Syslinux - Jan 2014 - Advice/directions to users of Syslinux

Hi,

i now realized that
  http://www.syslinux.org/wiki/index.php/Hardware_Compatibility#USB-Geometry
 
http://www.syslinux.org/wiki/index.php/Hardware_Compatibility#USB-Miscellaneous
are the new wiki sections by Gene Cumm. (Sorry for not reading
them when they were announced.)

So i ask especially him whether the statement

 "An examle is a drive of 128,64,32 with a partition ending at
  127,63,32 (the last sector of the last whole cylinder)."

should be changed and expanded to

 "An example is a drive of size of 128 MB (or slightly larger)
  assumed with 64 heads per cylinder and 32 sectors per head,
  where the partition should end at 127,63,32.
  Drives larger than 1 GB should be regarded as having 255 heads
  per cylinder and 63 sectors per head. E.g. an drive of
  15794176 blocks (7.5 GB) should have its partition end
  at 982,254,63.
  Drives larger than 16434495 blocks should bear as partition
  end 1023,254,63. Setting the partition end LBA to the full drive
  size may or may not hamper its bootability."

Reasoning:

I state "assumed with 64 heads per cylinder and 32 sectors per head"
because the values of H/C and S/H are more or less a deliberate
decision at partitioning time.

I refrain from giving the drive size in CHS, because this is ambigous
until the user has chosen H/C and S/H.

I do not use digit separators with decimal naumers (15,794,176
versus 15794176) because this could get confused with the CHS
commas.

I mention the opportunity to set the end LBA higher than the end CHS
because else half of a 16 GB drive would be wasted.
But maybe one should rather state that if a BIOS is too dumb for
uneven partiton endings, then it is probably too dumb for large
partitions, too.
Any experience around ? Any opinions ?

The advise to set large drive ends to 1023,254,63 is taken from
  http://en.wikipedia.org/wiki/Master_boot_record#Partition_table_entries


---------------------------------------------------------
To the wiki admins:

I acquired a SYSLINUX wiki account: "scdbackup"
Please enable editing.


Have a nice day :)

Thomas

> Hi,
> 
> i now realized that
>  
http://www.syslinux.org/wiki/index.php/Hardware_Compatibility#USB-Geometry
>  
http://www.syslinux.org/wiki/index.php/Hardware_Compatibility#USB-Miscellaneous
> are the new wiki sections by Gene Cumm. (Sorry for not reading
> them when they were announced.)
> 
> So i ask especially him whether the statement
> 
>  "An examle is a drive of 128,64,32 with a partition ending at
>   127,63,32 (the last sector of the last whole cylinder)."
> 
> should be changed and expanded to
> 
>  "An example is a drive of size of 128 MB (or slightly larger)
>   assumed with 64 heads per cylinder and 32 sectors per head,
>   where the partition should end at 127,63,32.
>   Drives larger than 1 GB should be regarded as having 255 heads
>   per cylinder and 63 sectors per head. E.g. an drive of
>   15794176 blocks (7.5 GB) should have its partition end
>   at 982,254,63.
>   Drives larger than 16434495 blocks should bear as partition
>   end 1023,254,63. Setting the partition end LBA to the full drive
>   size may or may not hamper its bootability."
> 
> Reasoning:
> 
> I state "assumed with 64 heads per cylinder and 32 sectors per
head"
> because the values of H/C and S/H are more or less a deliberate
> decision at partitioning time.
> 
> I refrain from giving the drive size in CHS, because this is ambigous
> until the user has chosen H/C and S/H.
> 
> I do not use digit separators with decimal naumers (15,794,176
> versus 15794176) because this could get confused with the CHS
> commas.
> 
> I mention the opportunity to set the end LBA higher than the end CHS
> because else half of a 16 GB drive would be wasted.
> But maybe one should rather state that if a BIOS is too dumb for
> uneven partiton endings, then it is probably too dumb for large
> partitions, too.
> Any experience around ? Any opinions ?
> 
> The advise to set large drive ends to 1023,254,63 is taken from
>   http://en.wikipedia.org/wiki/Master_boot_record#Partition_table_entries
> 
> 
 
A relatively modern partitioning tool (not from the '80s) would 
already include adequate support for LBA, and for MiB alignment. If 
we are trying to help non-technical users, we shouldn't be adding 
information that could make their lives more complex.

That's why I mentioned in recent emails in this Syslinux mailing list 
that the short answer (which a non-technical user having problems 
with partitions would appreciate) is to:
1_ "create a new DOS partition table";
2_ create a new partition;
3_ format it.

By adding technical details, it makes it harder for a non-technical 
user to follow, and such user will probably go away looking for a 
simpler answer.

If a user doesn't know what "create a new DOS partition table"
means,
there are many ways to find out, including a web search. There are 
many tutorials. There are tools such as GParted Live (and many 
others) specially design to be user friendly. BTW, GParted has 
tutorials and manuals and mailing list and forums. And GParted is not 
the only one.

If a non-technical user finds that following technical instructions 
is a bit (too) difficult, then probably adding technical details is 
not the best way to help them.

