Problem continuing a multisession CD. (Solved)

Discuss anything specific to using Puppy on a multi-session disk
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gcmartin

#31 Post by gcmartin »

I have been testing other items that @Ted Dog has done and your RAM2SFS you sent is on the list. I had noticed that it was not posted in the thread and had assumed that you have plans, by your answers, that you are planning such.

I view your assistance as value and if you agree, I will create a manual demonstrating how to go forward.

My questions is such that I have a clearer picture of what you propose and what is to occur so that the path is crystal.

@Ted Dog and @Flash are aware that this is a topic of interest to me, as it is directly in line with where I, for years, had wondered if there is such a path. Thanks to @Ted Dog's progress on this and "removable media", much has occurred in Blu-ray, DVD, UEFI, and 64bit use.

Hope this makes clear why I am trying to clarify with my questions. Your assistance and guidance has not been unnoticed ... and is appreciated.

There is no oversight. Just trying to see the path to a new Live-DVD/Live-Blu-ray clearly.

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Ted Dog
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#32 Post by Ted Dog »

yes real life is getting in the way of my hobby time... Nothing too bad, actually some may be a distraction with as good outcomes however to early to tell.. Looks like a week of new toys to play with and check out. The Elio car thangy is going to be on display in Austin and San Antonio next week. Talked with them about open sourcing the car brains or pre planning for power 5v 4A for additional goodies like a FatdogARM infotainment idea and basically trying to get them to be a TechnoTweeking platform.. Price point and cool factor already exists.. :wink:

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Flash
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#33 Post by Flash »

Carlos, have all your questions been answered?

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#34 Post by Disco Makberto »

Hello, Jasper!

Thanks for your invaluable help.

The tool "ram2sfs" is certainly an option, and I appreciate your assistance very much. In addiiton to your tool, I also would like to explore other options that are capable of producing an all-in-one traditional SFS that can be used in lieu of an SFS from a liveCD to produce a pup liveCD, assuming those options are viable.

The other tool, "reburn", is also an option. But I was thinking in the lines of using an ISO manipulator. By using an ISO manipulator, I can replace the "normal" SFS with my "all-in-one" SFS, then burn the new ISO to CD or DVD, and have a new pup liveCD.

My plans, before arriving to the final desktop at which point I am thinking about doing a remaster, is doing the changes via multisession. Thus, I change or add something, then save to multisession; then, next day or so, I change or add something, then save to multisession; then again next day or so, I change or add something, then save to multisession; and on and on until I get everything I want.

I am still not ready to complete my little project, but I have about 70% to 80% sorted out. There are still some issues (not related to multisession or remastering) that I still need to work on or ask in the forum.

All the very best,

Carlos Albert
D-Mak

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#35 Post by Disco Makberto »

Flash wrote:Carlos, have all your questions been answered?
Hi, Flash!

Thanks for asking.

Yes, I still would like to know the difference between "defragmenting a live disc" via a multisession CDR or multisession DVDR versus "defragmenting a live disc" via a multisession CDRW or multisession DVDRW. Please read message number 20 where I originally asked this.

Cheers,

Carlos Albert
D-Mak

gcmartin

#36 Post by gcmartin »

Hi Carlos, I hope this explains a little in concept, which BTW, you may already understand. In disk storage, files are created and destroy randomly over time. And there are times when existing files are expanded or decrease in sizes. The writing of files are done in blocks on sectors that may or may not be contiguous. The drives, themselves insure that the files have pointers linking it together, even though, over time file-blocks can get scattered because there was no way to keep all of a given file in a contiguous sequence. The I/O subsystem which writes this stuff invalidates blocks associated with this kind of file activity and many files can and do become scattered over spaces on the HDD. This scattering is ins known as fragmenting. Defragmenting attempts to take all of the files and repacks them in a somewhat sequential layout.

