Re: Split from: MyLiveCD Guide

[hasmak]

3) Be able to install a system of any size? // now I enter into hypothesis, because I used only CD's and USB sticks. Actually cloning tools do exist, I don't know them. I can only say : have a partition always larger than the datas you want to put in...

Disk cloning does not create live media, it is mainly used to replicate a system to many machines

Can you let me know about the floppy image?
Cheers

[hasmak]

To Just19, Melodie, AS, Neal
I had a look at mylivecd script.
It appears this is the part that passes the parameters to the compression application
Lines 1091 -> 1103
===========
      my $withgzip;
      if (defined($opts{gzip})) {
        $withgzip = ""
        }
      elsif (defined($opts{lzma})) {
        $withgzip = "-comp lzma"
        }
      elsif (defined($opts{xz})) {
        $withgzip = "-comp xz"
        }
      else {
        $withgzip = "-comp xz -Xbcj x86"
        }
=====================

Can someone help me modify the lines to split the file at the 1GB size
I will tray it on my system

Cheers

[Just17]

mylivecd creates an ISO ......  what you use that ISO for afterwards does not concern it .....  so the ISO can be used on any bootable media that it will fit on .......  CD, DVD, USB etc.

You seem to have misunderstood my post.

Just19
I did misunderstand, sorry
I never attempted a usb boot or install, and I thought that you needed a filesystem and directory tree on the usb
Can you give me a quick summary of what needs to be on the usb?

The boot manager files, and the usual files for accessing a filesystem as well as the vmlinuz etc etc

Have a look at the PCLinuxOS-liveUSB creator utility. Also maybe read some of this thread ...

http://www.pclinuxos.com/forum/index.php/topic,74878.0.html

That extracts the files (isolinux directory & livecd.sqfs file) from the ISO and places them on a partition of a removable drive, sets up the boot manager and writes Grub to the MBR.

That is it  

If that scheme is not used then then problem does not exist = the cat is dead

regards

That is thinking outside the box  
OK, let us define the problem: How to remaster, boot a live system and be able to install a  system of any size?
Would you say this is a fair definition of what we are talking about?

Yes I think that covers it.

So that points me to .....  is it possible to set up a live bootable OS on a USB stick, without compressing all the OS files into one livecd.sqfs file.
If the answer to that is yes, then the file size limit is eliminated, is it not?

After the uncompressed option is proven, then one could maybe choose to compress individual directories or use some other scheme to compress the files for use on limited size media.
Of course it would not be as efficient as a single file ....

Maybe your idea of splitting the .sqfs file might be an easier means to achieving the desired result.

Without lots of testing I wouldn't care to comment on that aspect  

USB has the advantage of cheap and  large and  fast, over the other alternatives for live media.

regards.

NOTE:
            Thanks Neal for forking this discussion off from the other thread  

[AS]

To Just19, Melodie, AS, Neal
I had a look at mylivecd script.
It appears this is the part that passes the parameters to the compression application
Lines 1091 -> 1103
===========
      my $withgzip;
      if (defined($opts{gzip})) {
        $withgzip = ""
        }
      elsif (defined($opts{lzma})) {
        $withgzip = "-comp lzma"
        }
      elsif (defined($opts{xz})) {
        $withgzip = "-comp xz"
        }
      else {
        $withgzip = "-comp xz -Xbcj x86"
        }
=====================

Can someone help me modify the lines to split the file at the 1GB size
I will tray it on my system

Cheers

Hi hasmak,

I'm sorry but the idea of splitting the .sqfs files is not going to work.

The fact is that livecd.sqfs is a compressed filesystem images, upon liveCD boot this file is "loop mounted", to allow decompression on the fly.

Splitting the LiveCD.sqfs means that at some point, before to mount the root fs, you will need to rebuild the liveCD.sqfs file somewhere.

Where exactly ? 

CD/DVD no, because it's read-only,
Hard Disk no, may be already filled or not present at all
RAM ? you need very much RAM more or less like the size of the uncompressed filesystem .... 16 Gb or more ?
Large USB stick ? yes, may be, at this point reconsider the idea from Just19 about a full install on a USB stick. 

AS

[hasmak]

Have a look at the PCLinuxOS-liveUSB creator utility. Also maybe read some of this thread ...

http://www.pclinuxos.com/forum/index.php/topic,74878.0.html

That extracts the files (isolinux directory & livecd.sqfs file) from the ISO and places them on a partition of a removable drive, sets up the boot manager and writes Grub to the MBR.

That is it  

Maybe your idea of splitting the .sqfs file might be an easier means to achieving the desired result.

Without lots of testing I wouldn't care to comment on that aspect  

USB has the advantage of cheap and  large and  fast, over the other alternatives for live media.

regards.

