Your response is helpful Lennart, and this ignorant ex-mainframer even believes he understands. Thank you. before going further, since my disks are empty, based upon this from the internet: MBR is compatible with legacy and older operating systems that do not support GPT. On the other hand, if you have a newer computer with UEFI firmware, GPT is recommended for better compatibility and support for modern features.Jul 11, 2023 should i format with a GPT partition table? IIRC every system I have seen (other than Sun) has had a MBR partition table. to make sure my older computers can access it (hopefuly won't need to), will any operating system that supports 4 terabyte filesystems support GPT? ---------------------------------- practically and realistically, I would still suggest that gparted could and should recognize a few of the most common file-systems, including microsoft and apple. ditto linux itself. As I understand it, linux for some time has recognized GPT partition tables, even though it would always create MBR, so if it doesn't have to recognize microsoft formats, the same argument could be made that it should (historically have) ONLY recognized MBR partition tables. Will linux access an amiga filesystem? Willow? Netware? CP/M? I suspect the number of filesystems a running LINUX can actually access is small enough that adding code to recognize them without a partition table entry is reasonable. Has microsoft changed? Last I knew (thought I knew), it could not access or be aware of ext4 files at all unless special modifications were applied to it. And "irregardless" (intentionally trying to add some levity to this) I would hope WE could be one (or two, or three) better then Microsoft. In practical terms, I am not going to walk into Microcenter and buy a spinning/solid state/usb drive with an Amiga file-system on it. A new and easy to acquire drive will contain --a partition table that identifies the file-systems on it) --an empty partition table --a microsoft filesystem --if removed from a computer sold with linux, an EXT4 or maybe one of a short list, but I suspect ONLY with a partition table. And once I have defined partitions, gparted and/or the linux install process WILL format it at least in linux and (some?) microsoft formats, so it DOES understand them. I have never tried formatting a partition for amiga with gparted... but if so, might that be useful for running an amiga emulator? Since apparently disks with one of a few microsoft filesystems are "common", I think it is reasonable for both Linux AND gparted to recognize them. If I have pulled a disk out of some other computer, I should be expected to have the knowledge of how to check for a filesystem in THAT format. another aside, just out of curiosity: If I find a mainframe storage array (in a dumpster, or "fell off a truck") made from commodity disks, do they have one of the two partition tables, and a filesystem we might know about, or just some hidden binary that only the mainframe controller knows about? <pre>--Carey</pre>
On 10/24/2024 8:13 AM CDT Lennart Sorensen <lsorense@csclub.uwaterloo.ca> wrote:
On Wed, Oct 23, 2024 at 03:51:24PM -0500, CAREY SCHUG via talk wrote:
a partition table is just binary ones and zeros.
there are different kinds of partition tables.
it has to read the ones and zeros to determine if, or which kind of, partition table is there.
winblows reads those ones and zeros, determines it is NOT a partition table, but that it *IS* a filesystem.
If you put ext4 on a disk without partitions, windows would not recognize it had a filesystem. Windows can only do that because it recognized the filesystem type and knew what to do with it. Try connecting a drive with an Amiga FFS and see what windows does. Either nothing, or helpfully offers to format the drive for you to make it "usable".
There are hundreds of possible filesystems you could put on there. Why (and even how) could parted know how to recignize them all?
About the best it could do if you go to partition the drive is say 'hey the sector for the partition table is not all zero, are you sure you want to create a new partition table here?'
why is gparted too unwilling to do that?
Because it is an impossible task. There is no magic indicator that something is a filesystem. You need to check for the specific header layout of each particular filesystem to detect it. This is why the file tool has a database of magic signatures to recognize all sorts of things. Perhaps parted could instead ask file what it things is on the disk and display that.
For example: lsorense@mythtv64:~$ sudo file -s /dev/sdh /dev/sdh: DOS/MBR boot sector lsorense@mythtv64:~$ sudo file -s /dev/sdg /dev/sdg: DOS/MBR boot sector; partition 1 : ID=0xee, start-CHS (0x0,0,2), end-CHS (0x3ff,255,63), startsector 1, 4294967295 sectors, extended partition table (last) lsorense@mythtv64:~$ sudo file -s /dev/sdg1 /dev/sdg1: Linux Software RAID version 1.2 (1) UUID=e0555ca7:7af8ef1c:d29d1583: e18e5a7 name=mythtv64:1 level=6 disks=9 lsorense@mythtv64:~$ sudo file -s /dev/sda1 /dev/sda1: Linux Software RAID version 1.2 (1) UUID=e0555ca7:7af8ef1c:d29d1583: e18e5a7 name=mythtv64:1 level=6 disks=9 lsorense@mythtv64:~$ sudo file -s /dev/sdf1 /dev/sdf1: Linux Software RAID version 1.2 (1) UUID=e0555ca7:7af8ef1c:d29d1583: e18e5a7 name=mythtv64:1 level=6 disks=9 lsorense@mythtv64:~$ sudo file -s /dev/sdh1 /dev/sdh1: Linux rev 1.0 ext4 filesystem data, UUID=85a0326e-99b6-4a83-9931-6a59cf36140f (needs journal recovery) (extents) (large files) (huge files)
Took me a few tries to find one that wasn't a raid volume. :)
just as a safety mechanism. If I try to do something, is asks me several times, "are you sure?", all data will be wiped out. maybe if it can, it should warn me there is data on the disk that that will be wiped out if I make any changes.
maybe I'm confused on details.
is there a function in gparted to figure out what is on the disk?
I don't think so. It's just is just to display, create and modify various partition table formats. Filesystems and data are outside it's scope. It tries to follow the unix philosophy of doing one thing well.
Maybe I need to invoke such an option. or is it a different program?
As you see, file is good at telling what things are.
-- Len Sorensen