As a simple user, I find that some words / wording / writing styles 
can be confusing, or not so clear as originally intended. For 
example, when using words such as "should". Is that a recommendation? 
Is that a requirement? Is that a condition imposed by USB drives? Is 
that a Syslinux requirement? (To clarify, I am not really asking for 
an answer. I am making a point about what a common user might 
interpret from such wording.)

In this particular case, I happen to understand what Thomas is trying 
to explain. But if I put myself in the position of a user that 
doesn't understand the whole partitions / format / booting 
"ramblings", a user who is interested in trying for the first time a 
USB Live Linux distro and not in a whole course about these technical 
matters, I am not sure such user would understand, or be even 
interested in understanding. Add to the mix a user whose native 
language is not English.

Having an adequate partitioning scheme and an adequate formatted 
volume is a requirement to work with these type of (USB) media, not 
just for Syslinux.

If there is one advantage that a simple user can say about Syslinux 
is that it is relatively simple to use.

IMHO, adding information to (and updating documentation already in) 
the wiki is a good thing. But I doubt a simple user would be 
interested in reading and understanding *that* much, specially when 
he is having a problem. Let me put it this way: if I have a problem 
with my car and I can't get to where I need to, I just want the 
problem solved. I might be interested in learning how to repair cars, 
but that's not the moment.

In particular, I would like to avoid even the *perception* that 
Syslinux is difficult, or that is Syslinux the one generating some 
problem with the (USB) media. Syslinux is related to the partitioning 
scheme as much as a spreadsheet or a word processor; it just needs to 
be correctly done.

A correct partitioning scheme (including an adequate MBR's booting 
code) is a necessity for every bootloader, and for using any other 
software on a personal computer.

If I would need to solve these type of problems, I would probably be 
looking on other places, with simple instructions / tutorials.

 
 *** 

In particular, SYSLINUX is not installed in the MBR, like other 
bootloaders (e.g. grub2) might do.

Syslinux has some pros and cons. Each bootloader has them.

Considering the (very) reduced (to say the least) support that "big 
names" are giving to The Syslinux Project, while providing _direct_ 
support for other bootloader projects, I find myself... 
uncomfortable(?) with the idea / implication that The Syslinux 
Project is not making enough to help users with their booting issues. 
In fact, Syslinux makes it simpler for the vast majority of common 
users.

This is just my personal opinion and nothing else.

BTW, I am sure some additional development muscle is very welcome and 
needed, 
and users are eager to see Syslinux improve.

Regards,
Ady.

Am 22.01.2014 10:53, schrieb Ady:
>   
> A relatively modern partitioning tool (not from the '80s) would
> already include adequate support for LBA, and for MiB alignment. If
> we are trying to help non-technical users, we shouldn't be adding
> information that could make their lives more complex.
>
> That's why I mentioned in recent emails in this Syslinux mailing list
> that the short answer (which a non-technical user having problems
> with partitions would appreciate) is to:
> 1_ "create a new DOS partition table";
> 2_ create a new partition;
> 3_ format it.
>
> By adding technical details, it makes it harder for a non-technical
> user to follow, and such user will probably go away looking for a
> simpler answer.
We are adressing two kinds of people:

 1. People who want to create a bootable pendrive, possibly containing
    images from two or three different distributions - we usually can
    expect them to be tech savvy enough to understand those three steps.
    We should probably further point out that a fairly modern tool for
    1+2 has to be used like parted or gparted
 2. People that are creating tools or wrapper script for an install to
    thumb drives. We have to give them some advice that the filesystems
    and geometries of thumb drives are not reliable from factory - we
    might give the the advice to freshly partition/format the users
    thumb drive or at least check the geometry for LBA usability, we
    might further give them an advice how to prepare isohybrid media
    that can be dd'ed to a thumb drive - in many cases this removes the
    need for a separate tool for USB installation

Group 2 might be actively contacted by us. I  am willing to share my 
knowledge on practical usage of isohybrid media and converting isohybrid 
media to properly partitioned media during linux boot.

Regards,
Mattias



-- 
Mattias Schlenker - Redaktion + EDV-Beratung + Linux-CD/DVD-Konzepte
August-Bebel-Str. 74 - 04275 LEIPZIG - GERMANY

Telefon (VoIP "ueberall"), geschaeftlich: +49 341 39290767
Telefon (Festnetz), privat und Fax:       +49 341 30393578
Mobil:                                    +49 163  6953657
Mobil (SIM in Testgeraeten):              +49 1578 3499550

Bitte fuer geschaeftliche Telefonate vorzugsweise die VoIP-Telefonnummer
+49 341 39290767 verwenden, da ich diese aufs Mobiltelefon routen kann!

Hi,
> 1_ "create a new DOS partition table";
> 2_ create a new partition;
> 3_ format it.
This could be added to
  http://www.syslinux.org/wiki/index.php/SYSLINUX#Creating_a_Bootable_Disk
statement: 

  "In order to create a bootable disk using SYSLINUX, prepare
   a normal MS-DOS formatted disk."

