On 16/01/16 17:27, Neil Bothwick wrote: > On Sat, 16 Jan 2016 04:50:49 +0100, meino.cra...@gmx.de wrote: > >> to post a firmware image of my embedded linux computer >> to a friend I want to size it down. >> >> System wise I did that already (only the really necessary >> stuff of Gentoo plus some configuration and addons related >> to the embedded system)...the problem comes with the size of >> the microSDcard I use: 32 GB.... >> >> The microSDcard (source) has two partitions (boot + the rest). >> The boot partition is the first partition and it is of a fixed >> and tiny size. The second partition contains the "rest": Gentoo. >> Currently the used space of this partition is also small. >> >> The image needs to be of a format, which makes >> it possble to 'dd' it onto a microSDcard (target) and afterwards use >> g/parted to resize/expand the second partition to the end >> of the microSDcard to get all storage space available. > > Quick and kludgy. Partition an SD card of the correct size, rsync your > data to it, then dd that card. > > Any other method you use will require you to have a smaller SD card to > test the resultant image, so you may as well use that as the source and > know it works. > >
It is possible to create a dd image of the whole SD card and mount it in a loopback to repartition etc. Mount it then shrink your existing file system (and probably the partition too) to less than the required size, then recreate the dd image to a size still less than the new sd card. On the new card, dd it across until it errors off, then fix/expand the partition and then the file system. You dont care if the end is missing as long as your data is within the size needed. BillK