In multi-session CD/DVD discs, ALL DATA is written contiguously so there is little chance that a particular file can be broken into blocks and interspersed among other blocks of other files in a scatter manner. Even when a given file is edited and saved, when the session is finally written out, all change files are written intact, sequentially. Thus, since all is done in an almost single-file sequential operation, But, when running a shutdown session, ALL files, including the changed files are written sequentially. Thus, over the life of a Live DVD, you may have created/changes certain files many multiples of time and this may be encased in many save-session files on disc. Since everything is sequential, there is no equivalent concept of fragmentation, nor defragmenting with DVD/CD multisession.

So to handle the fact that the same file had been deleted/rewritten by changes from its original, there can be procedures involved which accounts for those occurrence.

You may have already noticed that to have occurred, where a file that you used was changed and you found on reboot, the changed file, while not knowing that the original file save in an earlier session still exist on the DVD/CD media even though you are looking at the most current version.

How is this reconciled, well, at boot time, the Linux technology layers the most current data on top of the originals so that when it gets to desktop, only the most current version is seen.

As such, a remaster kinda does the same thing when run as it takes the original system and replaces any data that is newer with current data, then rewrites this into an ISO (or file system folder). Now, when that ISO is written to a new disc (or a CDRW/DVDRW) it is done in a sequential manner as described above. This process of recreating the system with new data can be loosely worded as "defragmenting", for it re-combined all of the data together so that there are not multiples floating around on media disc. You can rewrite a CDRW/DVDRW many times, but, this cannot be done using CDR/DVDR that has been written to. You can add, but, you cannot rewrite as can be done with RWs ("ReWritables") versions

Hope this provide some clarity. Again, much of this you may already know.

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#37 Post by Disco Makberto »

Hello, Gcmartin!

Thanks for your explanation.

Yes, I know that "defragmenting a live disc" is not really proper terminoloy, but that is how Flash calls it, and I think that he invented the trick. Probably a better a description would be "decreasing the amount of date folders" resulting in a new live disc that contains all the info from the old disc. By the way, now that we are at it, do you know why following this trick sometimes ends up with just one date folder while some other times it ends up with two date folders? What determines if it is one or two date folders?

I have been confused with this statement by Flash:
Flash wrote:If you run multisession Puppy from a rewritable CD or DVD, you don't even have to put in a new disk; Burniso2cd will burn the iso to the multisession disk you've been running Puppy from, then it is burned you just Save to it. The danger is that if the burning or save process doesn't go right, you no longer have your old multisession disk to fall back on. So it's better to transfer to a different disk. I use DVD+RWs and leapfrog them. Once I'm sure the new disk works, the old one goes into the pile to be reused for the next test.
Let's say that we have a multisession CDRW or DVDRW disc and we want to "defragment it" (as Flash would say). Why can we write the base ISO to this same disc? If we do this, wouldn't we be deleting the old info on it? If we use a CDR or DVDR, on the other hand, we would need a new disc with the base ISO already on it. To be more specific, with a multisession disc and the "defragmenting" trick, why is it possible to burn the base ISO on the same disc if we use CDRW or DVDRW while we have to use a different disc with the base ISO already on it if we use CDR or DVDR?

Carlos Albert
D-Mak

Jasper

#38 Post by Jasper »

Hi Carlos et al,

I sent ram2sfs to gcmartin last week and since his avowed promise is to write a Multi-session manual I’ll leave it to him to make it available and to answer any questions on all aspects of Multi-session.

Even if I could type at the rate of 212 words per minute - to make an updated iso (post ram2sfs) and burn it - it would take at least 4 times longer to make an identical DVD than using “reburn
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Disco Makberto
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#39 Post by Disco Makberto »

Greetings, Jasper!

Thank you very much for all your support.

Unfortunately, I don't have any experience with using Puppy Linux on USB sticks or alike. All my experience is limited to liveCD's. Even my working Windows OS is on liveCD. That doesn't mean that using a USB stick is not advantageous, for it certainly is, so I agree with what you said.

I am really looking forward to trying your applications.

