit snapshots. | |||
==== Zero out unused space in a Linux VM ==== | ==== Zero out unused space in a Linux VM ==== | ||