Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I bought a new HP Pavilion DV7-6199US. In the past on all my computers I have always used Ubuntu primarily and I keep a version of Windows in case I need something that I can't do easily in Linux. I have always just re-sized the main Windows partition to leave enough space for Linux to run with no problems. I would leave the remaining space for Linux on the disk with no partition or anything, just unused space. Then I would run Ubuntu's installer and tell it to use the unused space. Never a problem, Ubuntu would create partitions there however it wanted to.

This time I did all this, but when I resized the partition in Windows the remaining space was labelled unusable by Linux and Windows. So I said OK no problem I booted Ubuntu 11.10 from USB and I just deleted the whole Windows partition and created a 492 GB partition to install Windows on again.

After doing this the Disk Management Utility in Ubuntu said the following error: "Warning: The partition is misaligned by 3072 bytes. This may result in very poor performance. Repartitioning is suggested." Do I keep going? Is this just a screwy error that I can ignore? I can't handle bad performance issues.

I'm not very experienced with the command line so GUI-only unless you can really be patient with me, please.

share|improve this question
Please give the output of: sudo fdisk -l; sudo parted -l – medigeek Feb 13 '12 at 14:59

The older hard drives used smaller 512-byte sectors; recently newer drives use larger sectors, usually 4096 bytes.

Software, however, is still sees the disk in 512-byte "logical" sectors, although it often reads the data in 4K chunks

When creating a partition, it is important to align the beginning of the partition with the beginning of the large physical sector, otherwise each read will require reading 2 physical sectors, which will affect performance.

As you can see, your partition starts from logical sector #3 (#1 and #2 take 512*2=1024 bytes), so to fix the problem you need to move the start of the partition by 3072 (4096-1024) bytes.

Newer versions of gparted are aware of this - just boot from Ubuntu LiveCD and create a new partition selecting the default alignment option (which is "align to 1 MB", which is optimal even for larger sector size, such as in SSDs).

If you already installed OS and do not want to re-create partitions, you could move the start of the partitions to align properly, but that would involve some pen-and-paper calculations. Also, you'll need to reinstall the bootloader if you moved Ubuntu partition.

share|improve this answer
Wow I am going to get on that right now. Thank You Sergey for taking the time to explain this in a way even a new guy like me can understand. God Bless. – Druckin Feb 13 '12 at 22:21

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.