Re: Re: [linux-lvm] vgscan not returning

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James:
Thanks a lot for your help.
Although i am still not having any luck. Here is what i did.
I got rid of the many partitions and created a single LVM partition.
Here is how it looks now
================================================================
   Device Boot    Start       End    Blocks   Id  System
/dev/hda1   *         1      1020   8193118+  83  Linux
/dev/hda2          1021      1148   1028160   82  Linux swap
/dev/hda3          1149      2491  10787647+  8e  Linux LVM
================================================================

From that point here is a log of the commands i tried

================================================================
[root@fixx /root]# dd if=/dev/zero of=/dev/hda3 bs=512 count=1
1+0 records in
1+0 records out
[root@fixx /root]# pvcreate /dev/hda3
pvcreate -- ERROR: "/etc/lvmtab" doesn't exist; please run vgscan
[root@fixx /root]# dd if=/dev/zero of=/dev/hda3 bs=512 count=100
100+0 records in
100+0 records out
[root@fixx /root]# pvcreate -v /dev/hda3
pvcreate -- ERROR: "/etc/lvmtab" doesn't exist; please run vgscan

[root@fixx /root]# vgscan -v
vgscan -- removing "/etc/lvmtab" and "/etc/lvmtab.d"
vgscan -- creating empty "/etc/lvmtab" and "/etc/lvmtab.d"
vgscan -- reading all physical volumes (this may take a while...)


================================================================
So as you can see i am unable to run pvcreate as it complains about vgscan.
And again it seems that vgscan is never going to return.

Hoping for some pointers
Thanks
Ali



---- On Thu, 19 Sep 2002, James Hawtin (oolon@ankh.org) wrote:

> 
> 
> On Thu, 19 Sep 2002, Ali Zaidi wrote:
> 
> > Hi:
> > I am a novice with LVM but after going through the man pages and howtos i 
was
> > unable to find a solution to my problem. I am hoping one of you might find 
some
> > time to point me in the right direction.
> >
> > I am trying to setup LVM on a RH box. I run vgscan before i can create the
> > volumes but it never returns. Same thing happens with lvmdiskscan and 
pvscan.
> > Here is a -v and -d output of vgscan
> 
> Ok and now to try to answer your problem....
> 
> Did you do a pvcreate?
> 
> did the disk have existing data on it?
> 
> Try dd to write /dev/zero to the first bit of the partitions you want to
> put into lvm. then do you vgscan which should then return with an error
> saying it found nothing.... you can then use pvcreate on them
> 
> Of course your LAME disk layout could be confusing lvm in which case as a
> work arround just have one lvm partion and use lvm to allocate the disk,
> which is what you should be doing in the first place!
> 
> 
> ------
> 
> And now a few quick questions and answers....
> 
> Q: I can allocate my disk better than LVM!
> 
> A: No you cannot! or rather you can allocate your disk when you
> first get the machine to produce nice continuous partions. YOU CAN DO THIS
> WITH LVM. If you have a brand new volume group and just add partions to
> it they will be continuous with LVM as well.... Don't trust LVM.. you can
> do a pvdisplay to show you this fact!
> 
> A2: Sure, but what happens if you want to remove 2 partions, that are not
> next door to each other, and them make the one big partion... with fdisk
> its a dd nigtmare... with LVM its easy.
> 
> Q: but how can I move my stuff onto another disk... I use DD!
> 
> A: SO? There is nothing special about lvm devices apart from the fact they
> make things easer for you... You want to work that way, make your new
> device using LVM or fdisk and do your dd! But you could save yourself time
> by using pvmove!
> 
> Q: LVM adds a level of indirection to my disk.. surely its better to use
> the real disk
> A: Theoritically yes... but the translation to where on the disk is a
> calculation done on your computer not on the disk the slowest part of the
> operation is pulling stuff from your disk! Think about is a software raid
> faster or slower? Its faster cos the slow part was the disk and now there
> is more than one disk!
> 
> Q: I like to micromanage my disk...
> A: You can do that with LVM if you like or you can let LVM do the best it
> can for you and use your bonus time to go down the pub.
> 
> 
> James
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> 
> 


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