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Re: [linux-lvm] Re: Device-mapper submission for 2.4



Does this mean that EVMS and LVM are merging, as they are both using
device mapper?

clueless newbie,
micah

On Fri, 12 Dec 2003, Jord Tanner wrote:

> 
> Device Mapper 1.00.07 patches against 2.4.23 with no problems. Follow 
> the directections for device mapper at 
> http://evms.sourceforge.net/install/kernel.html
> 
> Jord Tanner
> 
> Yanick Quirion wrote:
> 
> >Hi,
> >
> >Is there a patch for device-mapper for kernel 2.4.23?
> >
> >Thanks
> >
> >Yanick
> >
> > 
> >
> >>-----Original Message-----
> >>From: Alasdair G Kergon [mailto:agk uk sistina com]
> >>Sent: 11 December, 2003 14:48
> >>To: linux-kernel vger kernel org; linux-lvm sistina com
> >>Cc: Paul Jakma; Mike Fedyk; Joe Thornber; Marcelo Tosatti; Linus
> >>   
> >>
> >Torvalds
> > 
> >
> >>Subject: [linux-lvm] Re: Device-mapper submission for 2.4
> >>
> >>On Wed, Dec 10, 2003 at 03:40:07PM -0800, Mike Fedyk wrote:
> >>   
> >>
> >>>On Wed, Dec 10, 2003 at 05:00:43PM +0000, Paul Jakma wrote:
> >>>     
> >>>
> >>>>On Wed, 10 Dec 2003 venom sns it wrote:
> >>>>       
> >>>>
> >>>>>DM is back compatible with LVM1, tested and runs well.
> >>>>>         
> >>>>>
> >>>>What about the patches posted by Joe last (?) week which remove
> >>>>       
> >>>>
> >LVM1
> > 
> >
> >>>>support from 2.6 DM?
> >>>>       
> >>>>
> >>They remove support for the broken version 1 of the device-mapper
> >>ioctl interface.  This is nothing to do with LVM1.
> >>
> >>   
> >>
> >>>If this is what I was reading being discussed a few weeks ago, then
> >>>     
> >>>
> >the
> > 
> >
> >>>support for the LVM1 sysctls/ioctls has/will be removed, so you will
> >>>     
> >>>
> >>have to
> >>   
> >>
> >>>use the DM utilities instead of the old LVM1 utilities.  LVM1
> >>>     
> >>>
> >on-disk
> > 
> >
> >>format
> >>   
> >>
> >>>should still be supported.
> >>>     
> >>>
> >>2.6 does not support LVM1 ioctls.
> >>LVM2 userspace tools and EVMS both support LVM1 on-disk format using
> >>device-mapper.
> >>
> >>
> >>Here's a reference sheet to help clarify the terminology and explain
> >>what's happening.
> >>
> >>LVM1 = Userspace tools + kernel ioctls included in marcelo's 2.4 tree
> >> - LVM1 kernel ioctls are *not* included in or available for 2.6
> >> - LVM1 userspace tools do *not* work with 2.6 kernels
> >>
> >>dm = Kernel driver (GPL) for new volume managers to use.
> >> - Included in Linus's 2.6 kernels.
> >> - Available as a patch for 2.4 kernels from the Sistina website.
> >> - Knows *nothing* about volume manager's on-disk metadata layouts.
> >> - Userspace volume managers (e.g. EVMS and LVM2) communicate via a
> >>   
> >>
> >new
> > 
> >
> >>   ioctl interface.
> >> - This ioctl interface is currently "version 4" and we regard it as
> >>   stable.  [Some enhancements are on the horizon, but nothing that
> >>   breaks existing code/binaries.]
> >> - An old development version of this device-mapper ioctl interface
> >>   
> >>
> >known
> > 
> >
> >>   as "version 1" has problems with it, is deprecated and should be
> >>   removed from kernel trees ASAP.
> >>   Always use "version 4" when building new kernels today.
> >>
> >>libdevmapper = Userspace shared library (LGPL) which wraps a volume
> >>manager
> >>              application interface around the device-mapper ioctls
> >> - Can determine transparently whether the kernel device-mapper is
> >>   
> >>
> >using
> > 
> >
> >>   "version 4" dm ioctl interface or the deprecated "version 1"
> >>   
> >>
> >interface
> > 
> >
> >>   and adapt itself accordingly.  [configure --enable-compat]
> >> - Can only communicate with device-mapper: it cannot use LVM1
> >>   
> >>
> >ioctls.
> > 
> >
> >> - Designed primarily for use by LVM2 tools.  [EVMS does not use it]
> >> - Some parts of the libdevmapper API are not yet stable and are
> >>   
> >>
> >likely
> > 
> >
> >>   to get changed.
> >>
> >>dmsetup = Userspace utility (GPL) which provides full command-line
> >>   
> >>
> >access
> > 
> >
> >>to
> >>         the libdevmapper API.
> >> - Designed for use by shell scripts and for testing and debugging.
> >> - Command line interface may be considered stable.  New features may
> >>   
> >>
> >get
> > 
> >
> >>   added, but we'll try not to break existing commands.
> >>
> >>LVM2 = New Logical Volume Manager command line tools (GPL) designed to
> >>      be backward-compatible with LVM1 and offering new features and
> >>      more flexibility, configurability and stability.
> >> - Supports existing LVM1 on-disk metadata.
> >>   This means you do *not* have to make changes to your existing
> >>   
> >>
> >on-disk
> > 
> >
> >>   LVM1 volumes to switch between using LVM1 and LVM2.
> >> - Uses command lines similar to LVM1.
> >> - By default uses a new on-disk metadata format supporting more
> >>   features than the original LVM1 version.
> >> - Communicates with the device-mapper kernel driver via
> >>   
> >>
> >libdevmapper's
> > 
> >
> >>   API.
> >>
> >>
> >>Miscellaneous points:
> >> - LVM1 uses block major number 58: dm selects one or more major
> >>   
> >>
> >numbers
> > 
> >
> >>   dynamically as required instead.
> >> - LVM1 uses character major number 109: dm selects a misc minor
> >>   
> >>
> >number
> > 
> >
> >>   dynamically instead.
> >> - There's a (non-devfs) script for creating /dev/mapper/control at
> >>   startup (or after dm module load).
> >> - You can use LVM1 tools with unpatched 2.4 kernels.
> >> - You can use LVM2 tools with patched 2.4 and unpatched 2.6 kernels.
> >> - Device-mapper support for snapshots and pvmove is so far released
> >>   only for 2.4.  Patches for 2.6 are being tested.
> >> - Multipath and mirror support are under development for 2.6.
> >>   (Then get back-ported to 2.4.)
> >>
> >>Web download page: http://www.sistina.com/products_lvm_download.htm
> >>
> >>The device-mapper tarball contains:
> >> device-mapper kernel patches - needed only for 2.4;
> >> userspace libdevmapper and dmsetup - needed with all dm kernels.
> >>The LVM2 tarball contains the LVM2 command line tools.
> >>
> >>Development code can be found via:
> >> http://people.sistina.com/~thornber/  (for kernel patches)
> >> http://www.sistina.com/products_CVS.htm  (for userspace code)
> >>
> >>Device-mapper mailing list:
> >> http://lists.sistina.com/mailman/listinfo/dm-devel
> >>
> >>Alasdair
> >>--
> >>agk uk sistina com
> >>
> >>_______________________________________________
> >>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/
> >>   
> >>
> >
> >_______________________________________________
> >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/
> > 
> >
> 
> 
> 
> _______________________________________________
> 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/



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