From: jdow <jdow@earthlink.net>
To: Martin Steigerwald <martin@lichtvoll.de>
Cc: Michael Schmitz <schmitzmic@gmail.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Matthew Wilcox <willy@infradead.org>,
David Sterba <dsterba@suse.cz>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Jens Axboe <axboe@kernel.dk>,
linux-m68k <linux-m68k@lists.linux-m68k.org>
Subject: Re: Amiga RDB partition support for disks >= 2 TB
Date: Thu, 28 Jun 2018 05:31:18 -0700 [thread overview]
Message-ID: <6b25bd4b-d218-55a0-6687-b17fbf7e5c97@earthlink.net> (raw)
In-Reply-To: <51008870.LIDn3ZZdjm@merkaba>
On 20180628 04:38, Martin Steigerwald wrote:
> Martin Steigerwald - 28.06.18, 13:30:
>> jdow - 28.06.18, 12:00:
>>> On 20180628 01:16, Martin Steigerwald wrote:
>> […]
>>
>>>>> That brings to the fore an interesting question. Why bother with
>>>>> RDBs
>>>>> over 2TB unless you want a disk with one single partition? This
>>>>> Win10
>>>>> monster I am using has a modest BIOS driver partition for the OS
>>>>> and
>>>>> a giant data partition. That smaller partition would easily work
>>>>> with
>>>>> any RDB/Filesystem combination since 2.0. So there are some good
>>>>> workarounds that are probably "safer" and at least as flexible as
>>>>> RDBs, one Linux has used for a very long time, too.
>>>>
>>>> Well, my use case was simple:
>>>>
>>>> I had this 2 TB disk and I choose to share it as a backup disk for
>>>> Linux *and* AmigaOS 4.x on that Sam440ep I still have next to me
>>>> desk here.
>>>
>>> EEEEEEK! The hair on my neck is standing up straight! Have you heard
>>> of SAMBA? The linux mail server firewall etc machine has an extra
>>> 4TB
>>> disk on it as a backup for the other systems, although a piddly 4TB
>>> is small when I save the entire 3G RAID system I have. It's a proof
>>> of concept so.... A full backup on a 1gig Ethernet still takes a
>>> looooong time. But backing up even an 18GB disk on an Amiga via
>>> 100Base-t isn't too bad. And disk speeds of the era being what they
>>> were it's about all you can do anyway.
>>
>> Heh, the thing worked just fine in Amiga OS 4. I got away with it
>> without an issue, until I plugged the disk to my Linux laptop and
>> wrote data onto the Linux file system. Mind you, I think in that
>> partition marked LNX\0 I even created a Linux LVM with pvcreate. Do
>> you call that insane? Well it probably is. :)
>>
>> And as an Amiga user I could just return to you: I clicked it, it did
>> not warn, so all is good :)
>>
>> But yeah, as mentioned I researched the topic before. And I think
>> there
>> has not even been an overflow within the RDB:
>>> The raw, theoretical limit on the maximum device capacity is about
>>> 2^105 bytes:
>>>
>>> 32 bit rdb_Cylinders * 32 bit rdb_Heads * 32 bit rdb_Sectors * 512
>>> bytes/sector for the HD size in struct RigidDiskBlock
>>
>> http://wiki.amigaos.net/wiki/RDB_(Amiga_Rigid_Disk_Block)
>>
>> Confirmed by:
>>
>> The .ADF (Amiga Disk File) format FAQ:
>> http://lclevy.free.fr/adflib/adf_info.html#p6
>>
>> But what do I write, you know the RDB format :)
>>
>> So just do the calculation in 96 Bit and you all are set :)
>
> For sectors.
>
> Or
>
> 3*32+9 (for 512 bytes per sector) = 105 bits
>
> for bytes.
>
>> Now that is a reason for 128 Bit CPUs :).
>>
>> Muuhahaha.
And if you make the logical block size 65536 you need 128 bits or 10^something
big = 2^128.
