Re: Resize a disk image from 32G to 4G or copy u-boot?
On Tuesday 24 March 2020 16:44:42 Alan Corey wrote:
> Downsizing requires that no files are in the part you trim off.
> Upsizing can sometimes be done by deleting the partition and
> recreating letting fdisk use the maximum size. Don't format between
> or anything and in case you have to type the numbers in you should
> have a copy of them handy like
> Device Boot Start End Sectors Size Id Type
> /dev/sda1 63 2056319 2056257 1004M 6 FAT16
> /dev/sda2 2056320 43022069 40965750 19.5G 83 Linux
> /dev/sda3 43022070 657427994 614405925 293G 83 Linux
> /dev/sda4 657427995 1953520064 1296092070 618G 5 Extended
> /dev/sda5 657428058 1953520064 1296092007 618G 83 Linux
> I used to hide a partition on a Windows machine by deleting it then
> recreating it when I wanted it, the data in it was fine. This scheme
> may not work on GPT especially because it puts the partition table at
> the end of the disk.
>
> I would try using dd to copy the whole device like /dev/sda instead of
> /dev/sda1 which should get the uboot., Then you just need to upsize
> the second partition. Or use dd to copy the uboot partition then
> create and format the 2nd one manually and copy the files over with
> cp. Unless uboot needs to know the offset of something in the 2nd
> partition.
>
> Such tiny SD cards...
And nothing so far, and I have been watching, in the way of reducing a
filesystem to only the actual size occupied. Then it can be backed up
with dd and recovered, rewritten by dd, at a reasonable size for
storage. And re-expanded to fit the media it finds. All of my attempts
to do that with dd alone have been thwarted by the fact that I have yet
to find two u-sd's marked as such and such a capacity, that actually
were the same size.
Our tools simply have not kept up with the technology. So I wind up doing
my backups with amanda and that hasn't kicked my applecart and spilled
it yet. But amanda works a bit different and most read the docs and run
screaming to the hills because theres no easy way to make a full backup
on Friday nights. Amanda doesn't need to, its got your data covered
anyway.
> On 3/24/20, Nate Bargmann <n0nb@n0nb.us> wrote:
> > Hi All.
> >
> > I have an Olimex LIME2 based Freedombox (Debian Buster) and as I am
> > using an external hard drive with it, less than 2 GB of the 32 GB
> > micro-SD card capacity is being used. I have a spare 4 GB card that
> > I would like to use instead, but haven't figured out how to downsize
> > the root partition in the disk image file after using dd to make an
> > image from the 32 GB card.
> >
> > I tried the steps at:
> >
> > https://softwarebakery.com/shrinking-images-on-linux
> >
> > and gparted fails at the resize step with an error of:
> >
> > btrfs filesystem resize 1:2234368K ʼ/tmp/gparted-3ExAC9ʼ
> > 00:00:05 ( ERROR )
> >
> > Resize ʼ/tmp/gparted-3ExAC9ʼ of ʼ1:2234368Kʼ
> > ERROR: unable to resize ʼ/tmp/gparted-3ExAC9ʼ: No space left on
> > device
> >
> > Even if I manually try to use the btrfs command to attempt the
> > resize I get the same error which seems weird as I am *shrinking*
> > the file system..
> >
> > As an alternative, I created the proper partitions on the 4 GB card
> > and used rsync to copy the relevant data over. That is all well and
> > good except that now I don't have u-boot in the first 1 MB of the 4
> > GB card (the boot partition starts at sector 2048 in both the disk
> > image and the 4 GB card). I'm unsure of the exact offsets or I
> > would simply use dd to copy that data from the 32 GB image to the 4
> > GB card and be on my way.
> >
> > Ideas?
> >
> > TIA
> >
> > - Nate
> >
> > --
> >
> > "The optimist proclaims that we live in the best of all
> > possible worlds. The pessimist fears this is true."
> >
> > Web: https://www.n0nb.us
> > Projects: https://github.com/N0NB
> > GPG fingerprint: 82D6 4F6B 0E67 CD41 F689 BBA6 FB2C 5130 D55A 8819
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/gene>
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