I gather the topic here is partition alignment.  (If not, sorry, nevermind:)
My previous experience when looking into this for: fdisk, format, etc.
is that with "modern disks" (pretty much anything that survives today)
partitioning systems should simply use megabyte alignment, and
SHOULD NOT bother about cylinders etc.

On Mon, Jun 10, 2024 at 2:44 PM Eric J Bowman via illumos-discuss
<[email protected]> wrote:
>
> CSM isn't compatible with DDR-6. UEFI's won't have CSM, soon. My only 
> multi-session optical media that works with UEFI-CSM is BD-RE which was never 
> bootable to begin with. If I had some other multi-session media format, I 
> don't think it would work without CSM any better than distro.iso's which 
> forgot -no-emul. Whole lotta Rock Ridge options won't be valid moving 
> forward, due to incompatibility at the "alignment" level, like offsetting an 
> overlapping partition containing the real distro.iso -- at best, gets you 
> 16-bit real mode that only the Intel 8088 MINIX Experience doesn't care about 
> -- due to NVRAM; it just loses access to system RAM w/o CSM.
>
> UEFI says Rock Ridge. UEFI* lists some things which translate to, "won't work 
> without CSM" while hewing to Joliet without saying so, but comes as no 
> surprise because Joliet's Windows. I don't think Joliet's multi-session 
> compatible, but I also note, UEFI allows booting a standard .iso in a 
> partition with an MBR -- not that said MBR is required to point to anything 
> actually existing, which defaults to pointing to -- Windows.
>
> -Eric
>
>
>
> ---- On Mon, 10 Jun 2024 10:54:02 -0700 Eric J Bowman via illumos-discuss 
> <[email protected]> wrote ---
>
> Indeed. But that's the fs inside the .iso, we're trying to fit the .iso into 
> a partition UEFI requires to be at least 1 MiB (which should probably be 
> changed to 2).
>
> -Eric
>
>
>
> ---- On Mon, 10 Jun 2024 10:45:51 -0700 Udo Grabowski (IMK) 
> <[email protected]> wrote ---
>
>
>
> On 10/06/2024 19:24, Eric J Bowman via illumos-discuss wrote:
> > With few exceptions, 'mkisofs -pad' behaves the same way across tools in
> > that it's an arbitrary, static value. The others dial the wrong number.
> > ...
> > Suggest new interop guideline in general -- partition in MiB/GiB using
> > values which are a power of 2. Anyone got any drives laying around they
> > need partitioned? lol, so easy now... if 'mkisofs -pad' behavior were to
> > be "pad to multiple of 65536" would it cause anyone any harm?
> 
> In xa1 mode (muiltisession CD), sectors are 2056 bytes, so that won't
> fit into 65536 ...
> 
> illumos / illumos-discuss / see discussions + participants + delivery options 
> Permalink

------------------------------------------
illumos: illumos-discuss
Permalink: 
https://illumos.topicbox.com/groups/discuss/Te6d81d754118b912-Mfca249b30c9df2563e52f29e
Delivery options: https://illumos.topicbox.com/groups/discuss/subscription

Reply via email to