Many methods are available out there to extend a partition when low disk space problems happen and the Extend Volume grayed out in Disk Management, we’ll list 4 of them.
The common method of extending a partition is to borrow free space from other partition, a partition on the same disk with plenty of used space, it’s called and displayed as Free Space in Disk Management when that space is created on a logical hard drive, and it will be shown as Unallocated Space when it’s stayed on a primary partition. No matter where it’s from or what name it’s called, we can use such space to extend a volume that is in low disk space warning
In Disk Management, the Extend Volume is responsible for such kind of operations, but it won’t be active unless we create continuous unallocated space right next to the partition we’d like to extend (not left to, exactly on the right side), most of the disk-map in Disk Management won’t suite such conditions, so we can try a third-party program to do so
Partition Expert is the software we’ll be using, a portable disk managing program, we can directly run it without installing it to the system
Before extending a volume, let’s find out if we have unallocated space (free space) on the same disk, if there’s no, we can create it first
When it comes to creating unallocated space, Disk Management actually does a good job, the Shrink Volume function is capable of performing such operation, but the unallocated space it creates cannot be used for extending another volume, since the position of that space is not next to any partition except the one it shrank from, so unallocated space created from the Shrink Volume function is not the solution here unless we can shrink a partition from the head section
In Partition Expert, we can shrink both the head and end section just by doing so when we have a disk-map like this:
Tip: it’s also to drag the handle on the right side to shrink this volume, but don’t forget to drag the entire E Drive (hover on the middle of the par, drag it when the cursor becomes a cross arrow) to the end before clicking OK
Now we have a disk-map like this:
If we open disk management now, the Extend Volume option on D Drive is activated, we can extend D if it’s also out of space. The same option on C Drive is still greyed out, try the followings then:
Now Unallocated space is right next to C Drive, open the Disk Management tool and the Extend Volume in right-click menu option is now activated, go ahead and click on it to follow the Extend Volume Wizard or use Partition Expert to complete the extending operation like this:
Now we have a disk map like this:
Although the borrow free space is simply to follow, it looks complicated, and it takes that much paragraph to make itself clear, most of the users may feel frustrated on see the long description, but it’s not troublesome, all those steps can be done within few clicks. Anyway, we do have a simpler solution (Partition Expert tutorial page explained how to use this tool in detail but simple steps)
Partition Extender: An easier way of extending a partition
Like the name indicates, this small utility focus on solving low disk space problem and makes extending partition easier, and it’s also a portable program, it doesn’t require unallocated space in the right position to extend a volume, if you have free space on any of the partition on the same disk, any other partition in low disk space can be extended.
So take the same example, the same disk-map above (C D E), in Partition Extender we can do the followings:
Why do we have to click D Drive first? what’s behind the steps?
Actually, we don’t have to click D Drive and extend it first, we do so when D Drive, too, has not enough free space, if you got much free space on D Drive, you can directly click C Drive and extend it.
Use Partition Extender together with Disk Management (although you don’t have to):
diskmgmt.mscin the run box and press enter to open Disk Management
In Partition Extender, we can directly extend C Drive on disk-map like this:
the disk-map which Disk Management can’t extend C, we checked out the Extend Volume is still greyed out. So next time when you run Disk Management try to extend a volume but that option is disabled, you can try Partition Extender, to fix this problem with ease
Method 1 shows us how to extend a volume with free space from other partition, we can either create unallocated space or directly extend the small volume, with the help of Partition Expert and Partition Extender, extending a volume without data loss is an easy an safe job
The second method of extending a volume is to merge another volume to it, merged volume will add both free space and all the data from that partition, use the example above, we can merge C and D drive as a new C Drive, everything on D Drive will be stored in the new folder call “D”, so if you have programs installed on that path, you might change the shortcut path from “D:/” to “C:/D/”
And we don’t recommend to store non-system related data on C Drive, we can use this merge function when you’ve created unallocated space in Disk Management but don’t know how to merge it to C Drive, so in Partition Expert, we can do it like this:
This solution also works on the disk-map like:
The theory here is to create an E Drive on unallocated space and merge it into C and extend that drive, an alternative way to extend C Drive, although there’s no need to create a new partition and extend, we can use the Extend Volume function instead to extend C Drive, but if the file system of C Drive is FAT32, that extend option will still be grayed out, and that’s the time the Merge Volume helps
The Merge Volume function works on partitions that adjacent to each other, but if there’s unallocated space between them, it will work too, the function would merge both the unallocated space and the partition you chose to the target drive
The previous two methods are using free space on the same disk, but there are situations that the entire disk is out of space, we only have free space available on another disk, how can we extend a volume them?
Well, we can’t, if we’re using a basic disk, unless we convert the disk to dynamic. But we can copy the entire volume to another disk, another disk with larger capacity, check the disk-map below
Currently all the partitions on Disk 0 are out of space, but F Drive on Disk 1 has very much more free space, and this hard drive has a larger size than Disk 0, Extend Volume won’t work on Disk 0 since there’s no unallocated space, Merge Volume will work but makes no sense, no partition is extended, we can make the disk-map like this to get more space for C Drive:
We can move both D Drive and E Drive from Disk 0 to Disk 1, and C Drive uses all the space on Disk 0. Detailed steps are as followed:
Now we have two new drives: G Drive and H Drive on Disk 1, and D, E Drive are still in Disk 0, so we now delete them and change G, H drive letter to D, E.
New disk-map after copied volume:
We’ll remove D, E, and Extend C Drive, steps are the follows:
Now check the disk-map again, we’ll have:
This method is quite helpful for Server users, when Disk 1 is full and C Drive’s free space is taking up by log files, temporary files, we can use the Copy Volume function to move extra data to another disk, say, for example, Disk 2, make C Drive has only system-related files
There are situations that method 3 won’t work, check the disk-map below:
Now C Drive is out of space in Disk 0, no free space on the same disk, so all the methods above won’t work, but Disk 1 has free space on it, much of it, D, E, F are empty drives, nothing in them, now we need a larger C Drive, but don’t want to re-install the operating system, how can we solve this problem.
In Partition Expert, we can migrate the operating system to Disk 1 and delete everything on Disk 0, make it as a data disk, like this:
So how we gonna achieve that? you can check the detailed migrate OS guide, or use the steps below:
After booting into the system, we can delete the old C Drive on Disk 0 and set a new drive letter on it, by doing this, we safely moved the operating system to a new drive and enlarged its size, while the old one set to a data partition
But there’s a problem on this method if Disk 0 is an SSD and Disk 1 is an HDD, is it necessary to migrate? SSD drives boot faster, if the boot speed do matters, then a new and larger SSD will do the job, no need to migrate it to the HDD, but the Migrate OS function in Partition Expert can still be a helper when you migrate OS between SSDs