It seams from this that you still needs to create the iso first? or do you?
Maybe you don't, if you run mylivecd with a custome temp and work directories, those directories will not be deleted at the end of the process, I know this for a fact because I remastered my system on an USB HDD and at the end I had both the iso and the livecd.sqfs file. the question is, if you try to remaster a large system and the .sqfs is larger than 4GB, mylivecd will die with an error when it tries to create the iso, but will it delete the livecd.sqfs???
My guess, it will not and you should be able to use that for a bootable live usb.
I can not test that because my system is not large enough.
On more thing, mylivecd will not work with a flash disk as target, it has to be HDD
Let me know what you think
The other way around is to get the compression application to create a multi-part archive, this is not going to be easy, I looked around and it seams  that Linux archivers mostly do not support multi part with the possible exception of 7zip. I have not tried 7zip under Linux and don't know if it can produce .sqfs files
Cheers

Cheers

[hasmak]

I'm sorry but the idea of splitting the .sqfs files is not going to work.

The fact is that livecd.sqfs is a compressed filesystem images, upon liveCD boot this file is "loop mounted", to allow decompression on the fly.

Splitting the LiveCD.sqfs means that at some point, before to mount the root fs, you will need to rebuild the liveCD.sqfs file somewhere.

Where exactly ? 


AS

AS
Thanks
It was always a long shot, but tossing ideas is useful, it opens up other possibilities
Cheers

[AS]

You can perform an installation on USB stick exactly like on HD, you only need a large stick.
This feature is already ready!  USB sticks are going to be cheaper day by day! 

May be you want to explore the possibility to use a compressed filesystem instead of ext2/3/4 ...
This would allow to use compression and at the same time to have a large installable media... on a limited USB stick.

AS

[hasmak]

You can perform an installation on USB stick exactly like on HD, you only need a large stick.
This feature is already ready!  USB sticks are going to be cheaper day by day! 

May be you want to explore the possibility to use a compressed filesystem instead of ext2/3/4 ...
This would allow to use compression and at the same time to have a large installable media... on a limited USB stick.

AS

Thanks
A couple of questions
1- I have a system installed and customized, can I install my system (remastered) as is (not install from the original pclos cd) to a usb stick and have it as a bootable live system?
2- I have a large 2TB usb HDD formatted NTFS, this is my storage device, can I have a compressed .sqfs and boot it without having to format or partition the drive?
Thanks

[Just17]

Assuming that mksquashfs does not have any file size limitation, then the main part of mylivecd could be used to generate the isolinux directory and contents and the livecd.sqfs file.

The generated files could then be used to create a LiveUSB just like would be generated from an ISO ...  except of course the file size limitation would not apply.

regards.

[Just17]

You can perform an installation on USB stick exactly like on HD, you only need a large stick.
This feature is already ready!  USB sticks are going to be cheaper day by day! 

May be you want to explore the possibility to use a compressed filesystem instead of ext2/3/4 ...
This would allow to use compression and at the same time to have a large installable media... on a limited USB stick.

AS

Thanks
A couple of questions
1- I have a system installed and customized, can I install my system (remastered) as is (not install from the original pclos cd) to a usb stick and have it as a bootable live system?

You can use the remaster .... burned to a suitable media ....  to install the remastered OS to any PC. That is one of its main purposes ......  do a remaster and use it on more than one PC for identical installs, to you spec.

Of course you first need to be able to remaster ...... 

2- I have a large 2TB usb HDD formatted NTFS, this is my storage device, can I have a compressed .sqfs and boot it without having to format or partition the drive?
Thanks

Yes & no 

The utility mentioned above requires the filesystem of the PARTITION on which it is installed to be ext.

So a small partition suitable for the live OS is sufficient .....  and the rest of the drive can be whatever fs you wish.

I believe it is possible to use an NTFS fs .....  just have not done so myself.

[Just17]

On more thing, mylivecd will not work with a flash disk as target, it has to be HDD

On what do you base this please?

I haven't tried it, but am surprised ......

[hasmak]

On what do you base this please?

I haven't tried it, but am surprised ......

I have, I tried it on a 8GB Kingston formatted Fat32.
I can't remember the error message now but it definitely could not recognize the drive
You can try for yourself, the message comes on early
Cheers

[AS]

On more thing, mylivecd will not work with a flash disk as target, it has to be HDD

On what do you base this please?

I haven't tried it, but am surprised ......

I have tried using a 4 Gb stick/ext2 fs, and it was working, may be a little slow but working.  

[AS]

On what do you base this please?

I haven't tried it, but am surprised ......

I have, I tried it on a 8GB Kingston formatted Fat32.
I can't remember the error message now but it definitely could not recognize the drive
You can try for yourself, the message comes on early
Cheers

not sure right now, but it seems to remember some issue around grub with fat32 ... not finding stage ...

[Just17]

On what do you base this please?

I haven't tried it, but am surprised ......

I have, I tried it on a 8GB Kingston formatted Fat32.
I can't remember the error message now but it definitely could not recognize the drive
You can try for yourself, the message comes on early
Cheers

Try it with the stick formatted to a Linux filesystem

It is not the media ....  but the filesystem I believe