On 5/19/21 9:20 AM, Leslie Rhorer wrote:
On 5/18/2021 1:31 PM, Reindl Harald wrote:
[trim/]
leave some margin and padding around the used space solves that
problem entirely and i still need to hear a single valid reason for
using unpartitioned drives in a RAID
I can give you about a dozen. We will start with this:
1. Partitioning is not necessary. Doing something that is not necessary
is not usually worthwhile.
1a: sure. 1b: I can think of many things that aren't *necessary* but
are certainly worthwhile. I can even throw a few out there, like
personal hygiene, healthy diets, exercise. In this context, I would
list drive smart monitoring, weekly scrubs, and sysadmins with a clue.
2. Partitioning offers no advantages. Doing something unnecessary is
questionable. Doing something that has no purpose at all is downright
foolish.
Who says it has no purpose. Its purpose is to segment a device into
regions with associated metadata.
3. Partitioning introduces an additional layer of activity. This makes
it both more complex and more wasteful of resources. And yes, before
you bring it up, the additional complexity and resource infringement are
quite small. They are not zero, however, and they are in essence
continuous. Every little bit counts.
Hmm. A sector offset and limit check, buried deep in the kernel's
common code. I dare you to measure the incremental impact.
4. There is no guarantee the partitioning that works today will work
tomorrow. It should, of course, and it probably will, but why take a
risk when there is absolutely no gain whatsoever?
You assert "no gain", but you provide no support for your assertion.
5. It is additional work that ultimately yields no positive result
whatsoever. Admittedly, partitioning one disk is not a lot of work.
Partitioning 50 disks is another matter. Partitioning 500 disks...
You assert "no positive result whatsoever". Sounds like #4. With
similar lack of support. Fluffing up your list, much?
6. Partitioning has an intent. That intent is of no relevance
whatsoever on a device whose content is singular in scope. Are you
suggesting we should also partition tapes? Ralph Waldo Emerson had
something important to say about repeatedly doing things simply because
they have been done before and elsewhere.
No relevance? Metadata can be rather useful when operating systems
encounter what looks like an empty disk. Metadata that says "not
empty!" Especially valuable when metadata is *recognized* by all
operating systems. You know, like, a *standard*. While MDraid places
metadata on the devices it uses, only Linux *recognizes* it.
7. There is no downside to forfeiting the partition table. Not needing
to do something is an extremely good reason for not doing it. This is
of course a corollary to point #1.
Just more fluff.
Microsoft and a number of NAS products are known to corrupt drives with
no partition table. I vaguely recall hardware raid doing it, too.
That's a damn good reason to add a tiny (measurable?) amount of overhead.
And dude, making a single partition on a disk can be /scripted/. Might
want to learn about that, if the pain of the driving fdisk/gdisk
occasionally is too much for your delicate fingers.
Phil
