At Wed, 7 Oct 2026 14:32:00 -0000 (UTC) CGS <[email protected]> wrote:
> > On 2026-10-07, nwe <[email protected]> wrote: > >One of my 32GB USB sticks here I dd copied an ISO-9660 to it then > >formatted the remaining space as an additional partition with > >FAT32. It is not very user friendly, most file browsers do not > >even list that second partition for me until I mount it manually > >at the terminal.</p> > > What's confusing to me is when you write the ISO to the thumb drive it > uses the entire space, though the drive might have a larger capacity > than the ISO itself. So where is the latter written: At the beginning, the > end, > in the middle, or all over the place? Could you have a partition at the > "end" of the drive and use some tool to write the ISO at the "beginning" > so that the end partition is preserved? I've never heard of that being > done; it's always the inverse case, like your own. ISO first, then data > partition (I think the term they used to use was "persistence"). No, using the likes of dd, when you write the ISO image, it "clobers" the partition table. This causes the flash drive to have either no partition table (just the ISO file system) or the partition table set up when the image was created. Either way the full capacity of the flash drive is not "visible". If there is a replacement partition table, that partition table can be amended with fdisk or parted. Originally, the Linux boot (live / install) images were just a raw ISO-9660 file system image, normally ment to be "burned" onto an optical disk (write once CD-ROM or one of the various flavors of writable DVDs). PC BIOS's (before UEFI/Secure boot) would treat a USB drive with an ISO-9660 file system just like a CD-ROM and if it had a bootable signature, would boot it, just like a bootable CD-ROM. I think the newer images, which are meant to be imaged onto flash drives, have a partituon table and a FAT32 UEFI partition, plus the bootable ISO-9660 file system in a separate partition. > > > -- Robert Heller -- Cell: 413-658-7953 GV: 978-633-5364 Deepwoods Software -- Custom Software Services http://www.deepsoft.com/ -- Linux Administration Services [email protected] -- Webhosting Services
