[linux-lvm] Re: LVM 1.0.3 to LVM 1.0.6 upgrade path on a Redhat 8.0 Production System

[Holger Grothe]

On Wed, Feb 19, 2003 at 07:37:18PM +0000, DJ TweeQ wrote:

> Thanks Christian (really). :) Honestly i did not see any mention of that in 
> the documentation in the HOWTO or any of the docs included with LVM. (Is it 
> really there? because i can't see it) :) But a good point nonetheless. I 
                ^^^^^^^^^^^^^^^^^^^^^^
Hard to believe.

Take lvm 1.0.6. 
- FAQ: Question Q3 and Q9 (and answers).
  Q3: Why am I not able to extend a logical volume?
  Q9: Why are my logical volumes limited to 256 GB in size?
- WHATNEW (What is new in LVM - 1.0.6)
  "o Default PE size for vgcreate is now 32MB"
- man vgcreate
  [...]
     OPTIONS
  [...]
            -s, --physicalextentsize PhysicalExtentSize[kKmMgGtT]
              Sets  the  physical extent size on physical volumes
              of this volume group.  A size suffix (k  for  kilo­
              bytes up to t for terabytes) is optional, megabytes
              is the default if no suffix is present.  Values can
              be  from  8 KB to 16 GB in powers of 2. The default
              of 4 MB causes maximum LV sizes of  ~256GB  because
              as  many  as  ~64k extents are supported per LV. In
              case larger maximum LV sizes  are  needed  (later),
              you  need  to  set the PE size to a larger value as
              well. Later changes of the PE size in  an  existing
              VG are not supported.

> >>You aren't going to get magic-silver-bullet hand-holding support for
> >>free.
> 
> Thanks allmighty Willy should i bow to you? I wasn't expecting 
> magic-silver-bullet hand-holding support. I merely asked the list if there 
> were any differences or issues with upgrading LVM on a Redhat 8 system with 
> it's latest kernel and if there were any issues or differences with the 
> "normal" lvm upgrade path..and if so could someone mention those 
> differences. (Anyone have any comments on that in particular?) :) When i ask 
> for help i don't mean magic-silver-bullet hand-holding help. But i help 
> people for free all the time and so can you and if you don't want to it 
> doesn't mean you have to be a smartarse about it. Maybe in your case it does 
> tho huh. But let me ask you something...does it not feel good to help people 
> and make a difference in peoples lives?

Many vendor kernels (e.g Redhat, SuSE) are patched by more than 100 
patches. This fact makes it difficult to integrate "mainstream patches" 
from developers in such vendor kernels without pain. To overcome you have 
two (four) realistic choices
  - use a vanilla kernel instead of the vendor kernel
  - ask your vendor for a kernel which fits your needs
(  - change your distribution
   - try to patch the vendor kernel by yourself)

You already got the first two answers.

Holger
-- 
Holger Grothe  (Email: grothe at mathematik.tu-darmstadt.de)
Fachbereich Mathematik, TU Darmstadt