Re: Fedora 15, new and exciting plans (LVM issues)
On 11/15/2010 12:00 AM, John Reiser wrote:
On 11/14/2010 01:13 PM, Matt McCutchen wrote:
> On Sun, 2010-11-14 at 13:07 -0800, John Reiser wrote:
>> When I created 14 partitions using a DOS partition label
>> (3 primaries, plus extended containing 10 logical partitions)
>> and gave 6 of the partitions to an LVM setup,
>> then I could not remove one of the partitions from the clutches
>> of the LVM, and use the removed partition for some other purpose
>> (keeping the rest of the LVM going), unless I removed all the LVM
>> from that drive.
>
> vgreduce + pvremove? Did something go wrong when you tried?
vgreduce would not let go of the partition that I wanted to take back,
claiming that the partition was still in use.
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DESCRIPTION
vgreduce allows you to remove one or more *unused* physical volumes
from a volume group. [emphasis added]
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I could not find a way to evict any usage of that partition (transparently
move the information somewhere else in the same LVM) as a prelude to applying
vgreduce. In theory I could have moved all of the LVM onto another drive,
but I wanted to keep the LVM going on that drive, with the same user-visible
information content [there was enough free space], but without using one
particular partition that I had given [loaned] to LVM some time before.
pvmove is the command you need to use before doing a vgreduce. That's
basically what I did with the 30TB system that I mentioned elsewhere in
this thread. This system was partitioned into 10 raid-5 volumes and one of
those acted up when we put the system into production (it was already
pre-filled with data). So what I did was a pvmove to clear out the physical
volume which took a few hours and then I removed the physical volume from
the volume group. The fact that I could do all of this while the system
stayed online and was being used was a real life saver.
Regards,
Dennis