Rounding problem with GParted

It seems that the logical partition /dev/sda5 is aligned to Mib but the other 3 logical partitions /dev/sda6, /dev/sda7 and /dev/sda8 are aligned to cylinder (the start sectors are divisible by 63). I can't know how these partitions were created (I guess they were created perhaps by various tools and in several phases over the years).
This means that you have to align all these 3 partitions by MiB. I would advice to proceed one by one, so that you can check the result after each step. This takes longer but it is safer.
Furthermore, I don't stop to advice backup of any important files before doing any work on the partition table, as there are many factors that could go wrong (especially hardware or power failures).

It is safer to use the latest GParted version in order to avoid older bugs. I'm not sure how large gaps it leaves.
You can try, keeping the "Align to MiB" setting. This will perform a move & resize operation to recreate the partition according the selected settings. If there is any gap larger than 2048 sectors, you can try to move or expand the partition to the left.
It is better to respect the minimum suggested by Gparted, as there is some space needed for the "partition boot records".
However, it is better to know what all these partitions are for. This isn't a typical windows partitioning. If they are related to any system function like system recovery, this function could not work.

Hello, thank you for the answer. Too bad this bug is around since 2010 !

If I may offer a suggestion which should help solving the problem, and also address the demand in the above mentioned bug report of "selectable unit (Sector(512), Sector, Kilobyte, Megabyte, Gigabyte, Cylinder)", that would be to decorrelate input from output.

Basically, inside the Dialog:
- maintain a set of input parameters for resize/move in sectors unit only, and manipulate all in sectors intenally,
- initiate with current values when opening the Dialog, and save them as start values in a second structure
- display current input values in the modification boxes according to "alignment" chosen, and when a new alignment is chosen, convert the box contents as needed
- display besides input section an output section (not modifiable) containing the resulting current values in sectors, and show in bold for example what has changed compared to start values
- you can even display a kind of warning on the start sector side when it is modified, in addition to the pop up appearing when Ok is pressed, to highlight such a modification.
- any time something is changed on input side (a value entered or up/down arrows pressed or units changed), recalculate current sectors value according to alignment and refresh the output display
- add a button to Reset all back to initial values
- and a Cancel and Ok buttons of course

When Ok is pressed, you are able to tell if the start sector of the partition was changed or not.
And with the "bold" (or whatever else) feature, the user is conscious when the start sector has changed.

Sorry if this is not very clear. If you want that I take a look to express things better, could you point me at the module(s) handling that part in the code as I am not familiar with it ? I'll try to express things better in code, and post my suggestion in the bug report, if you agree.

(note: to my problem, since my purpose is to align partitions on 1 MB boundaries , I will have to do the 2 steps thing for now. I was suspecting it, thanks for the confirmation).

Best regards, Erwin9.

Ok, I do not have Linux right now on my system so won't be able to compile / verify anything.
I'll wait to get my SSD to add one more partition and install Linux .. (will just have to be careful that Grub2 does not mess up my GRUB4DOS ..), and then I'll take a look at whether I can help or not.

Meanwhile, I'll try to wander in the code to see if I can easily find my way and logics surrounding the Dialog (I am not familiar with GTK).

Now, on what appears to be the same root problem, I found one more symptom / bug if I may ..

You remember my 2 partitions above:

Device     Boot     Start       End   Sectors  Size Id Type
/dev/sda6       205632063 254935484  49303422 23.5G  7 HPFS/NTFS/exFAT
/dev/sda7       254935548 304094384  49158837 23.5G  7 HPFS/NTFS/exFAT

So to align sda6 in 2 steps, I decided to add 2-3 MiB at start.

When opening the Resize/Move Dialog, it was showing the following initial values:

Free space preceding (MiB): 1
New size (MiB):             24074
Free space following (MiB): 0

I pressed 3 times the up arrow on "Free space preceding" to get:

Free space preceding (MiB): 4
New size (MiB):             24071
Free space following (MiB): 0

Pressed ok, and got the idea to look at the new information for the sda6 partition.

New start moved by +5569 sectors to get to 205 637 632.
Old start was 205 632 063 as you can read above, which is 575 away from the immediate lower 2048 boundary (at 205631488), so that looks good

575 + 5569 = 6144 = 3 * 2048

However,  the end moved also.
New value was 254937087, which is 1603 sectors more "to the right".
I can understand why .. 254937088 is the next 2048 boundary (1 MiB), so this value got aligned also.

But .. look at the start point of partition sda7 above: this new end for sda6 is overlapping with the start of sda 7 !! 

Happy that I looked at it ... it would have failed !
I had to increase the "Free space following" to a value like 2 or 3 to get proper values.

And now that I say it, I remember I had gotten the same problem when aligning my last partition (sda8, see above post) previously.
It had failed, and when looking at the details log, no wonder, its end was getting aligned on a value which was beyond the end of the disk .. same problem obviously.
I believe I got around it at the time deleting and recreating the partition. Indeed, since it is my Win7 SWAP partition, there is no static data on it.

Hope this helps .. I'll come back hopefully when I get my SSD and have installed Linux on a new partition to start looking at code.

Meanwhile, let me know if I can be of any use, cheers