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Is it possible to change a hard drive's file allocation unit size without formatting or at least not lose files?

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up vote 4 down vote accepted

There are third party partition managers that allow you to change the cluster size without reformatting. One example is the MiniTool Partition Wizard (all non-free versions):


Be aware that all changes to a partition might corrupt the data. Backing up the important files is always a good idea.

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Acronis Disk Director only changes cluster size for the free space on the volume: – haimg Jun 5 '12 at 17:20
@haimg: Thanks for the heads up. – Dennis Jun 5 '12 at 17:24
And MiniTool Partition Wizard can only change the cluster size without formatting of dynamic disks, not basic disks. – Synetech Jun 5 '12 at 17:45
I don't think GParted GUI can't do it either; I just booted into it and there is no option to select the allocation unit size (or cluster size) when changing the partition. I read elsewhere that it uses 4096. – David Murdoch Apr 7 '15 at 19:50
@DavidMurdoch: I based my answer on an eHow article, but GParted doesn't even let you choose the cluster size when creating a partition. – Dennis Apr 7 '15 at 22:06

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