Thank you again Lennart, this ignorant mainframer is slowly being dragged kicking and screaming into the modern age. 1. Linux (the whole thing, not the kernal) should handle random hardware as well as any major competitiors, at least windows and IOS. --any commodity devices sold at retail should just work. I <pre>--Carey</pre>
On 10/26/2024 10:35 PM CDT Lennart Sorensen <lsorense@csclub.uwaterloo.ca> wrote:
On Fri, Oct 25, 2024 at 02:59:48AM -0500, CAREY SCHUG wrote:
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?
Well the largest disk MBR can handle (assuming it uses 512 byte sectors which most still do), is 2TB. Anything bigger has to use 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.
The linux kernel has support GPT since the late 90s since it was part of EFI for the Itanium so it had to be supported to work with that architecture. Later when x86 moved to UEFI GPT came along.
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.
To a large extent the answer is that yes it can. For example:
mythtv64:~/gp# find /lib/modules/6.11.2-amd64/kernel/fs/affs/ /lib/modules/6.11.2-amd64/kernel/fs/affs/ /lib/modules/6.11.2-amd64/kernel/fs/affs/affs.ko.xz mythtv64:~/gp# modinfo affs filename: /lib/modules/6.11.2-amd64/kernel/fs/affs/affs.ko.xz license: GPL description: Amiga filesystem support for Linux
I think warning about not blank is enough. You can then go use file to check what it contains and get much better results from a tool designed and maintained for exactly the purpose of identifying things.
But certainly you could expect to encounter a drive without partitions with some file system (NTFS, exFAT, FAT or even HFS+) or a partition table, usually MBR or GPT (since the mac has used GPT for years now ever since moving to x86 and not ARM processors). Hitting a partition table from Amiga or BSD or AIX or something else is highly unlikely.
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.
Definitely no change there that I am aware of.
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.
What if it contains an MBR and a GPT partition table? They are not in the same sector locations by design. What if it has GPT but the two copies are not in sync?
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?
Of course parted is far from the only partitioning tool on linux. It is certainly NOT the one I would pick to use if partitioning a drive. cfdisk is so much more pleasant to work with.
I will use gparted if I need to resize partitions on a drive though. About the only think I will consider using it for.
Disk partitioning is a somewhat complicated thing, although at least on modern machines it is much much nicer than the insanity you used to have to do on Solaris or IRIX or those other old unix systems where you had to tell it the drive geometry and then create disk labels all manually.
-- Len Sorensen