Cheers,

Carlos Albert
D-Mak

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Flash
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#40 Post by Flash »

Carlos, have you actually burned a multisession CD or DVD and tried out any of the things you've been asking about? In particular, have you tried a rewritable CD or DVD?

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#41 Post by Disco Makberto »

Hey, Flash!

Yes, but not with DVD-+RW's (or CD-RW's, for that matter). The problem is that, in my area, I cannot find a supplier that can sell just a few discs or so. My local dollar store sells discs in bundles of 3, but not RW's. At any rate, I can try eBay to try to get a couple of RW's.

Regards,

Carlos Albert
D-Mak

P.S.: Most of the time I use DVD+R's, The remaining are DVD-R's and CD-R's.

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Flash
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#42 Post by Flash »

Well, the only difference between using a rewritable disk and a write-once disk is that you can re-use the rewritable disk. What that means in practice is, Burniso2cd will simply overwrite whatever is on the rewritable disk if you tell it to burn a Puppy iso onto the disk. If you tell it to burn the same Puppy iso as was already on the multisession disk you booted from, then you'll wind up with a freshly burned live Puppy, the same as if you'd started with a blank write-once disk. After that, you just tell Puppy to Save and you'll have a "defragmented" multisession disk. You'd think it would be just one, but it really doesn't matter if there is one or two saved sessions at that point. Either way works.
In other words, if the only cheap disks you can get are write-once disks and you don't mind making a few coasters until you figure it out, then use write-once disks instead of rewritable disks.

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#43 Post by Disco Makberto »

I think I got it now, Flash! Trying to explain the situation as I see it, let's say that I boot up with a multisession DVD+RW; then, if I burn the base ISO (same used on the multisession DVD+RW) with Burniso2CD, everything on the DVD+RW prior to burning the ISO is deleted; from that point on, I can choose to save the desktop to end up with a multisesssion DVD+RW so as to "defragment" the disc, or I can choose to not save anything to end up with a normal non-multisession DVD+RW (which is just the base ISO with nothing else). Am I correct?

Yes, I understand the issue of coasters. I will probably stick with my DVD+R's, though it doesn't hurt to experiment if I find some cheap DVD+RW's. I will revisit my local dollar store.

Carlos Albert
D-Mak

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#44 Post by Flash »

You're mostly correct. Burniso2cd will overwrite what's on a rewritable disk, but only as much of it as the iso will cover. Burniso2cd doesn't erase the rest of the stuff that might be on the disk. I found this out the hard way when I made an exact copy of a multisession Puppy that Burniso2cd had made of a used DVD-RW. The exact copy of what should have been about a 200 MB multisession Puppy filled a whole DVD! Turned out, I'd used a rewritable DVD that had been filled with a movie or something, so the whole disk was filled. :lol:
Thank goodness this didn't make any difference when it came to using the Puppy that Burniso2cd had burned onto the DVD-RW. All the stuff on the disk past the end of the iso was ignored.

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#45 Post by Disco Makberto »

Flash, I am bit confused, but I am tryng to figure out what's behind. To begin with, as it pertains to your "old DVD-RW" with a previous movie on it, did you record that movie with Burniso2CD or did you use something else?

Carlos Albert
D-Mak

hamoudoudou

last Puppy able to save cd multissession. ..

#46 Post by hamoudoudou »

a question posted somewhere is what is the last Puppy able to save cd .multissession. ..

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tallboy
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#47 Post by tallboy »

I asked, and did not get any good answer...
I also have a problem with a multisession CD that is locked after the first save, and I am not good enough to interpret the code in /usr/sbin/savesession-dvd to find the culprit.
True freedom is a live Puppy on a multisession CD/DVD.

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Flash
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#48 Post by Flash »

What do you mean, locked?

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tallboy
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#49 Post by tallboy »

The CD will not accept another save, because the multisession function is locked. It should remain open after each session is saved, but a codeline somewhere locks it. Where, I don't know.
True freedom is a live Puppy on a multisession CD/DVD.

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Flash
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#50 Post by Flash »

That's never happened to me. Which Puppy and how many sessions were saved on the CD?

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