14 messages in org.freebsd.freebsd-questionsWhy is 'disklabel'ng a new drive so d...| From | Sent On | Attachments |
|---|---|---|
| Marc G. Fournier | Mar 28, 2007 8:26 pm | |
| Kris Kennaway | Mar 28, 2007 8:41 pm | |
| Marc G. Fournier | Mar 28, 2007 8:48 pm | |
| ill...@gmail.com | Mar 28, 2007 9:04 pm | |
| Jerry McAllister | Mar 28, 2007 9:20 pm | |
| Jerry McAllister | Mar 28, 2007 9:24 pm | |
| Jerry McAllister | Mar 28, 2007 9:29 pm | |
| RW | Mar 28, 2007 9:48 pm | |
| Jerry McAllister | Mar 28, 2007 10:13 pm | |
| Antony Mawer | Mar 29, 2007 10:07 pm | |
| Jerry McAllister | Mar 29, 2007 11:22 pm | |
| Antony Mawer | Mar 29, 2007 11:55 pm | |
| Jerry McAllister | Mar 30, 2007 3:09 pm | |
| Daniel Eriksson | Mar 31, 2007 9:35 am |
| Subject: | Why is 'disklabel'ng a new drive so difficult? | |
|---|---|---|
| From: | Jerry McAllister (jerr...@msu.edu) | |
| Date: | Mar 29, 2007 11:22:56 pm | |
| List: | org.freebsd.freebsd-questions | |
On Fri, Mar 30, 2007 at 08:07:23AM +1000, Antony Mawer wrote:
On 29/03/2007 6:41 AM, Kris Kennaway wrote:
On Wed, Mar 28, 2007 at 05:26:49PM -0300, Marc G. Fournier wrote:
Just bought a new WD SATA drive: WDC WD5000YS-01MPB1 09.02E09
Tried to disklabel it, and it gives me all kinds of warnings when I look at it after running the disklabel:
ganymede# bsdlabel -w ad4s1 auto ganymede# bsdlabel ad4s1c # /dev/ad4s1c: 8 partitions: # size offset fstype [fsize bsize bps/cpg] a: 976767986 79 unused 0 0 c: 976768002 63 unused 0 0 # "raw" part, don't edit partition a: partition extends past end of unit partition c: partition extends past end of unit bsdlabel: partition c doesn't start at 0! bsdlabel: An incorrect partition c may cause problems for standard system utilities
Even if I try to use /stand/sysinstall to do the fdisk, the end result has 'issues' ...
So, what is the generally accepted method of label'ng a new drive? :(
I learned a useful trick the other day: you can use abbreviations like "1g", also '*' to mean "automatically calculate". See the manpage.
This timely thread came as I was experimenting with disklabel, and I noticed in the man page it says this:
offset The offset of the start of the partition from the beginning of the drive in sectors, or * to have bsdlabel calculate the correct offset to use (the end of the previous partition plus one, ignor- ing partition `c'. For partition `c', * will be interpreted as an offset of 0. The first partition should start at offset 16, because the first 16 sectors are reserved for metadata.
When I tried using "16" as the offset for my 'a' partition, I could no longer user "*" on my last partition to make it auto-size... disklabel then sized the partition so it went past the end of the disk. Presumably it's not taking into account the starting offset when it does this (gm0 is a 3gb gmirror device, with a single slice created on it using fdisk):
$ bsdlabel -R /dev/mirror/gm0s1 /dev/stdin 8 partitions: a: 2097152 16 4.2BSD b: 102400 * swap c: * 0 unused d: 102400 * 4.2BSD e: * * 4.2BSD partition e: partition extends past end of unit
However if I change the 'a' partition offset to 'e', it works:
$ bsdlabel -R /dev/mirror/gm0s1 /dev/stdin 8 partitions: a: 2097152 0 4.2BSD b: 102400 * swap c: * 0 unused d: 102400 * 4.2BSD e: * * 4.2BSD $ disklabel /dev/mirror/gm0s1 # /dev/mirror/gm0s1: 8 partitions: # size offset fstype [fsize bsize bps/cpg] a: 2097152 0 4.2BSD 0 0 0 b: 102400 2097152 swap c: 6281352 0 unused 0 0 # "raw" d: 102400 2199552 4.2BSD 0 0 0 e: 3979400 2301952 4.2BSD 0 0 0
Is it important to use 16 as the offset still, or is this a historical piece of information that is no longer relevant? Or is this is a bug in disklabel that should be fixed?
As I indicated in another post in this thread, it appears to be vestigial. I have never used it for a bsdlabel(disklabel) being done on a slice - since 1998.
There seems to be a lot of left over stuff in the documentation and man pages for fdisk and bsdlabel (and disk formatting, partitioning and booting in general). Someone made a pass at cleaning them up about 6 years ago and that helped, but it could stand to be done some more. If I felt knowledgeable enough, I would take a whack at it. But there are too many holes (not wholes) in my knowledge. I would guess from posts in the list that a lot of people are in that position - knowing a bunch of it, but not quite enough to be authoratative about it.
I have written several long replies to questions on this list that could be the basis for FAQs or HowTo-s, but they still leave a lot of things out and generalize or slide over lots of other things for the sake of convenience, avoiding confusing a newbie and/or not being sure about all the details.
////jerry
--Antony
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