Incorrect wsl disk space

[Mystic8b]

# Environment
Platform ServicePack Version      VersionString
-------- ----------- -------      -------------
 Win32NT             10.0.19041.0 Microsoft Windows NT 10.0.19041.0

❯ lsb_release -r
Release:        20.04

❯ cat /proc/version
Linux version 4.19.84-microsoft-standard (oe-user@oe-host) (gcc version 8.2.0 (GCC)) #1 SMP Wed Nov 13 11:44:37 UTC 2019

Steps to reproduce

df -h -> enter

Expected behavior

Free space on wsl corresponds to reality

Actual behavior

Free / occupied space does not correspond to reality

[benhillis]

/dev/sdb is not your C drive, it's a VHD that contains your root filesystem.

[Mystic8b]

Yes, but there should be as much space on it as there is on the current drive, isn’t it?

[therealkenc]

No, because it isn't your drive. There is 250GiB on "it" (by default). Where the "it" here isn't a real drive. It is a virtual block device. The size of the virtual device is 250GiB whether the backing storage for the device lives on a 128 gigabyte ssd or a 128 terrabyte raid array. The size isn't real because the device isn't real.

[Mystic8b]

Where is 250mb here? There 251GB
I understand that this is a virtual device, but it must have a certain size occupied on the disk, as on the disks of virtual machines in a workstation, etc.

[benhillis]

@Mystic8b - I don't see MB anywhere in the screenshot you posted, I might be looking at it wrong but I see.

/dev/sdb size=251G used=2.8G
C:\ size=209G Used=98G

[Mystic8b]

/dev/sdb size=251G used=2.8G
C:\ size=209G Used=98G

Exactly. Where does 251gb come from?
About megabytes, I never said a word

[therealkenc]

Type-o obv. 250 GiB (shows as 251GiB). That number is arbitrary ref #4373.

[Mystic8b]

Okay, therealkenc edited his post, first he wrote 250mib
So you want to say that a 250GB virtual disk with a real free space of 111GB is normal?

[therealkenc]

Very normal. You can have a dozen 250 GiB virtual disks (total of 3TiB of space that doesn't really exist) one 128 GiB SSD. [Which is why this is tag by-design already.]

[benhillis]

@therealkenc is right, the disk is dynamic and that is the maximum size.

[Mystic8b]

benhillis, kapish?

[therealkenc]

Thought of a clearer way to put this. Your ext4 filesystem is ~250GiB. It doesn't resize every time you consume a few more bytes in Windows.

[Mystic8b]

damn, okay, it seems there is an opportunity to reduce the size of this disk, even so.
ty

[benhillis]

This isn't constructive.