re[2]: [linux-lvm] What are they talking about?

re[2]: [linux-lvm] What are they talking about?

[Greg Freemyer]

Kevin,

I understand how LVM2, DM, and EVMS are architected.

I still have no idea what the article is talking about.

Are you saying that the referenced sources just don't understand how it all works 
and that the "industrial-strength Logical Volume Manager" they want is achievable via
the current DM implementation in combination with appropriate high quality 
user-space tools?

That certainly agrees with what I thought and why I was so confused by the article.

Thanks
Greg
-- 
Greg Freemyer


 >>  (Once more - with feeling this time!)

 >>  Device-Mapper is the new kernel driver in 2.5. It replaced the LVM1 kernel
 >>  
 >>  driver from 2.4. This driver provides generic "volume management" 
 >>  capabilities. Specifically, it can create devices which simply redirect
 >>  I/O 
 >>  to other underlying devices. Such a device could be thought of as a
 >>  "logical 
 >>  volume".

 >>  LVM2 and EVMS are both actively developed projects that utilize the 
 >>  Device-Mapper driver for creating their "logical volumes". Neither LVM2
 >>  nor 
 >>  EVMS are (or will be) "in the kernel". All of the real complexity of
 >>  volume 
 >>  management is done in user-space. It is far more sensible to ask a
 >>  question 
 >>  like "will LVM2 and/or EVMS be included in the next release of Red Hat or 
 >>  Debian?" And the next major release of these distros may not correspond 
 >>  exactly with the release of the 2.6.0 kernel.

 >>  To prevent reposting all of the gory details, please see a very similar 
 >>  previous discussion at:
 >>  http://marc.theaimsgroup.com/?t=104164610600002&r=1&w=2
 >>  and
 >>  http://marc.theaimsgroup.com/?t=104195031700002&r=1&w=2


 >>  On Wednesday 21 May 2003 12:42, Anastasios A. Papadopoulos \(Tas\) wrote:
 >>  > Now I am really confused.  (Sorry folks, it doesn't take much).
 >>  >
 >>  > I thought that EVMS was dead.  The EVMS web site says something to the
 >>  > effect that the new EVMS product will be mostly a front end for (LVM?). 
 >>  Am
 >>  > I reading that wrong?
 >>  >
 >>  > Also in their announcement, the EVMS development group said that Linus
 >>  etal
 >>  > decided to include LVM but not EVMS.
 >>  >
 >>  > Can someone straighten me out, please?
 >>  >
 >>  > Thanks
 >>  >
 >>  > ----- Original Message -----
 >>  > From: "Greg Freemyer" <freemyer@NorcrossGroup.com>
 >>  > To: "LVM Mailing list" <linux-lvm@sistina.com>
 >>  > Sent: Wednesday, May 21, 2003 1:06 PM
 >>  > Subject: [linux-lvm] What are they talking about?
 >>  >
 >>  >
 >>  > In the article at http://www.eweek.com/article2/0,3959,1054003,00.asp
 >>  >
 >>  > they talk about the 2.6 kernel having a DM, but not a LVM.
 >>  >
 >>  > What are they trying to say?  What is it they think is missing?
 >>  >
 >>  > === Quote from the article
 >>  >
 >>  > According to Witham, a number of features that the development community
 >>  > believes are not yet ready to be incorporated into the 2.6 kernel may
 >>  very
 >>  > well be pushed to 2.7.
 >>  >
 >>  > Among these features are support for complete Non-Uniform Memory Access
 >>  > as well as an EVMS (Enterprise Volume Management System), which deals
 >>  > with the difficult and controversial issue of volume management, Frye
 >>  said,
 >>  > adding that 2.6 would be better than 2.4 in terms of volume management
 >>  even
 >>  > without the EVMS.
 >>  >
 >>  > Oracle Corp. and Red Hat Inc. officials have also previously called for
 >>  > volume
 >>  > management. Wim Coekaerts, principal member of Oracle's technical staff,
 >>  in
 >>  > Redwood Shores, Calif., said: "We would like Linux to have a Logical
 >>  Volume
 >>  > Manager. The 2.6 kernel will have a device manager, but we need an LVM."
 >>  >
 >>  > Paul Cornier, executive vice president of Red Hat, in Raleigh, N.C.,
 >>  > agreed.
 >>  >
 >>  > "Making a more generic cluster file system is important to us, as is an
 >>  > industrial-strength Logical Volume Manager," Cornier said. "A
 >>  distributed
 >>  > lock
 >>  > manager completes things. This is functionality that needs to go into
 >>  the
 >>  > operating
 >>  > system but is unlikely to be found in the next [kernel] upgrade."
 >>  >
 >>  > IBM's Frye said that there's clearly a need for an improved volume
 >>  > management
 >>  > system and that Linux is not yet good enough in that regard.
 >>  > ====
 >>  >
 >>  > Thanks
 >>  > Greg
 >>  > --
 >>  > Greg Freemyer

 >>  -- 
 >>  Kevin Corry
 >>  kevcorry@us.ibm.com
 >>  http://evms.sourceforge.net/


 >>  _______________________________________________
 >>  linux-lvm mailing list
 >>  linux-lvm@sistina.com
 >>  http://lists.sistina.com/mailman/listinfo/linux-lvm
 >>  read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] What are they talking about?

