How To Resize Linux Partitions

This article covers two methods of resizing Linux partitions, with information specific to BootIt BM users. For details on using BootIt NG, please see this article.

Warning: When resizing any partition, there is always some risk of data loss, regardless of which method is used to resize it. It is highly recommended that you have a reliable backup of the partition (such as a partition image) before proceeding with the resize operation.

Note that BootIt BM supports resizing Ext2, Ext3, and Ext4 Linux partitions. For unsupported Linux partition types use one of the methods below.

Method 1: Use the GParted Live CD to resize in one step. This method is appropriate only for BootIt BM users who limit primaries, meaning that the Limit Primaries setting for the drive is checked. GParted is a graphical partitioning utility, and is available on many Linux Live CDs, as well as on many installation CDs that double as Live CDs.  The most commonly used Live CD for this purpose is probably the GParted Live CD, which is a bootable CD containing primarily the GParted program. It can be used to resize Linux partitions in one step from a graphical environment. For more information on how to use GParted, please refer to the GParted documentation.

Caution: GParted will not be appropriate for resizing partitions on systems where BootIt BM is configured to not limit primaries, meaning the Limit Primaries setting for the drive is not checked. This is because when primaries are not limited, all partitions known to BootIt BM may not be in the MBR partition table at any given time. GParted will see any partition not included in the MBR partition table as unpartitioned space, and therefore could overwrite existing partitions that it doesn't know about. This will cause data loss. For this situation, Method 2 described below is recommended.

Method 2:  Use the combination of BootIt BM and the GParted Live CD. This method is appropriate for BootIt BM users who do not limit primaries and is recommended for advanced users only. To allow GParted to resize the Linux partitions on a drive where primary partitions are not limited requires configuring the drive in such a way that GParted won't corrupt any of the existing partitions. Warning: As there is a risk of data loss involved, it is recommended that a backup image of the drive (all partitions) be created prior to resizing the partition(s).

Before proceeding, consider converting the drive to a standard MBR type (or limiting primary partitions). This can be helpful when working with unsupported Linux partition types if resizing is going to happen frequently. By having the drive configured as MBR, resizing can be done at any time using GParted. Note that converting the drive may require deleting or relocating partitions to get the number of primary partitions down to four or less.

The steps required to resize an unsupported Linux partition are as follows:

1. Boot into BootIt BM, enter Partition Work, and resize or slide any existing partitions to make room for the resizing of the unsupported Linux partition. For example, if you have a 20GB ReiserFS partition located just before a 100GB Fat32 partition and you want to resize the ReiserFS partition 10GB larger, the Fat32 partition would need to be resized 10GB smaller and moved down 10GB to place the free space between the two partitions. Depending on the ultimate goal, multiple partitions may need to be manipulated.
   
   
2. Once the required free space is available, click the View MBR button and load the required partitions to the MBR. The partitions to load are the one just prior to the one to be resized, the partition to resize, and the partition just after the one to be resized. For example, if the partition layout resembles the following table and the ReiserFS partition (#4) needs to be resized larger, you would need to load partitions 3, 4, and 5 into the MBR. Doing this will allow GParted to see the partitions surrounding the one being resized and prevent it from overwriting or otherwise corrupting them.

3. With the partitions loaded into the MBR (don't forget to Apply the changes), insert the GParted CD, reboot the computer, and load GParted. Select the partition that needs to be resized and resize it.
   
   Warning: Do not perform any operations on any other partitions or in any unallocated space located outside the surrounding partitions as this can cause serious data loss. In addition, if the partitions and unallocated space displayed by GParted are not as expected, do not continue. Instead, boot back to BootIt BM and correct the problem.
   
   
4. With the resize complete, exit GParted, exit Linux, remove the GParted CD, and boot back into BootIt BM. You may receive a warning that there are partition errors. Proceed to Partition Work and fix any errors (indicated by an 'E' on the partition line). For example, you may need to delete a partition that previously existed in the EMBR and has now been replaced by the resized partition. Verify the partition details displayed are correct.
   
   
5. Update any partition names and boot items as necessary to account for the partitioning changes.