1 Topic by ronbaby (edited by gedakc 2016-05-04 21:46:32)

  • ronbaby
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Topic: [closed] New partition size & alignment problems/issues

Sorry for the formatting of the following message.  This *&^%%$#@ systems decided to uncerimoniously log me out during the brief time that I was composing the following message, and so I had to resort to cut-and-paste to get it back again without having to retype the whole bloody thing.

So I guess that in enhancement request #1:  Could SOMEBODY PLEASE get this dumb system from logging me out while I still busy typing a message?  I mean geezzzz.

Sigh.  Now on to my REAL message...

Before posting here, I downloaded 0.14.1-6 (amd64) to try to make sure that I'm
not asking about things that have already been fixed.

Maybe there's something that I'm not aware of, of that 'm not understanding, and
if so I hope and trust that others here will enlighten me.  Otherwise, please d
o consider my comments herein to be feature requests.

The following questions relate to the "Create New Partition" dialog box.

What is the reason that gparted insists on preceding the first partition with at
least 1 MiB ?  What is the reason that it insists on preceding it with anything
?  Could this limitation of gparted be removed?  If so, please consider this a r
equest to remove this (apparently artificial and pointless) limitation.  I don't
believe that there is any truly _compelling_ reason for it, and the tool would
be more flexible without it.

Now, on another topic...

When alignment is set to "cylinder", why is it that -none- of the other user-sel
ectable parameters on/in this dialog box follow suit?  I mean seriously, if I, t
he user, am asking for cylinder alignment, then it seems to me that I should be
able to ask for some number of CYLINDERS to precede the partition I am creating,
and also, it seems to me that I should be able to request a new partition whose
size is equal to some number of CYLINDERS.  (Am I the only one for whom these t
hings seem obvious?)

Lastly, why are there only three choices offered for new partition alignment "Mi
B" or "cylinder" or "None"?  This limitation seems to me pointless and unnecessa
ry.  Why now allow the user to specify any bloody kind of alignment he/she wants
?  It wouldn't be particularly hard to do, and would make gparted maximally flex
ible.


P.S.  I've used gparted in the past many times.  Just now I have been using it b
ecause the partitioning capabilities of FreeBSD which are available at OS instal
l time are (a) very limited and also (b) archaic to the point of being effective
ly brain dead.

For reasons I don't pretend to understand, FreeBSD (still) wants to align things
on "cylinder" (63 sector) boundaries.  But my shiny new hard drive wants everyt
hing aligned on 4KiB boundaries.  I was trying my best to accommodate both, usin
g gparted.  So I wanted to make a partition starting at sector 504 (least common
multiple of 63 and 8), *and* also make a partition that was some multiple of 50
4 sectors in size.  But of course, gparted wouldn't cooperate.  Like not at all.

I think that should be fixed.


P.P.S.  Another feature request relating to "Create new Partition".  As of now,
gparted cannot create and format partitions containing BSD UFS filesystems.  OK
fine.  But you should at least allow me, the user, to *create* such a partition,
even if gparted can't quite do "newfs" on it.

What I mean to say is:  (feature request)  Allow the user to specify, explicitly
, the numeric partition type code, e.g. if and when the file system type selecte
d is "unormatted".

2 Reply by class413

  • class413
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Re: [closed] New partition size & alignment problems/issues

A general comment from my part: GParted performs various tasks using various free-open source tools. These tools usually work from the command line with parameters that allow to adjust many details. GParted provides a graphical front end for these tools. However, putting every command line option in the menu would be rather confusing for most users. Some "advanced" options and possibilities were left out, trying to keep safer options. As an example, I note the options to overcome bad sectors. Applying some operations on a drive with bad sectors could make things worse and further corrupt data. It is possible to manually run the specific tools. However, this is not the "typical use" of a resizing tool.


GParted provides 3 alignment options in manipulating partitions: MiB (mostly for newer systems and hardware), cylinder (mostly for older systems and hardware) and none (this allows, say, to resize a partition from the end keeping the start sector as is, and avoid boot problems).
The sector 63 (cylinder alignment) is an old restriction by the BIOS and many older operating systems.
The MiB alignment is needed in practice be the newest hardware (SSD, 4KiB/physical sector hard drives). Of course, a 4KiB alignment would be good for latest rotating drives (sector 64 would be good too), but there is need for the GPT information too, so the MiB was adopted by the newer operating systems.
Creating partitions from any sector number would make the software much more complicated, with no practical need in most of the cases (I mean by this that such advanced features could easily confuse the average or inexperienced user. Experienced users can use sometimes the command line with no fear. Partitioning after all isn't an everyday's task).

Concerning the FreeBSD issue, is this a partitioning tool problem or some kernel issue?
You could perhaps try parted or fdisk from the command line to create the partition.

Of course, every feature request is welcome.

*** It is highly recommended to backup any important files before doing resize/move operations. ***

3 Reply by gedakc

  • gedakc
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Re: [closed] New partition size & alignment problems/issues

Further to the comments by class413, GParted uses the GUI to guide placement of partitions and the "Align to" selection will decide the actual sectors for the start and end of the partition.

When the GUI indicates it is reserving 1 MiB in front of a partition, this is to ensure that unallocated space is reserved in front of the partition for:
a)  the partition table or Master Boot Rectord (MBR) which is stored at the front of the drive, or
b)  The Extended Boot Record (EBR) which is required in front of each logical partition.

With Cylinder alignment, the first partition will have 63 (512 byte) sectors reserved at the front of the drive.  With MiB alignment, the first partition will have 2048 (512 byte) sectors reserved at the front of the drive.

As class413 points out, if you need non-standard sector placement that does not match either legacy cylinder alignment, or modern operating system MiB alignment, then you might investigate using command line tools such as fdisk or parted.

Feature requests are welcome.  In fact an enhancement request to be able to specify different units has already been created.
See Bug 622150 - Support for data entry and display of logical blocks (sectors)

4 Reply by ronbaby

  • ronbaby
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Re: [closed] New partition size & alignment problems/issues

It appears that I was not clear in my earlier comments so let me try again.

When one selects the "align to cylinders" option in the GUI, the amount of free space preceding is still labeled as being denominated in MiBs.  This is just clearly wrong, and should be fixed.  It makes no sense.  In the case where one is aligning to cylinder boundaries, obviously, one expects and requires that the amount of space preceding the partition being created should be denominated in cylinders... notin MiBs.

Likewise, when one selects the "align to cylinders" option in the GUI, the number of units to allocate within the partition being created is still denominated in MiBs.  This is also wrong, and should also be fixed.

I suppose that I can understand if there is no desire to implement, in the GUI, a feature which would allow totally arbitrary alignment, however these other aspects of the GUI are just plain wrong.

I supposed that I should file formal bug reports on each of these issues.

5 Reply by gedakc

  • gedakc
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Re: [closed] New partition size & alignment problems/issues

Bug 695594 - Alignment to cylinder boundaries is mis-handled in the GUI