From: Jason Dillaman <jdillama@redhat.com>
To: Bobby <italienisch1987@gmail.com>
Cc: Ilya Dryomov <idryomov@gmail.com>, dev <dev@ceph.io>,
ceph-devel <ceph-devel@vger.kernel.org>
Subject: Re: multiple BLK-MQ queues for Ceph's RADOS Block Device (RBD) and CephFS
Date: Thu, 16 Jul 2020 16:11:45 -0400 [thread overview]
Message-ID: <CA+aFP1Am-dQCrd-itiZo5CKEJK44PQzgZR2YuEKkLqU5v_XW=w@mail.gmail.com> (raw)
In-Reply-To: <CA+xD70MyfKgn5m3=JvgFfg+Ww=T8eJ2b9bogdbS4ogYAifNCTw@mail.gmail.com>
On Thu, Jul 16, 2020 at 3:19 PM Bobby <italienisch1987@gmail.com> wrote:
>
> Hi,
>
> I completely agree to what you said regarding Ceph client. This is exactly my understanding of a Ceph client.
>
> And regarding blk-mq, I meant for a block device. A multi-queue implementation of a block device.
krbd is a blk-mq implementation of a block device. So is the nbd block
device driver -- which can be combined w/ rbd-nbd (or any other NBD
server) to utilize librbd in user-space.
> On Wednesday, July 15, 2020, Ilya Dryomov <idryomov@gmail.com> wrote:
> > On Wed, Jul 15, 2020 at 12:47 AM Bobby <italienisch1987@gmail.com> wrote:
> >>
> >>
> >>
> >> Hi Ilya,
> >>
> >> Thanks for the reply. It's basically both i.e. I have a specific project currently and also I am looking to make ceph-fuse faster.
> >>
> >> But for now, let me ask specifically the project based question. In the project I have to write a blk-mq kernel driver for the Ceph client machine. The Ceph client machine will transfer the data to HBA or lets say any embedded device.
> >
> > What is a "Ceph client machine"?
> >
> > A Ceph client (or more specifically a RADOS client) speaks RADOS
> > protocol and transfers data to OSD daemons. It can't transfer data
> > directly to a physical device because something has to take care of
> > replication, ensure consistency and self healing, etc. This is the
> > job of the OSD.
> >
> >>
> >> My hope is that there can be an alternative and that alternative is to not implement a blk-mq kernel driver and instead do the stuff in userspace. I am trying to avoid writing a blk-mq kernel driver and yet achieve the multi-queue implementation through userspace. Is it possible?
> >>
> >> Also AFAIK, the Ceph’s block storage implementation uses a client module and this client module has two implementations librbd (user-space) and krbd (kernel module). I have not gone deep into these client modules. but can librbd help me with this?
> >
> > I guess I don't understand the goal of your project. A multi-queue
> > implementation of what exactly? A Ceph block device, a Ceph filesystem
> > or something else entirely? It would help if you were more specific
> > because "a multi-queue driver for Ceph" is really vague.
> >
> > Thanks,
> >
> > Ilya
> > _______________________________________________
> Dev mailing list -- dev@ceph.io
> To unsubscribe send an email to dev-leave@ceph.io
--
Jason
prev parent reply other threads:[~2020-07-16 20:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-13 18:40 multiple BLK-MQ queues for Ceph's RADOS Block Device (RBD) and CephFS Bobby
2020-07-14 21:16 ` [Ceph-qa] " Ilya Dryomov
[not found] ` <CA+xD70Neac2hpzu-Tg7s+1NCDegwzKs-zdTk8DYTWZPjNaexaA@mail.gmail.com>
2020-07-15 19:04 ` Ilya Dryomov
[not found] ` <CA+xD70MyfKgn5m3=JvgFfg+Ww=T8eJ2b9bogdbS4ogYAifNCTw@mail.gmail.com>
2020-07-16 20:11 ` Jason Dillaman [this message]
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='CA+aFP1Am-dQCrd-itiZo5CKEJK44PQzgZR2YuEKkLqU5v_XW=w@mail.gmail.com' \
--to=jdillama@redhat.com \
--cc=ceph-devel@vger.kernel.org \
--cc=dev@ceph.io \
--cc=dillaman@redhat.com \
--cc=idryomov@gmail.com \
--cc=italienisch1987@gmail.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.