Having to make a live CD for a friend to use as a recovery disk.

So downloaded kubuntu 20.04 and wrote to DVD using K3B, then tested on my own machine -

1. kubuntu 20.04 took about 5 minutes before it got to the desktop. Once it was in it was quite responsive.
2. then did the same with Slackware Current that took over 6 minutes before it got to the desktop.

I then tried a Linux Format cover disk from December 2019 containing Xbuntu 19.10. Gave up after 15 minute all I got was just the Xubuntu logo indicating it was trying to boot.

I then tried kubuntu 20.04 in VirtualBox using my DVD reader. It took 4m18s to get to the desktop. Once I was in it was quite responsive.

I then tried kubuntu 20.04 in VirtualBox using the downloaded iso. It took 50s to get to the desktop. Quite reasonable I thought.

The system on the box I'm using is Slackware 14.2.

It's been a long time since I used the DVD reader to boot up a Linux live DVD, but I can't remember it taking this long to boot up and do some real work.

Is my memory playing tricks with me and all those years ago it really did take a long time to book a live DVD. Or have I got some tweaks to do to enable faster booting from a DVD?

Alex

It does seem too much, but I don't remember either.

You are absolutely sure you're burning a live disk, and not actually installing to that DVD?
What are the respective distros' instructions for creating a DVD?
Is your DVD player working otherwise? Tried some other (known to be working) DVDs? Is it making funny noises? Have you cleaned it?

The VM will almost always be way faster. Reading from a burned drive is always slow.

Booting to a DVD in the fastest possible way may need to have a number of things set correctly at boot time. Not knowing what hardware you have makes it difficult to guess. Generally the speeds that are set in and drivers used to access the drive.

I assume a long time ago the drive was a CD.

You might be able to vastly speed it up only if you can discover the speeds that are set in.

Might use different optical media. Best quality usually best. Always burn at the very slowest speeds. Always.

One could use a cd/dvd to boot to a networked source for reset of live media to be fastest.

Get new optical drive and or change how it connects to the machine. Some drives don't start off in fastest speed until the system is up.

I'm writing to Verbatum DVD-R 16X

I've tried writing on two different drives - one internal connected directly to the MotherBoard using a SATA cable, the other external and connected using a USB cable.

I've also tried writing using a laptop with it's internal drive.

Whatever I do it takes an age to boot from the DVD.

Found disk I created some time ago Lubuntu 17.10. This takes 2 minutes to boot. A lot faster than 5+ minutes for Kubuntu. Could it be that I'm looking at this through rose-tinted glasses and that Kubuntu is always going to take a lot longer to boot than Lubuntu.

I shall try Lubutu 20.04 and see how long that takes to boot.

I will post what happens.

Your situation isn't that unusual.

The ability of a disc to be read is affected by a number of issues.

One is how you burned the disc. Burn at the very slowest speeds always. The disc can't be trying to seek out blank spots.

Two is the boot driver settings that the reader is able to use.

Three is the read speed of the reader.

Four is the ram and cpu speeds along with the amount of ram available. Usually having a swap file ready to use may improve that loss.

The speed may be affected by 32/64 bit issue.

There can be more issues affecting this such as the window manager and general design of the live media.

It can't hurt to try a few things but I'd tell you to make a usb 3 flash drive to see if you can boot to it.

As someone who pretty consistently uses CD/DVD boot to setup new builds ('if it works...') - this is the kind of behavior I expect from external bus-powered USB drives, but quality, modern, internal SATA drives, assuming the host computer is also modern/fast, shouldn't be quite so sluggish (if I remember right, a lot of those slim-line drives usually top out at around 4x - most newer 5.25" drives can do at least 12x). I would say I agree with jefro's list - high quality burns in a good drive on a modern/fast computer with a lot of RAM is usually pretty clean, the further away you get from that, the worse it gets. I've seen the exact behavior you describe with Slackware 14.2 on el cheapo bus-powered drives on slower/older machines with 2-4GB of RAM - the installation itself also takes longer to complete. By contrast, throw that into a nice 16x SATA drive on an 8-core machine with 16-20GB of RAM and it flies.

Overall I tend not to worry about boot-up time in these contexts since this is usually a 'buy once cry once' kind of thing - it isn't like I'm re-installing the host OS of my machine every day, and for 'playing around' there is always VMs (which as you've observed are always much faster). I've found that decent quality USB thumb drives can improve this kind of performance in various points but aren't a panacea - startup is usually still worse than 'once the OS is already installed' performance, and some applications (on live CDs/USB) don't run as 'smoothly' as internal installation. Also consider the overall size of data you're asking the disc to read out - OSes (like everything else) have gained quite a bit of weight over time. And this isn't unique to Linux itself - I've watched similar trends with Windows and OS X, as well as various applications. Despite this, our expectations seem to often go in reverse: "I want it eventually" has become "I want it 90 seconds ago." (Note that this isn't an entirely unreasonable expectation either - 20 years ago my computer had 1 core and 512MB of RAM, 10 years later that was 4 cores and 4GB, and today its 32 cores and 32GB - 'faster' is an understatement at each jump and I do expect the machine to perform accordingly).

I think you got it.
Yes, Kubuntu 20.04 is much heavier than Lubuntu's older LXDE release.

I booted kubuntu 20.04 install DVD to command line it took 3minutes.

Logged on at command prompt and then ran startx

It took a further 1m 30s to get to the desktop.

I'll mark this as "solved" as I can't find anything wrong other than maybe me!

1 members found this post helpful.

Glad to hear it. Just FWIW: 3-4 minutes to desktop in a modern KDE-based distro from a DVD doesn't sound so unreasonable based on my limited experience with PCLinuxOS (which also uses KDE).