[Kevin Corry]

On Wednesday 21 May 2003 15:53, Greg Freemyer wrote:
> Kevin,
>
> I understand how LVM2, DM, and EVMS are architected.
>
> I still have no idea what the article is talking about.
>
> Are you saying that the referenced sources just don't understand how it all
> works and that the "industrial-strength Logical Volume Manager" they want
> is achievable via the current DM implementation in combination with
> appropriate high quality user-space tools?

Yes, that would be my opinion. DM provides all of the infrastructure that the 
kernel requires. (It can be further enhanced by adding sub-modules 
("targets") to provide new ways to map devices). Then it's up to the 
user-space tools to figure out how to best use this infrastructure.

> That certainly agrees with what I thought and why I was so confused by the
> article.

I was quite confused by the article as well. :)

-- 
Kevin Corry
kevcorry@us.ibm.com
http://evms.sourceforge.net/

Re: [linux-lvm] What are they talking about?

[Alasdair G Kergon]

On Wed, May 21, 2003 at 04:53:23PM -0400, Greg Freemyer wrote:
> I still have no idea what the article is talking about.

Ask the author?

Try to imagine you never read it?

Alasdair
-- 
agk@uk.sistina.com

Re: [linux-lvm] What are they talking about?

[Steve Pratt]

>Now I am really confused.  (Sorry folks, it doesn't take much).

>I thought that EVMS was dead.  The EVMS web site says something to the
>effect that the new EVMS product will be mostly a front end for (LVM?).
Am
>I reading that wrong?

No, EVMS is alive and well. EVMS was converted to use Device Mapper but and
adds on lots of new features such as File System coordination and
integration with MD (RAID support).

>Also in their announcement, the EVMS development group said that Linus
etal
>decided to include LVM but not EVMS.

Nope, LVM was removed from 2.5(6) kernel and replaced with DM (device
mapper).  Both EVMS and LVM2 (user tools) now use Device Mapper as threir
main kernel component.

>Can someone straighten me out, please?

Just did.

>Thanks

Welcome.

p.s.  Please ignore all the comments by Dan Frye about EVMS, he is
mistaken.

Steve

[linux-lvm] What are they talking about?

[Greg Freemyer]

In the article at http://www.eweek.com/article2/0,3959,1054003,00.asp

they talk about the 2.6 kernel having a DM, but not a LVM.

What are they trying to say?  What is it they think is missing?

=== Quote from the article
 
According to Witham, a number of features that the development community 
believes are not yet ready to be incorporated into the 2.6 kernel may very well be pushed to 2.7.

Among these features are support for complete Non-Uniform Memory Access 
as well as an EVMS (Enterprise Volume Management System), which deals 
with the difficult and controversial issue of volume management, Frye said, 
adding that 2.6 would be better than 2.4 in terms of volume management even 
without the EVMS.

Oracle Corp. and Red Hat Inc. officials have also previously called for volume 
management. Wim Coekaerts, principal member of Oracle's technical staff, in 
Redwood Shores, Calif., said: "We would like Linux to have a Logical Volume 
Manager. The 2.6 kernel will have a device manager, but we need an LVM."

Paul Cornier, executive vice president of Red Hat, in Raleigh, N.C., agreed.

"Making a more generic cluster file system is important to us, as is an 
industrial-strength Logical Volume Manager," Cornier said. "A distributed lock 
manager completes things. This is functionality that needs to go into the operating 
system but is unlikely to be found in the next [kernel] upgrade."

IBM's Frye said that there's clearly a need for an improved volume management 
system and that Linux is not yet good enough in that regard.
====

Thanks
Greg
-- 
Greg Freemyer
  

Re: [linux-lvm] What are they talking about?

[Anastasios A. Papadopoulos (Tas)]

Now I am really confused.  (Sorry folks, it doesn't take much).

I thought that EVMS was dead.  The EVMS web site says something to the
effect that the new EVMS product will be mostly a front end for (LVM?).  Am
I reading that wrong?

Also in their announcement, the EVMS development group said that Linus etal
decided to include LVM but not EVMS.

Can someone straighten me out, please?

Thanks

----- Original Message -----
From: "Greg Freemyer" <freemyer@NorcrossGroup.com>
To: "LVM Mailing list" <linux-lvm@sistina.com>
Sent: Wednesday, May 21, 2003 1:06 PM
Subject: [linux-lvm] What are they talking about?


In the article at http://www.eweek.com/article2/0,3959,1054003,00.asp

they talk about the 2.6 kernel having a DM, but not a LVM.

