[Novalug] Device naming.
Bryan J. Smith
b.j.smith at ieee.org
Mon Mar 15 22:47:45 EDT 2010
The Red Hat LVM Guide is 127 pages in PDF format. There are also
support documentation on how DeviceMapper (a native facility in kernel
2.6 that is always used -- even for Legacy BIOS/DOS disk labels) and
other documentation. LVM (and Cluster LVM) is utilized in many enterprises
for much of the past decade.
As far as "experimentation," you do understand there are more than one
partition table format, correct? And that different platforms don't use the
same, correct? This isn't "experimentation." You mentioned you are going
to be repartitioning a new drive. I merely said you don't have to pre-
determine sizes if you use LVM. You can slice off any size and always
increase it (and decrease it in the case of Ext2/Ext3) whenever you want.
Without taking down the system. ;)
As far as "if the damn thing works," Legacy BIOS/DOS disk labels have
many limitations. In fact, they are being replaced by the GPT disk label
to overcome the 2TiB (2.2TB) limitations. In fact, the legacy BIOS/DOS
disk labels have regularly been a constant source of limitations --
512MiB (528MB), 2GiB (2.1GB), 8GiB (8.4GB), 128GiB (137GB), etc...
In fact, DOS 7 (Windows 95/98/Me) is incapable of supporting more than
As far as "no free distributed file systems," have you used Red Hat GFS?
GFS2 is in the upstream kernel and in various, completely free distros now.
I have no idea what you mean by your user ID field in your file descriptors.
Do you mean you need to copy your password file, setup LDAP, or something
else? I'm wondering what that has to do with the fact that LVM volumes
move between systems and re-present themselves with the same UUID
and LABELs as on the original system? Device names don't matter at all.
It's okay not to want to use LVM and other features. That's your choice.
Just don't blame Linux for that, and call everyone else what you normally do
when we try to explain what you ask the hows and whys.
And yes, NT has a "label" command. It's part of the "diskpart" utility:
If you've done automated Windows installs in the Pre-installation Environment
(PE), you should be familiar with diskpart. You can use it at the command line
in NT's CMD.EXE or other shell, it works the same. You can even define the
mount point (anchor) for a volume instead of a drive letter.
"There is no meaningful difference between the systems except
with drive letters it is easier to put a file on a specific disk."
And "easier" is what you define. Under Windows, you can set drive letters,
although they aren't remembered between systems. Under Linux, you can label
it and have it come up as the exact same name -- /media/(label) or, via
LVM, /dev/(vg)/(lvs). That's with_out_ even messing with udev. This is where
"you know what you know" and that's the world you live in.
The offer still stands. There seems to be some interest on a LVM presentation,
and I'm more than willing to cover udev, LVM and related device and volume
management, so I might have a formal presentation sometime. And I will be
driving from Glen Burnie. ;)
As far as "star chambered courts," I honestly think you don't realize how much
of Linux is developed by people who have no commercial affiliation and grew up
with far less than you did. It's called a meritocracy for a reason, which is how
most projects work. It is a repeat inconsideration by yourself to make such
statements -- a community that works together, not complains "at" each other
without lifting a finger.
Again, I will point you the LVM Administration Guide, try Section 1.2:
But it's increasingly obvious that you don't read anything anyone sends, and you
immediately dismiss it. There is also the LVM HOWTO and other documentation
out there that covers many things in detail.
I think the rest speaks for itself ...
- You don't know what /media is (and all the automation)
- You have no idea what security is (let alone don't realize how this improves security)
- You don't use Linux as a desktop OS at all (which is where automation helps)
You are honestly at least 7-10 years out-of-date with Linux developments, security,
automation and desktop features. But please do continue with to tell us how Linux
from the 1990's sucks, etc...
Until then, all I can do is invite you to understand these concepts -- which in many
cases -- are _not_ related to just Linux. ;)
----- Original Message ----
From: Alan Grimes <agrimes at speakeasy.net>
When someone writes a textbook on the subject, I'll read it and maybe
even start using the feature.
Which of my own running systems do you propose I sacrifice to such
experimentation? I do have some space on my data drive but then I'd need
a mighty powerful motivation to place it in any jepordy as you seem to
be proposing. My server machine is expendable but it doesn't have any
If the rule "If the damn thing works; don't #### with it" applies to
anything, it applies to partition tables.
I don't know what you're talking about... There are no free distributed
file systems, they cost either $1,000 or a stroke (brought on by the
mental exertion required). The difference between linux and the theory
of relativity is that you can master the theory of relativity, and you
have a good reason to do so.
I was planning to cart my data drive over to my new computer but the
user ID field in my file destriptors will #### that plan up nice and royal.
If I had the option of hiring an admin to do this work, then I wouldn't
care, but oops, I'm the admin, and I'm a lazy bastard, and I want my
same old configuration to continue to operate perpetually.
Have you ever tried the command "label" on a DOS or windows machine?
So what? There is no meaningful difference between the systems except
with drive letters it is easier to put a file on a specific disk. It
therefore becomes much easier to predict what a hardware change will do
to your data.
The meetings are 20 miles away from where I live, it's much too long of
a trek that early on a Saturday...
My only portable system is an eee pc, I keep the stock xanderos on it
because it works much better than anything I could install or configure
The market has been railroaded, there's no "evolutionary optimum" about
it. People in star-chamber courts proclaim edicts about how block
devices should be organized and the changes are made years before I'm
even aware of it and the actual proceedings are never published, and the
solution is never explained until years after it is obsolete.
My system was built nearly 7 years ago. The primary motivation for me
changing my /etc fstab is me trying to mount my optical drive, finding
the drive assignment has changed, having to edit my entry for
/mnt/cdrom, grumble, and then carry on... I don't have much use for it,
the kde4 penguins decided to break k3b so it looks like I won't be able
to burn CDs or DVDs anymore. =(
Are these concepts documented outside out-of-print and expensive HP
manuals? ( I need diagrams, code samples, benchmarks, and lots and lots
Again, I have far far too little information about how such a stack
works and what the hazards are. I would not even dream of resizing one
of my working partitions without months of consideration and a dire need.
I had no idea that /media was for anything whatsoever....
I think my eeepc has a lot of automation on it and it probably does
/media the SD cards I sometimes use with it. But then who knows what
asus has done to the thing...
On the rare occasion I do need to mount a guest filesystem, I simply use
something under /mnt and do it manually. It is a major security risk to
allow anyone but root to mount filesystems.
I liked minix alot, even wanted to buy the T-shirt, then I read
process.c and I can't forgive the developers for that monstrosity of
code. =( Minix got a thousand things exactly right but then they blew it
all when they wrote process.c; the entire operating system is
irredemable for only that reason and no other.
Linux will never be good, as a desktop OS. I'm resigned to that. I'm
only against it getting any worse. =(
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