[NTLUG:Discuss] Resizing Linux partitions

[Leroy Tennison]

Robert Citek wrote:
> On 06/15/2007 07:32 PM, Leroy Tennison wrote:
>   
>> No big deal since is was a test partition anyway, just some time 
>> wasted.  However, I am now very curious as to how you are supposed to go 
>> about resizing both ext3 and reiserfs partitions.  Anyone have good 
>> success with this using any non-commercial program?
>>     
>
> Just to clarify, there is a difference between a filesystem and a
> partition.  Partitions contain filesystems.  Put another way, a
> filesystem resides inside a partition.  That distinction is important
> because you can resize a filesystem without resizing the partition
> containing it and vice-versa.  That is, you can shrink a filesystem so
> that it is much smaller than the partition containing it.  Also, you can
> expand a partition without expanding the filesystem.  Most filesystem
> resizing tools prevent the obvious problem of expanding a filesystem
> beyond the partition boundary.  However, most partitioning tools do not
> prevent the problem of shrinking a partition below the filesystem size
> (e.g. fdisk).
>
> Filesystem resizers:
>  - ext2/3 : resize2fs
>  - ntfs : ntfsresize
>  - reiserfs: resize_reiserfs
>
> Partition resizers (any disk partitioning tool):
>  - fdisk
>  - parted
>
> Tools that do both:
>  - qtparted (gui)
>  - gparted (gui)
>
> The tools that do both use some combination of the filesystem and
> partitioning tools behind the scenes, giving the appearance of "resizing
> a linux partition."
>
> BTW, you can play with resizing a filesystem using just files.  For
> example, here's how to create an ext3 filesystem within a file, shrink
> the filesystem without shrinking the file, grow the filesystem, grow the
> file without growing the filesystem, and grow the filesystem:
>
> $ dd if=/dev/zero of=ext3.img bs=1M count=10
>
> $ ls -la --si ext3.img
> -rw-r--r-- 1 rwcitek rwcitek 11M 2007-06-18 12:20 ext3.img
>
> $ mkfs.ext3 -q ext3.img
> ext3.img is not a block special device.
> Proceed anyway? (y,n) y
>
> $ e2fsck -n ext3.img
> e2fsck 1.38 (30-Jun-2005)
> ext3.img: clean, 11/2560 files, 1372/10240 blocks
>
> $ resize2fs -f ext3.img  1372
> resize2fs 1.38 (30-Jun-2005)
> Resizing the filesystem on ext3.img to 1372 (1k) blocks.
> The filesystem on ext3.img is now 1372 blocks long.
>
> $ e2fsck -n ext3.img
> e2fsck 1.38 (30-Jun-2005)
> ext3.img: clean, 11/1280 files, 1208/1372 blocks
>
> $ resize2fs -f ext3.img
> resize2fs 1.38 (30-Jun-2005)
> Resizing the filesystem on ext3.img to 10240 (1k) blocks.
> The filesystem on ext3.img is now 10240 blocks long.
>
> $ e2fsck -n ext3.img
> e2fsck 1.38 (30-Jun-2005)
> ext3.img: clean, 11/2560 files, 1372/10240 blocks
>
> $ dd if=/dev/zero bs=1M count=10 >> ext3.img
> 10+0 records in
> 10+0 records out
> 10485760 bytes (10 MB) copied, 0.037845 seconds, 277 MB/s
>
> $ ls -la --si ext3.img
> -rw-r--r-- 1 rwcitek rwcitek 21M 2007-06-18 12:23 ext3.img
>
> $ resize2fs -f ext3.img
> resize2fs 1.38 (30-Jun-2005)
> Resizing the filesystem on ext3.img to 20480 (1k) blocks.
> The filesystem on ext3.img is now 20480 blocks long.
>
> $ e2fsck -n ext3.img
> e2fsck 1.38 (30-Jun-2005)
> ext3.img: clean, 11/3840 files, 1534/20480 blocks
>
> HTH.
>
> Regards,
> - Robert
>
>
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>
>   
Thanks, sounds like I should just use qtparted (or gparted) and not 
worry about it.