What are they trying to say?  What is it they think is missing?

=== Quote from the article

According to Witham, a number of features that the development community
believes are not yet ready to be incorporated into the 2.6 kernel may very
well be pushed to 2.7.

Among these features are support for complete Non-Uniform Memory Access
as well as an EVMS (Enterprise Volume Management System), which deals
with the difficult and controversial issue of volume management, Frye said,
adding that 2.6 would be better than 2.4 in terms of volume management even
without the EVMS.

Oracle Corp. and Red Hat Inc. officials have also previously called for
volume
management. Wim Coekaerts, principal member of Oracle's technical staff, in
Redwood Shores, Calif., said: "We would like Linux to have a Logical Volume
Manager. The 2.6 kernel will have a device manager, but we need an LVM."

Paul Cornier, executive vice president of Red Hat, in Raleigh, N.C., agreed.

"Making a more generic cluster file system is important to us, as is an
industrial-strength Logical Volume Manager," Cornier said. "A distributed
lock
manager completes things. This is functionality that needs to go into the
operating
system but is unlikely to be found in the next [kernel] upgrade."

IBM's Frye said that there's clearly a need for an improved volume
management
system and that Linux is not yet good enough in that regard.
====

Thanks
Greg
--
Greg Freemyer


_______________________________________________
linux-lvm mailing list
linux-lvm@sistina.com
http://lists.sistina.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] What are they talking about?

[Kevin Corry]

(Once more - with feeling this time!)

Device-Mapper is the new kernel driver in 2.5. It replaced the LVM1 kernel 
driver from 2.4. This driver provides generic "volume management" 
capabilities. Specifically, it can create devices which simply redirect I/O 
to other underlying devices. Such a device could be thought of as a "logical 
volume".

LVM2 and EVMS are both actively developed projects that utilize the 
Device-Mapper driver for creating their "logical volumes". Neither LVM2 nor 
EVMS are (or will be) "in the kernel". All of the real complexity of volume 
management is done in user-space. It is far more sensible to ask a question 
like "will LVM2 and/or EVMS be included in the next release of Red Hat or 
Debian?" And the next major release of these distros may not correspond 
exactly with the release of the 2.6.0 kernel.

To prevent reposting all of the gory details, please see a very similar 
previous discussion at:
http://marc.theaimsgroup.com/?t=104164610600002&r=1&w=2
and
http://marc.theaimsgroup.com/?t=104195031700002&r=1&w=2


On Wednesday 21 May 2003 12:42, Anastasios A. Papadopoulos \(Tas\) wrote:
> Now I am really confused.  (Sorry folks, it doesn't take much).
>
> I thought that EVMS was dead.  The EVMS web site says something to the
> effect that the new EVMS product will be mostly a front end for (LVM?).  Am
> I reading that wrong?
>
> Also in their announcement, the EVMS development group said that Linus etal
> decided to include LVM but not EVMS.
>
> Can someone straighten me out, please?
>
> Thanks
>
> ----- Original Message -----
> From: "Greg Freemyer" <freemyer@NorcrossGroup.com>
> To: "LVM Mailing list" <linux-lvm@sistina.com>
> Sent: Wednesday, May 21, 2003 1:06 PM
> Subject: [linux-lvm] What are they talking about?
>
>
> In the article at http://www.eweek.com/article2/0,3959,1054003,00.asp
>
> they talk about the 2.6 kernel having a DM, but not a LVM.
>
> What are they trying to say?  What is it they think is missing?
>
> === Quote from the article
>
> According to Witham, a number of features that the development community
> believes are not yet ready to be incorporated into the 2.6 kernel may very
> well be pushed to 2.7.
>
> Among these features are support for complete Non-Uniform Memory Access
> as well as an EVMS (Enterprise Volume Management System), which deals
> with the difficult and controversial issue of volume management, Frye said,
> adding that 2.6 would be better than 2.4 in terms of volume management even
> without the EVMS.
>
> Oracle Corp. and Red Hat Inc. officials have also previously called for
> volume
> management. Wim Coekaerts, principal member of Oracle's technical staff, in
> Redwood Shores, Calif., said: "We would like Linux to have a Logical Volume
> Manager. The 2.6 kernel will have a device manager, but we need an LVM."
>
> Paul Cornier, executive vice president of Red Hat, in Raleigh, N.C.,
> agreed.
>
> "Making a more generic cluster file system is important to us, as is an
> industrial-strength Logical Volume Manager," Cornier said. "A distributed
> lock
> manager completes things. This is functionality that needs to go into the
> operating
> system but is unlikely to be found in the next [kernel] upgrade."
>
> IBM's Frye said that there's clearly a need for an improved volume
> management
> system and that Linux is not yet good enough in that regard.
> ====
>
> Thanks
> Greg
> --
> Greg Freemyer

-- 
Kevin Corry
kevcorry@us.ibm.com
http://evms.sourceforge.net/