Re: lvm2 - question about pvmove
On Mon, Jul 13, 2009 at 10:41 AM, Ron Johnson<ron.l.johnson@cox.net> wrote:
>>
>
> What if I want 4 "small" partitions instead of one monster 1TB partition?
> I've read that you need a target at least as large as the source.
>
> (I've got this aching feeling that 1TB partitions are just not a good idea,
> and that granularity is always a good idea...)
It makes no sense to have multiple LVM partitions on the same disk,
just to put them back together again as one big volume group. I mean,
what's the purpose of using LVM in the first place then?
No. Partition the disk into one swap + one LVM.
Then use the LVM stuff to parcel out the space to various file systems.
The only case that I could see for partitioning the drive into
multiple LVM chunks would be if you want to experiment with using the
LVM commands like pvmove and you only have one disk.
For example, I have one machine with four disks, two 500GB and two
1TB. The partition schemes on those are:
/dev/sda1 1 17 136521 82 Linux swap / Solaris
/dev/sda2 18 121601 976623480 8e Linux LVM
/dev/sdb1 1 17 136521 82 Linux swap / Solaris
/dev/sdb2 18 121601 976623480 8e Linux LVM
/dev/sdc1 1 17 136521 82 Linux swap / Solaris
/dev/sdc2 18 60801 488247480 8e Linux LVM
/dev/sdd1 1 17 136521 82 Linux swap / Solaris
/dev/sdd2 18 60801 488247480 8e Linux LVM
That gives me a VG of 2.73TB, which I have partitioned out into into a
number of LVs of all sorts of different sizes:
thune:~# lvdisplay | grep LV.Size
LV Size 300.00 GB
LV Size 128.00 GB
LV Size 70.00 GB
LV Size 5.00 GB
LV Size 512.00 MB
LV Size 16.00 GB
LV Size 1.00 GB
LV Size 14.00 GB
LV Size 1.94 TB
LV Size 20.00 GB
LV Size 25.00 GB
Hmmm.. . I wonder what that 1GB one is....
One my other machine, it's similar, only with less swap across spindles:
/dev/sda1 1 182401 1465136001 8e Linux LVM
/dev/sdb1 1 17 136521 82 Linux swap / Solaris
/dev/sdb2 18 121601 976623480 8e Linux LVM
For another 2.27TB with:
LV Size 8.00 GB
LV Size 15.00 GB
LV Size 800.00 GB
LV Size 200.00 GB
LV Size 200.00 GB
LV Size 200.00 GB
LV Size 900.00 GB
Nothing wrong with big disk partitions (fdisk); just break it up into
smaller LVs
mrc
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