From: "Richard W.M. Jones" <rjones@redhat.com>
To: Andreas Dilger <adilger@dilger.ca>
Cc: Theodore Ts'o <tytso@mit.edu>, Eric Blake <eblake@redhat.com>,
linux-ext4@vger.kernel.org, libguestfs@redhat.com,
lersek@redhat.com
Subject: Re: e2fsprogs concurrency questions
Date: Mon, 20 Sep 2021 17:33:26 +0100 [thread overview]
Message-ID: <20210920163326.GA16016@redhat.com> (raw)
In-Reply-To: <24A05FA3-F618-4469-BC0A-E19A425A0E36@dilger.ca>
On Sun, Sep 19, 2021 at 04:39:01AM -0600, Andreas Dilger wrote:
> What I don't understand here is why not just use a network
> filesystem that is explicitly designed for this task (eg. NFS or
> Ganesha on to of ext4)?
nbdkit-ext2-filter is very niche, but it's quite different from
anything NFS can do. For example:
$ nbdkit --filter=ext2 --filter=xz \
curl http://oirase.annexia.org/tmp/disk.img.xz \
ext2file=/disk/fedora-33.img
$ nbdinfo nbd://localhost
protocol: newstyle-fixed without TLS
export="":
export-size: 6442450944
content: DOS/MBR boot sector
uri: nbd://localhost:10809/
contexts:
base:allocation
is_rotational: false
is_read_only: true
can_cache: true
can_df: true
can_fast_zero: false
can_flush: true
can_fua: false
can_multi_conn: false
can_trim: false
can_zero: false
$ guestfish --ro --format=raw -a nbd://localhost -i
[...]
Operating system: Fedora 33 (Thirty Three)
/dev/sda3 mounted on /
/dev/sda2 mounted on /boot
What we're doing here is exporting a compressed ext4 image over HTTP
and then accessing a VM image inside it.
(This is a contrived example but it's similar to something called the
Containerized Data Importer in Kubernetes.)
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html
next prev parent reply other threads:[~2021-09-20 16:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-17 21:06 e2fsprogs concurrency questions Eric Blake
2021-09-19 3:49 ` Theodore Ts'o
2021-09-19 10:39 ` Andreas Dilger
2021-09-20 16:33 ` Richard W.M. Jones [this message]
2021-09-19 12:35 ` Richard W.M. Jones
2021-09-20 2:40 ` Theodore Ts'o
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210920163326.GA16016@redhat.com \
--to=rjones@redhat.com \
--cc=adilger@dilger.ca \
--cc=eblake@redhat.com \
--cc=lersek@redhat.com \
--cc=libguestfs@redhat.com \
--cc=linux-ext4@vger.kernel.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).