[PVE-User] Creating VM with thin provisioning (please help me understand it).

Mark Adams mark at openvs.co.uk
Thu Mar 5 23:19:39 CET 2020


Gianni provided a great reply (please do go and read the admin
documentation), but let me just follow up to one of your points below.

On Thu, 5 Mar 2020, 19:46 Leandro Roggerone, <leandro at tecnetmza.com.ar>
wrote:

> Dear Mark, you said:
> "Then every virtual disk that is created on that storage type is thin
> provisioned."
> Ok ... good to hear that.
>
> So ... Lets suppose I created 5 VMs about 200Gb each on a 1TB space.
> Im using less than 50% on each VM and now I need  to add a 6th VM ?  Even
> Im using thin storage , I will have no free space.
>

If you have configured everything correctly, then in your 50% scenario you
will have used 500G of your 1T. You should have space for more VMs but like
Gianni said make sure you keep a close eye on utilisation, as running out
of space will be very bad for you.

Also note that you can't retrospectively enable thin provisioning (as a
general rule... there are some manual exceptions). This means that if you
created these 5 vms before you ticked that thin provisioning box, they are
thick provisioned and not thin. Which from what you say about being out of
space with 5 x 200G disks sounds like what you did.

Regards,
Mark

What can I do ?
> a) Should assign minimun capacity during creating time and enlarge later if
> needed ?
> b ) Should I look for unused space among existing  VMs and reduce the disk
> ?
> Please let me know what is your criteria to assign storage to new VM.
> Leandro.
>
>
>
>
> El jue., 5 mar. 2020 a las 13:44, Mark Adams via pve-user (<
> pve-user at pve.proxmox.com>) escribió:
>
> >
> >
> >
> > ---------- Forwarded message ----------
> > From: Mark Adams <mark at openvs.co.uk>
> > To: PVE User List <pve-user at pve.proxmox.com>
> > Cc:
> > Bcc:
> > Date: Thu, 5 Mar 2020 16:43:08 +0000
> > Subject: Re: [PVE-User] Creating VM with thin provisioning (please help
> me
> > understand it).
> > Thin provisioning is set on the storage, it is a checkbox and of course
> it
> > has to be a storage type than can be thin provisioned (ie lvmthin, zfs,
> > ceph etc).
> >
> > Then every virtual disk that is created on that storage type is thin
> > provisioned.
> >
> > Regards,
> > Mark
> >
> > On Thu, 5 Mar 2020, 16:28 Leandro Roggerone, <leandro at tecnetmza.com.ar>
> > wrote:
> >
> > > Hi guys , here i am trying to get used to pve. (I came from VM ware
> > EXSi).
> > > Im used to use "thin provisioning" option in vmware.
> > > It allowed me to set maximum drive space allocation but vm will use
> > > minimum and dynamically grow as guest OS needs
> > > .
> > > How should I accomplish same on pve  ?
> > > I created a VM and set 200GB at the storage capacity but can not set
> any
> > > flag about thin provisioning.
> > > Now , If I list lslbl , it  shows that created VM is taking the 200GB.
> > > root at pve:~# lsblk
> > > NAME                         MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
> > > sda                            8:0    0  5.5T  0 disk
> > > ├─sda1                         8:1    0 1007K  0 part
> > > ├─sda2                         8:2    0  512M  0 part
> > > └─sda3                         8:3    0  3.9T  0 part
> > >   ├─pve-swap                 253:0    0    8G  0 lvm  [SWAP]
> > >   ├─pve-root                 253:1    0  1.2T  0 lvm  /
> > >   ├─pve-data_tmeta           253:2    0 15.8G  0 lvm
> > >   │ └─pve-data-tpool         253:4    0  1.9T  0 lvm
> > >   │   ├─pve-data             253:5    0  1.9T  0 lvm
> > >   │   └─pve-vm--100--disk--0 253:6    0  200G  0 lvm
> > >   └─pve-data_tdata           253:3    0  1.9T  0 lvm
> > >     └─pve-data-tpool         253:4    0  1.9T  0 lvm
> > >       ├─pve-data             253:5    0  1.9T  0 lvm
> > >       └─pve-vm--100--disk--0 253:6    0  200G  0 lvm
> > > sr0                           11:0    1 1024M  0 rom
> > >
> > >
> > > I can see from gui , that is is possible to expand disk.
> > > So ... perhaps I should assign a little storage at beginning and then
> > > manually expand if needed.
> > > Please share your idea about this.
> > > I need to begin creating some VMs and work on them , I dont want to
> > create
> > > in a wrong way and have to destroy later.
> > >
> > > <
> > >
> >
> https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail
> > > >
> > > Libre
> > > de virus. www.avast.com
> > > <
> > >
> >
> https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail
> > > >
> > > <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
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> >
> >
> >
> > ---------- Forwarded message ----------
> > From: Mark Adams via pve-user <pve-user at pve.proxmox.com>
> > To: PVE User List <pve-user at pve.proxmox.com>
> > Cc: Mark Adams <mark at openvs.co.uk>
> > Bcc:
> > Date: Thu, 5 Mar 2020 16:43:08 +0000
> > Subject: Re: [PVE-User] Creating VM with thin provisioning (please help
> me
> > understand it).
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