Messages in this thread | | | Date | Tue, 30 Sep 1997 17:57:10 -0400 | From | "Theodore Y. Ts'o" <> | Subject | Re: Logical Volume Manager |
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From: Heinz Mauelshagen <mauelsha@ez-darmstadt.telekom.de> Date: Tue, 30 Sep 1997 17:37:16 METDST
Because logical volumes (LVs) can be resized at runtime i need a filesystem (FS) feature which enables ext2 to be extended/reduced while its mounted too. This could be an extension to tunefs or a separate FS administration tool.
You know what you ask.....
Resizing an ext2 filesystem is difficult. Reducing is obviously much harder, but even in the extending cases, in some cases you will need to move disk blocks around to make space for the larger block group descriptors.
The hardest thing to deal with, and it's an issue even with Miguel's patches, is what to do when you want to remove a physical disk located in the middle of an ext2 filesystem. Not only do you have to worry about moving data blocks off, but over the long term, there are (disk) address fragmentation issues that come up as well.
It's possible, although nontrivial, to do this off-line. Doing this while the filesystem is mounted, and possibly active, is much, much harder.
- Ted
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