Alan McKinnon wrote:
On Saturday 26 March 2011 15:06:31 Elaine C. Sharpe wrote:
Just because something works for most people, doesn't mean it will for
everyone either. If you lose data, it doesn't matter. LVM just adds
one more layer of something to go wrong. Me, I don't need the extra
risk of having a system that doesn't boot and a loss of data. I'm sure
there are a lot of people that see it the way I do too. They just
don't
need the extra risk.
Using the least number of layers of abstraction you can get away with is
a perfectly valid criteria. What I was pointing out was that informal
polls of users with a sad story to tell is not a very effective way to
conduct research. People say all kinds of things that just aren't true.
There's an elephant in this room. The number of actual layers is greater than
just LVM plus FS. It's whatever the BIOS (or a reasonable substitute is
doing), plus the drive firmware, kernel driver(s) - there's more than one of
those - plus any RAID in use (hardware or software) and finally the file
system.
That's a lot of layers, a lot of code, a lot of opportunity for people to
reveal the extent of their lack of knowledge. I've often heard it said that
code like ZFS and brtfs eliminates several of these layers therefore it's
technically a better option. That may be true, but let me just point out that
whatever LVM+fs+other_stuff is doing as separate chunks of code also gets done
by ZFS etc. You just don't see it, and just because it's abstracted away
doesn't mean it's not there.
I'll add this. Alan if I recall correctly runs a lot of systems. He
has a boatload of experience using all sorts of software/hardware. Me,
I don't. For the longest, I had one system and that was it. If I
upgrade my kernel, LVM, or some package that LVM depends on and I can't
boot, I'm screwed. If I can't boot, I can't google anything to find out
how to fix it. I also don't know enough about LVM to fix it myself.
Since there is so many layers of things that can already go wrong on a
system, adding one more layer that can be complicated only makes a
problem grow.
I'm sure Alan and many others could go out and buy or build a new system
and put LVM on it and fix about any problem that comes along. Thing is,
there are others that can't. Add to this that when I was thinking about
using it, I read where a lot of people, for whatever reason, couldn't
get it back working again and lost data. For me, I don't care if it was
LVM itself, the kernel or some combination of other things, if I can't
boot or lose data, the result is the same. I can fix a kernel problem,
a broken package but if LVM fails, I'm stuck.
That said, I now have a second rig. I may at some point use LVM because
I can always go to the other room and use my old rig to get help. I
already have a 750Gb drive that is about full of pictures, I got a
camera and get a little happy at times, and videos I have downloaded,
everything from TV series to stuff off youtube. I may buy another large
drive and use LVM or something to give me more room since I really don't
want to have to break up my filing system across two separate drives. I
won't consider putting the booting part of my OS on LVM tho.
Of course, I did see a 3Tb drive on sale the other day at newegg. o_O
That would last a while. ;-)
Dale
:-) :-)