Like

  "If in doubt, make a backup of your disk content, create a new
   DOS partition table, create a new partition, and format it.
   Take care not to spoil your other disks."

plus

  "With persistent problems to boot USB connected pen drives see
   the section about 
  
[http://www.syslinux.org/wiki/index.php/Hardware_Compatibility#USB_related_problems
USB related problems]."

> when using words such as "should". Is that a recommendation?
Yes. Nothing is absolute with that topic.
Some combinations work, some don't. It should work
with the "should" recommendations.

I propose to extend Gene's existing statements in
 
http://www.syslinux.org/wiki/index.php/Hardware_Compatibility#USB-Miscellaneous

This is a trouble oriented page, which names possible technical
reasons for problems. 
Some of them are good for a ROFL. E.g.
 
http://www.syslinux.org/wiki/index.php/Hardware_Compatibility#Problematic_CD-ROM_controllers

> I am sure some additional development muscle is very welcome and 
> needed
I feel apt for ISO 9660 related issues, up to isohybrid
with MBR, GPT, and APM. My boot knowledge is collected at
 
http://bazaar.launchpad.net/~libburnia-team/libisofs/scdbackup/view/head:/doc/boot_sectors.txt


Have a nice day :)

Thomas

Hi,

Ady wrote:
> I would suggest adding an internal link to respctive sections of the 
> wiki, not more text in the same page.
This is reasonable.
Please have a look at
  http://www.syslinux.org/wiki/index.php/User:Scdbackup  

The first section shall become the new text of
  http://www.syslinux.org/wiki/index.php/SYSLINUX#Creating_a_Bootable_Disk

The second section shall become a new section
  Bad Heritage on MS-DOS disk
in
  http://www.syslinux.org/wiki/index.php/Common_Problems


[about USB Geometry]
> My point was about the several possible ways such wording could be 
> interpreted by different users when reading them in the Syslinux 
> wiki.
I meanwhile united the section "USB Miscellenous" with
  http://www.syslinux.org/wiki/index.php/Hardware_Compatibility#USB-Geometry
Now it is a bit too long but does not show an artificial
separation of general statements and examples.
It is a vague as needed and as tangible as possible, i think.

Please have a look and criticize. Any objection is welcome.


Have a nice day :)

Thomas

In message <BLU0-SMTP218A5F5400BB0FCA0312DC28BA70 at phx.gbl>, Ady wrote:
>By adding technical details, it makes it harder for a non-technical 
>user to follow, and such user will probably go away looking for a 
>simpler answer.
Yes.
>If a user doesn't know what "create a new DOS partition table"
means,
>there are many ways to find out, including a web search.
I know what it means, but I have (at least) three different ways to
do it that I can think of right off the top of my head, i.e. use
Windows itself to do it, use Gparted/GpartedMagic, or use FreeBSD,
which can also do it.  Other people can probably expand this list.

My point is that just commanding a user to "create a new DOS partition
table" may not be sufficiently specific to achieve the desired result,
as some or all of these tools may perhaps be creating partitions in
a manner that is incompatible... with some thing or another.
>Having an adequate partitioning scheme and an adequate formatted 
>volume is a requirement to work with these type of (USB) media, not 
>just for Syslinux.
Apparently, yes.  And it seems to me that the simplest way (from the
point of view of the end user) to insure that these things are done
correctly is for the distributors of tools such as Clonezilla,
Ultimate Boot CD, and OpenELEC to follow in the footsteps of, e.g.
the Archlinux folks and the Debian folks and the LessLinux folks
i.e. by just simply distributing images that can be (no-brainer)
block-by-block copied onto USB sticks in order to produce a working
stick... using either dd or whatever the bleep its counterpart on
Windows/DOS might be.

In fact, the more I think about it, the more I think that it is
rather entirely ill-advised for Clonezilla to have four different
recommended install procedures for Windows and an additional three
different procedures for Linux.  Even just from a strictly technical
support (cost) standpoint, this seems to be an extraordinarily poor
choice.
>IMHO, adding information to (and updating documentation already in) 
>the wiki is a good thing. But I doubt a simple user would be 
>interested in reading and understanding *that* much, specially when 
>he is having a problem. Let me put it this way: if I have a problem 
>with my car and I can't get to where I need to, I just want the 
>problem solved. I might be interested in learning how to repair cars, 
>but that's not the moment.
Well said.

In an ideal universe a "simple" end-luser shouldn't have to know a
single
bloody thing about partitions, partition tables, drive geometry, for-
matting, or any of that stuff.  Nor should any such ordinary end-luser
ever feel the need to look at ANY PART of the Syslinux Wiki.  Why should
they, if their only goal is, for example, to watch a bloody video on their
TeeVee (using e.g. OpenELEC)?

The Syslinux Wiki and the material in it should be helpful to the kinds
of folks who are constructing bootable images.  but all of the thought,
planning, and heavy lifting... including all of the partitioning,
formatting, etc... necessary to create a working USB stick should already
have been done... by the image preparer... well before the end-luser
clicks on that download button.

The way to make all of this stuff maximally simple for real end-lusers
(including me) is for the Syslinux project to STRONGLY suggest to its
direct user base that they all make it a point to distribute simple,
pre-partitioned, pre-formatted dd-able images.


Regards,
rfg