lkml.org 
[lkml]   [2000]   [Feb]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: Assumed LVM constraint (Was: Source Code Release of NWFS 2.0 for 2.2/2.3/2.)
Date
> What constraints?  You can just increase the size of the physical extents by a
> factor of 32 or so, yes?

Correct!

>
> Hans
>
> "Henning P. Schmiedehausen" wrote:
> >
> > jmerkey@timpanogas.com (Jeff V. Merkey) writes:
> >
> > Dear Mr. Merkey,
> >
> > >I would still like to look at this possibility. I sent you the source
> > >code for the nwvp.c modules that do the mirroring almost four months ago
> >
> > I am still waiting for a single byte of source code for Linux showing
> > up on your ftp://207.109.151.240. You talk and talk. Where is the
> > code?
> >
> > If you're so generous in mailing around the source, then I'd really
> > like to take a look at your stuff, I'm in the process of designing a
> > multi-TB server farm and so far I will either go with NetApp or a
> > really stable Linux solution. Reiserfs/LVM seemed to be nice but the
> > LVM has constraints at 256GB.

LVM doesn't have this restriction.

If you choose a Physical Extent size of more than 4MB (which is the default
today) at volume group creation time you are able to address multiple
Terabytes directly today.

BTW: LVM command vgcreate(8) tells you about the constraints implied
by the Physical Extend size and if you don't like them just remove
your new Volume Group and recreate it with corrected Physical Extent size.
This is a question of a minute's work.


Nevertheless with IA32 you are still restricted to a maximum of 1 Terabyte
(2 Terabyte if the kernel is unsigned int/long cast clean) per single
block device.

The LVM therefore is able to deal with up to the possible 128 scsi disk
subsystems each of them up to 2 Terabytes in size (the limits implied
by the 8 bit minor number scheme can be worked arround by devfs and will
disapear anyway in the future). You can add some IDE disks as well 8-{)

All these disk subsystems can be configured into a single Volume Group
giving you a "Virtual Disk" of up to 256 Terabyte in size on IA32 today.

Nevertheless, as i mentioned above, a single Logical Volume becausecan only
have a size of up to 2 Terabytes (1 Terabyte garanteed 8), because its just
another block device.

In theory on 64 bit architectures these constraints should not exist at all.

You'll tell us if they still do, right ;-{)))

Heinz

> >
> > Where is the code you're always talking about?
> >
> > >-- you ignored them. I'll post the source code and you can look it over
> >
> > Please, _do_ it.
> >
> > Regards
> > Henning
> >
> > --
> > Dipl.-Inf. (Univ.) Henning P. Schmiedehausen -- hps@tanstaafl.de
> > TANSTAAFL! Consulting - Unix, Internet, Security
> >
> > Hutweide 15 Fon.: 09131 / 50654-0 "There ain't no such
> > D-91054 Buckenhof Fax.: 09131 / 50654-20 thing as a free Linux"
> >
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to majordomo@vger.rutgers.edu
> > Please read the FAQ at http://www.tux.org/lkml/
>
> --
> Get Linux (http://www.kernel.org) plus ReiserFS
> (http://devlinux.org/namesys). If you sell an OS or
> internet appliance, buy a port of ReiserFS! If you
> need customizations and industrial grade support, we sell them.
>


--

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Systemmanagement CS-TS T-Nova
Entwicklungszentrum Darmstadt
Heinz Mauelshagen Otto-Roehm-Strasse 71c
Senior Systems Engineer Postfach 10 05 41
64205 Darmstadt
mge@EZ-Darmstadt.Telekom.de Germany
+49 6151 886-425
FAX-386
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:56    [W:0.107 / U:0.316 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site