[SOLVED] Fstrim lvm-thin clean the space

[Ivan Gersi]

I have Windows VM machine virtualized from physical machine via virtio.
I had to reduce lvm size to 1TB because I use 2TB disk for migrating (physical server is only 1TB)

root@pve1:/dev/disk# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
data pve twi-aotz-- 1.67t 46.97 1.93
root pve -wi-ao---- 96.00g
swap pve -wi-ao---- <7.53g
vm-100-disk-1 pve Vwi-aotz-- 1000.00g data 80.34

There is one problem...I had about 600GB cams recording in the server, so I delete it and server has only 200GB/1000GB filled. But system still see 80% used capacity. E.g if backup of this machine has about 700GB instead 150GB. How can I clean this space?

--- Logical volume ---
LV Path /dev/pve/vm-100-disk-1
LV Name vm-100-disk-1
VG Name pve
LV UUID 5XDIJk-yljE-muc5-q9jW-NK7X-h0M5-ImYKoO
LV Write Access read/write
LV Creation host, time pve1, 2023-12-21 23:56:27 +0100
LV Pool name data
LV Status available
# open 1
LV Size 1000.00 GiB
Mapped size 80.34%
Current LE 256000
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 252:7

I think I need to use fstrim, but I don`t know how.
When I tried to use fstrim how can I think there is error.

root@pve1:/# fstrim /dev/pve/vm-100-disk-1
fstrim: /dev/pve/vm-100-disk-1: not a directory

How can I need to use fstrim correctly?

 

[Dunuin]

Make sure the virtual disk got its "discard" checkbox enabled. Using "virtio block" is by the way not Windows best practice. This would be "virtio SCSI single" + "SCSI".

Then, in Windows, open your disk optimization window (you will find it in one of the settings tabs when right clicking a partition in the explorer) and tell it to optimize the disk.
There is also a powershell command you could google for trimming a partition.

 

[Ivan Gersi]

I`vè already have changed scsi controller to default (instead virtio), so now I checked discard=on but I thought optimize must do node, not VM. Now, it seems good.

--- Logical volume ---
LV Path /dev/pve/vm-100-disk-1
LV Name vm-100-disk-1
VG Name pve
LV UUID 5XDIJk-yljE-muc5-q9jW-NK7X-h0M5-ImYKoO
LV Write Access read/write
LV Creation host, time pve1, 2023-12-21 23:56:27 +0100
LV Pool name data
LV Status available
# open 1
LV Size 1000.00 GiB
Mapped size 7.64%
Current LE 256000
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 252:7

Thanks for explanation.
Solved