Re: [gentoo-user] lvm2/external partitions question

[Dirk Heinrichs]

Am Dienstag, 30. August 2005 08:49 schrieb ext W.Kenworthy:
> Comments inline:
>
> moriah ~ # df -h
> Filesystem            Size  Used Avail Use% Mounted on
> udev                  252M  2.6M  249M   2% /dev

Hmm, mine takes 116k, how comes your /dev uses 2.6M?

> cachedir              3.8G  2.2G  1.6G  59% /lib/splash/cache

This looks to be the same as /, what is it good for, could you explain this?

> /dev/vg1/usr           32G  5.9G   27G  19% /usr
> /dev/vg1/var           48G  2.3G   46G   5% /var

I doubt you'll ever get them filled.

> /dev/vg1/tmp           16G   33M   16G   1% /tmp

I use tmpfs for this, but that really depends.

> /dev/vg1/home          77G   26G   52G  34% /home

As said before I prefer per-user volumes (and use the automounter to mount 
them on demand).

> On Tue, 2005-08-30 at 07:49 +0200, Dirk Heinrichs wrote:
> > Am Dienstag, 30. August 2005 06:28 schrieb ext Mark Knecht:
> > >    That's very helpful. To test my understanding
> > >
> > > /dev/hda1 - boot - 100M
> >
> > Way too much.
>
> only if you are using for nothing else but kernels - as mentioned in my
> prev. I intended using it for storage as well as booting.
>
> > > /dev/hda2 - swap - 2G
> >
> > Can be on a logical volume, too.
>
> I have seen warnings against doing this due to poor performance

Do you have any real numbers?

> > > /dev/hda3 - NOT CLEAR - the backup/rescue install?
> >
> > Why? Use the LiveCD.
>
> Some machines dont have a CD.  A liveCD also doesnt run squid with my
> setup, a mailfiltering gateway or my particular firewall configuration
> and so on so its either useless, or means extensive downtime to
> reconfigure.  For pure rescue, or a limited desktop a liveCD is fine
> (and generally knoppix is superior anyway for a desktop)
> only if you are using for nothing else but kernels - as mentioned in my
> prev. I intended using it for storage as well as booting.

OK, depending on the use of the machine, it may be useful, but Mark didn't 
tell. So I wanted to show another way.

> > > /dev/hda5 - root - 4G
> >
> > Can also be on a logical volume, but needs an initrd/initramfs. 4G is
> > too large, IMHO. Mine is 256M.
>
> As you can see, I already use 2.2G of the root (and 2.9G on another
> system), and sometimes much more - so 256M isnt going to get me far!

I wonder what else to put on / that couldn't be on a separate volume? / has 
everything to get things set up, nothing more nothing less. If I'd need a 
rescue system, I would rsync my current / to a separate volume/partition 
and change one line in /etc/fstab on the clone and add an entry for it to 
grub conf.

> Set it to your own particular requirements.  I dont use initrd's - too
> flakey, extra work thats not needed in most cases.  I decided in my
> early experiments to limit LVM for data on the partitions that cause me
> grief with space so most of the root partitions including /etc and /lib
> are on a base filesystem (/)  This can simplify working on the system.
> It is possible to use LVM for nearly everything, but there's extra
> complexity, and warnings about some configurations.
>
> Small roots used to be the way in the old days, but the number of
> machines that crashed due to running out of root space were legion!

As you can see below, even my 256M are too much, only 52% are used and it 
didn't change much for years. Even if I would run out of space on /, I 
could simply grow it (and since it's a lv, with reiserfs on it, it can be 
done online).

> > Sizes:
> > # df -h|grep evms
> > /dev/evms/root        256M  132M  125M  52% /

Bye...

	Dirk
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