Re: [Qemu-devel] How do you do when write more than 16TB data to qcow2 on ext4?

[Eric Blake]

On 08/16/2018 03:22 AM, Daniel P. Berrangé wrote:
> On Thu, Aug 16, 2018 at 09:35:52AM +0800, lampahome wrote:
> > We all know there's a file size limit 16TB in ext4 and other fs has their
> > limit,too.
> >
> > If I create an qcow2 20TB on ext4 and write to it more than 16TB. Data more
> > than 16TB can't be written to qcow2.
> >
> > So, is there any better ways to solve this situation?
>
> I'd really just recommend using a different filesystem, in particular XFS
> has massively higher file size limit - tested to 500 TB in RHEL-7, with a
> theoretical max size of 8 EB. It is a very mature filesystem & the default
> in RHEL-7.

Or target raw block devices instead of using a filesystem. LVM works great.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org