[Netkit.users] Huge sparse disk files being create on an ext4 partition

Massimo Rimondini rimondin at dia.uniroma3.it
Wed Oct 18 22:45:44 CEST 2017

Hi Jacinto,

I’m sorry to hear that you are experiencing this problem. I expect this to be also associated with a dramatic performance drop when virtual machines are started.

I would first of all start with a little bit of debugging.

- Please check that the current directory ($PWD) when virtual machines are launched lies on the ext4 filesystem.
- Verify the logical and physical size of .disk files of Netkit virtual machines by using ‘ls -lsh’.
- Verify what happens by forcing the creation of a sparse file usind ‘dd if=/dev/zero of=test-sparse bs=1M count=1 seek=100 conv=sparse’ (check the size of the resulting file again using ‘ls -lsh’).
- Make sure there are no extra layers between the filesystem and the disk (e.g., encryption).

Massimo Rimondini

Sent from iPad

> Il giorno 05 ott 2017, alle ore 02:06, Breno Jacinto <brenojac a gmail.com> ha scritto:
> Hello guys.
>       I'm usig netkit in my classes and we're having problems while creating UML machines given that each hard disk is created as a sparse file of about 10GB. While all machines use ext4 filesystems and in theory these files would not be a problem, that is not the case. 
>      Linux keep counting these files as 10 GB and quickly our machines run out of space. I'm not quite sure how to solve this. The idea would be for Linux count the real space these sparse files occupy, right? Any ideas on how to solve this?
>      BTW, we're all running Ubuntu Linux 16.04 on ext4 partitions. 
> best regards, 
> ---> Breno Jacinto
> ---> Instituto Federal de Educação, Ciência e Tecnologia de Alagoas (IFAL)
> -----> http://www.ifal.edu.br
> ---> Life is Choice. You can choose to be a victim, or anything else you want to be. (Sócrates - Peaceful Warrior) <--
> _______________________________________________
> Netkit.users mailing list
> Netkit.users a list.dia.uniroma3.it
> http://list.dia.uniroma3.it/mailman/listinfo/netkit.users
-------------- parte successiva --------------
Un allegato HTML � stato rimosso...
URL: <http://list.dia.uniroma3.it/pipermail/netkit.users/attachments/20171018/f72bfc73/attachment.html>

More information about the Netkit.users mailing list