From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1Rjglg-000263-Vx for garchives@archives.gentoo.org; Sun, 08 Jan 2012 00:37:49 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 55B8921C03F; Sun, 8 Jan 2012 00:37:34 +0000 (UTC) Received: from svr-us4.tirtonadi.com (svr-us4.tirtonadi.com [69.65.43.212]) by pigeon.gentoo.org (Postfix) with ESMTP id 9600F21C021 for ; Sun, 8 Jan 2012 00:36:22 +0000 (UTC) Received: from mail-we0-f181.google.com ([74.125.82.181]) by svr-us4.tirtonadi.com with esmtpsa (TLSv1:RC4-SHA:128) (Exim 4.69) (envelope-from ) id 1RjgkI-001MRS-0L for gentoo-user@lists.gentoo.org; Sun, 08 Jan 2012 07:36:22 +0700 Received: by werm12 with SMTP id m12so2410629wer.40 for ; Sat, 07 Jan 2012 16:36:18 -0800 (PST) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.180.88.229 with SMTP id bj5mr15797024wib.5.1325982978397; Sat, 07 Jan 2012 16:36:18 -0800 (PST) Received: by 10.223.83.12 with HTTP; Sat, 7 Jan 2012 16:36:18 -0800 (PST) Received: by 10.223.83.12 with HTTP; Sat, 7 Jan 2012 16:36:18 -0800 (PST) In-Reply-To: References: <1325937084.37030@rumba> <4F084B8B.4080104@persimplex.net> Date: Sun, 8 Jan 2012 07:36:18 +0700 Message-ID: Subject: Re: [gentoo-user] gentoo-sources and xen blktap driver? From: Pandu Poluan To: gentoo-user@lists.gentoo.org Content-Type: multipart/alternative; boundary=f46d0442674067d58a04b5f97875 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - svr-us4.tirtonadi.com X-AntiAbuse: Original Domain - lists.gentoo.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - poluan.info X-Archives-Salt: 0e684c9b-4d79-4b2b-b3f2-ecd0fd177447 X-Archives-Hash: 27013ecc6d14466a50f793a4cd9deb74 --f46d0442674067d58a04b5f97875 Content-Type: text/plain; charset=UTF-8 On Jan 8, 2012 12:43 AM, "Michael Mol" wrote: > > On Sat, Jan 7, 2012 at 11:35 AM, Pandu Poluan wrote: > > On Jan 7, 2012 8:44 PM, "victor romanchuk" wrote: > >> > >> Konstantinos Agouros wrote, at 01/07/2012 03:51 PM: > >> > since xen got into the mainstream kernel the way to go is to use > >> > gentoo-sources for dom0 and the domUs. However the blktap modules are > >> > not > >> > there. Is there any way to get this to work? > >> > >> blktap drivers were excluded from kernel mainline since 3.x, these two > >> threads > >> from xen-users mailing list might put some light in that context: > >> > >> > >> http://old-list-archives.xen.org/archives/html/xen-users/2011-07/msg00637.html > >> > >> http://old-list-archives.xen.org/archives/html/xen-users/2011-10/msg00065.html > >> > >> the latest sys-kernel/xen-sources containing working blktap (not blktap2) > >> is > >> 2.6.38 (this is buggy from my point of view; i'm still sitting on > >> 2.6.34-r5 for > >> production installations) > >> > > > > Can someone shed a light on the importance of blktap, i.e., why one would > > want to use it when -- as someone explained in the first email thread you > > gave -- blkfront+blkend is enough for paravirtualization? > > Reading through the linked threads, it sounds like the benefit stems > from being able to shim things in between the front and back ends. > > You might want that for any number of reasons: > * a block encryption layer > * a metering layer > * a read/write masking layer > * an intercept to have the block device exist on (or be mirrored to) > on another system. > > etc. > Ah yes, of course. One of the threads also mentioned that blktap might be better implemented in userspace. Rgds, --f46d0442674067d58a04b5f97875 Content-Type: text/html; charset=UTF-8


On Jan 8, 2012 12:43 AM, "Michael Mol" <mikemol@gmail.com> wrote:
>
> On Sat, Jan 7, 2012 at 11:35 AM, Pandu Poluan <pandu@poluan.info> wrote:
> > On Jan 7, 2012 8:44 PM, "victor romanchuk" <rom@persimplex.net> wrote:
> >>
> >> Konstantinos Agouros wrote, at 01/07/2012 03:51 PM:
> >> > since xen got into the mainstream kernel the way to go is to use
> >> > gentoo-sources for dom0 and the domUs. However the blktap modules are
> >> > not
> >> > there. Is there any way to get this to work?
> >>
> >> blktap drivers were excluded from kernel mainline since 3.x, these two
> >> threads
> >> from xen-users mailing list might put some light in that context:
> >>
> >>
> >> http://old-list-archives.xen.org/archives/html/xen-users/2011-07/msg00637.html
> >>
> >> http://old-list-archives.xen.org/archives/html/xen-users/2011-10/msg00065.html
> >>
> >> the latest sys-kernel/xen-sources containing working blktap (not blktap2)
> >> is
> >> 2.6.38 (this is buggy from my point of view; i'm still sitting on
> >> 2.6.34-r5 for
> >> production installations)
> >>
> >
> > Can someone shed a light on the importance of blktap, i.e., why one would
> > want to use it when -- as someone explained in the first email thread you
> > gave -- blkfront+blkend is enough for paravirtualization?
>
> Reading through the linked threads, it sounds like the benefit stems
> from being able to shim things in between the front and back ends.
>
> You might want that for any number of reasons:
> * a block encryption layer
> * a metering layer
> * a read/write masking layer
> * an intercept to have the block device exist on (or be mirrored to)
> on another system.
>
> etc.
>

Ah yes, of course.

One of the threads also mentioned that blktap might be better implemented in userspace.

Rgds,

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