{^_-}
next prev parent reply other threads:[~2018-06-28 12:31 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-25 15:46 Moving unmaintained filesystems to staging Matthew Wilcox
2018-04-25 15:47 ` Christoph Hellwig
2018-04-25 20:30 ` David Sterba
2018-04-26 2:57 ` Matthew Wilcox
2018-04-26 10:28 ` moving affs + RDB partition support to staging? (was: Re: Moving unmaintained filesystems to staging) Martin Steigerwald
2018-04-26 10:45 ` moving affs + RDB partition support to staging? John Paul Adrian Glaubitz
2018-04-26 10:59 ` David Sterba
2018-04-26 11:06 ` John Paul Adrian Glaubitz
2018-05-06 0:59 ` Al Viro
2018-05-06 7:40 ` Al Viro
2018-05-06 20:46 ` Al Viro
2018-05-06 20:49 ` John Paul Adrian Glaubitz
2018-05-06 21:32 ` Al Viro
2018-05-07 2:15 ` Al Viro
2018-05-07 2:40 ` Michael Schmitz
2018-05-07 7:08 ` Martin Steigerwald
2018-05-07 20:50 ` Michael Schmitz
2018-05-07 20:56 ` Ingo Jürgensmann
2018-05-07 20:58 ` John Paul Adrian Glaubitz
2018-05-06 8:40 ` John Paul Adrian Glaubitz
2018-05-06 10:12 ` Martin Steigerwald
2018-04-26 11:00 ` moving affs + RDB partition support to staging? (was: Re: Moving unmaintained filesystems to staging) Christoph Hellwig
2018-04-26 11:08 ` Geert Uytterhoeven
2018-04-26 23:56 ` Finn Thain
2018-04-27 1:43 ` moving affs + RDB partition support to staging? jdow
2018-04-27 1:26 ` jdow
2018-05-06 8:52 ` John Paul Adrian Glaubitz
2018-05-06 10:10 ` Martin Steigerwald
2018-05-07 4:54 ` jdow
2018-04-27 2:11 ` moving affs + RDB partition support to staging? (was: Re: Moving unmaintained filesystems to staging) Michael Schmitz
2018-06-24 9:06 ` Martin Steigerwald
2018-06-24 11:33 ` moving affs + RDB partition support to staging? jdow
2018-06-24 11:40 ` jdow
2018-06-26 2:23 ` Michael Schmitz
2018-06-26 5:17 ` jdow
2018-06-26 8:12 ` Martin Steigerwald
2018-06-26 9:46 ` jdow
2018-06-26 8:31 ` Michael Schmitz
2018-06-26 9:45 ` jdow
2018-06-27 1:07 ` Michael Schmitz
2018-06-27 6:24 ` jdow
2018-06-27 8:03 ` Martin Steigerwald
2018-06-28 2:57 ` jdow
2018-06-28 7:40 ` Amiga RDB partition support for disks >= 2 TB (was: Re: moving affs + RDB partition support to staging?) Martin Steigerwald
2018-06-27 9:00 ` moving affs + RDB partition support to staging? Michael Schmitz
2018-06-28 3:44 ` jdow
2018-06-28 5:43 ` Michael Schmitz
2018-06-28 6:39 ` jdow
2018-06-28 8:16 ` Amiga RDB partition support for disks >= 2 TB (was: Re: moving affs + RDB partition support to staging?) Martin Steigerwald
2018-06-28 10:00 ` Amiga RDB partition support for disks >= 2 TB jdow
2018-06-28 11:30 ` Martin Steigerwald
2018-06-28 11:38 ` Martin Steigerwald
2018-06-28 12:31 ` jdow [this message]
2018-06-28 8:07 ` Amiga RDB partition support for disks >= 2 TB (was: Re: moving affs + RDB partition support to staging?) Martin Steigerwald
2018-06-27 7:57 ` moving affs + RDB partition support to staging? Martin Steigerwald
2018-06-28 2:56 ` jdow
2018-06-26 8:02 ` Martin Steigerwald
2018-06-26 8:40 ` Michael Schmitz
2018-06-26 9:31 ` jdow
2018-06-25 7:53 ` moving affs + RDB partition support to staging? (was: Re: Moving unmaintained filesystems to staging) Michael Schmitz
2018-06-25 8:26 ` Martin Steigerwald
2018-06-25 8:40 ` Geert Uytterhoeven
2018-04-27 8:01 ` Martin Steigerwald
2018-04-26 4:58 ` Moving unmaintained filesystems to staging Nikolay Borisov
2018-04-26 5:30 ` Willy Tarreau
2018-04-26 6:11 ` Pavel Machek
2018-04-26 10:36 ` Martin Steigerwald
2018-05-03 9:18 ` Pavel Machek
2018-04-27 1:10 ` Luis R. Rodriguez
2018-04-29 12:07 ` Greg KH
2018-04-29 20:07 ` Ondrej Zary
2018-04-29 23:37 ` Greg KH
2018-05-01 10:14 ` Pavel Machek
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