Qn's on setup LVM partitions, useful, overheads?
 

Doing a fresh install and deciding to use LVM, I'd like to know if this is a "more-trouble-than-worth-it" deal as opposed to multiple normal logicals for / /home /tmp /swap ...and a primary /boot; though I'd split up the LVM like that.

The overall usage would involve:
a primary /boot

a full distro split as / /home /tmp /var /swap
encrypted
running a virtualiser(unsure which one!)

a minimal textmode maintenance of same distro all in / plus own /swap
encrypted

a /stuff maybe for backups, big downloads or such

an empty / maybe for a new distro tryout.

Aside from the primary /boot would I be able to have all the rest inside 1 whole LVM partition?

Might it be better to have the maintenance outside the LVM, presuming it can mount the LVM?

I believe there are 2 ways for encrypted LVM:
1)set up an encrypted partition and the LVM goes onto it.
2) do the LVM then encrypt each part/volume.

Number (1) would simplify for just 1 password, though perhaps depending on distro's setup routine it could do a 'master' password for all parts in scenario (2).

My main questions are:

Given a single core cpu and the encryption and running a virtual sometimes, is using an LVM a more intensive workload and more so for the hard disk i/o compared to ordinary encrypted partitions?

Backup strategies, are they simpler or more complex?
If the LVM is one whole thing, for my setup maybe 80Gb, is there a suitable tool to get it all as-is or bzipped onto an ext hdd, in fact is LVM understood by the Linux backup/imaging tools?

What about individual parts inside the LVM, could I use a boot-cd, mount the LVM (decrypt as required) and tar up the various parts?

Having my maintenance outside the LVM might be better for that last given a boot-cd could just do the maintenance and then it, being the same distro, would more easily manage the LVM, yeah?

I've looked over some LVM docs and they don't quite address what I've asked above, so it's people's real-world experiences I'm seeking.

thanks

i use the auto encrypted lvm when i install Debian and split the main 4 partition types it recommends. it runs the same. i have a 3.0 ghz amd 64 4 gigs ram and 1tn hdd ive noticed no lag if that is what you mean by more intensive. its just when i run fdisk -l in term i get errors saying my partion layout isn't correct yeah its funky.

hi, well the pc's likely to be ordinary 2Ghz 1G ram. Certainly when running the virtual I know the cpu will be worked more as there's the "layer" aspect with the encryption, filesystem, LVM, virtual, filesystem.

I'm relatively ok with hdd basics using tools to look directly at them and making sure to copy all the Grub bits somewhere in case a new install trashes them, so I know about how the head will whizz about over the various normal partitions as it needs to get access to files on them.

I'm at the point of not knowing enough where the LVM enters the picture and if it's the same with multi-parts inside the LVM, That is, there's no extra intensive whizzing about or is there, so affecting hdd wear?