During our last meeting, we did not have enough time to address all items on our agenda, so I'm creating a bunch of threads where we can start discussing some of the topics that we missed, so that we may have a smoother meeting next time, and can actually address current spins and spin review requests.
This thread concerns the 4GiB squashfs filesize limit, which will cause the DVD .iso file to be over 4GiB as well.
There's one basic argument to make against a DVD .iso file being over 4GiB, and that is that users downloading the DVD .iso file to a vfat filesystem cannot go over the magic 4GB filesize limit.
Note that it really is the .iso file size we're talking about, and we really don't care about the >4GB squashfs image; it just so happens that if the contents of a .iso go >4GB, the .iso will go >4GB ;-)
This particular issue is raised by the Games Spin, which I consider one of the first downloads for a Windows user who may or may not be using vfat still. Lots of (Windows) people want to see what Games are available on Linux, right? A relatively greater portion of these Windows users (then say, Linux users) may still be using vfat, and that's what I'm concerned with.
Also note that our x86_64 installation DVD is oversized in this aspect as well.
I wanted to vote on this during our last meeting. Either we block >4GB spins, or we allow them. So, the vote becomes: Do we allow .iso files over 4GB?
Please allow for a discussion if necessary, and then vote, so you do not have to change your vote after someone made you change your opinion ;-)
Kind regards,
Jeroen van Meeuwen -kanarip
On Wed, Jan 21, 2009 at 12:12:09 +0100, Jeroen van Meeuwen kanarip@kanarip.com wrote:
There's one basic argument to make against a DVD .iso file being over 4GiB, and that is that users downloading the DVD .iso file to a vfat filesystem cannot go over the magic 4GB filesize limit.
Note that it really is the .iso file size we're talking about, and we really don't care about the >4GB squashfs image; it just so happens that if the contents of a .iso go >4GB, the .iso will go >4GB ;-)
I think this should have said if the squashfs image is over 4 GiB, then the iso will definitely be over 4 GiB.
This particular issue is raised by the Games Spin, which I consider one of the first downloads for a Windows user who may or may not be using vfat still. Lots of (Windows) people want to see what Games are available on Linux, right? A relatively greater portion of these Windows users (then say, Linux users) may still be using vfat, and that's what I'm concerned with.
Are there people that have a feel of what fraction of Windows users are using vfat for their C: drive?
I wanted to vote on this during our last meeting. Either we block >4GB spins, or we allow them. So, the vote becomes: Do we allow .iso files over 4GB?
I believe that this was just going to apply to published iso's. My understanding is that it would be possible to pubished kickstart files that will require more space.
With the change to livecd-tools now in rawhide, it will be possible for the squashfs file system to be over 4 GiB (by using udf instead of iso9660 for the iso image). Most common DVD burning formats allow at least 4.7GB to be put a the DVD. This would allow about another 300MB to be added to an iso image (over the current limit) and still have it fit on a DVD.
For the games spin in particular exceeding the 4 GiB limit has benefits. I need to either cut a single large game that probably is a good example of what can be done on Fedora, several smaller games, or a good chunk of the desktop add ons over the base image.
Its hard for me to judge the trade off as I don't know how common vfat is for Windows users system drives. And the subset of users prone to trying Fedora iso's may not be representative of all Windows users.
USB flash drives are typically formated with vfat, but I don't think people are likely to download directly to a USB drive and if they want a portal way to move around a DVD image, the expected way to do that is on a DVD.
Bruno Wolff III wrote:
On Wed, Jan 21, 2009 at 12:12:09 +0100, Jeroen van Meeuwen kanarip@kanarip.com wrote:
Note that it really is the .iso file size we're talking about, and we really don't care about the >4GB squashfs image; it just so happens that if the contents of a .iso go >4GB, the .iso will go >4GB ;-)
I think this should have said if the squashfs image is over 4 GiB, then the iso will definitely be over 4 GiB.
Yes, it should have said exactly that ;-)
This particular issue is raised by the Games Spin, which I consider one of the first downloads for a Windows user who may or may not be using vfat still. Lots of (Windows) people want to see what Games are available on Linux, right? A relatively greater portion of these Windows users (then say, Linux users) may still be using vfat, and that's what I'm concerned with.
Are there people that have a feel of what fraction of Windows users are using vfat for their C: drive?
I wanted to vote on this during our last meeting. Either we block >4GB spins, or we allow them. So, the vote becomes: Do we allow .iso files over 4GB?
I believe that this was just going to apply to published iso's. My understanding is that it would be possible to pubished kickstart files that will require more space.
Yes, the question is what the Fedora Project wants to release officially.
With the change to livecd-tools now in rawhide, it will be possible for the squashfs file system to be over 4 GiB (by using udf instead of iso9660 for the iso image). Most common DVD burning formats allow at least 4.7GB to be put a the DVD. This would allow about another 300MB to be added to an iso image (over the current limit) and still have it fit on a DVD.
For the games spin in particular exceeding the 4 GiB limit has benefits. I need to either cut a single large game that probably is a good example of what can be done on Fedora, several smaller games, or a good chunk of the desktop add ons over the base image.
Its hard for me to judge the trade off as I don't know how common vfat is for Windows users system drives. And the subset of users prone to trying Fedora iso's may not be representative of all Windows users.
USB flash drives are typically formated with vfat, but I don't think people are likely to download directly to a USB drive and if they want a portal way to move around a DVD image, the expected way to do that is on a DVD.
LiveUSB however is going to have the squashfs on the USB stick, probably on vfat. I think this is an additional consideration we should make regarding a general guideline of <= 4GB spins or > 4GB spins.
Kind regards,
Jeroen van Meeuwen -kanarip
On Thu, Jan 22, 2009 at 16:50:38 +0100, Jeroen van Meeuwen kanarip@kanarip.com wrote:
LiveUSB however is going to have the squashfs on the USB stick, probably on vfat. I think this is an additional consideration we should make regarding a general guideline of <= 4GB spins or > 4GB spins.
Reformatting USB drives is a lot less of an issue than trying to get windows users to switch their system disks from vfat to ntfs. If a drive doesn't need to be read under windows it can be reformatted as ext[2-4] and there won't be a problem.
If the drive does need to be readable by windows, so that files can easily be copied to and from host systems, there are a couple of possible solutions.
One is to put more than one partition on the drive. Ext[2-4] can be used for grub and possibly the rest of the liveusb stuff and vfat or ntfs can be used for another partition. I don't know what the support for multiple partitions on usb drives is (I don't want to reformat mine right now to test it out), but I expect it to work at least under linux.
Another possible solution is to use a single ntfs partition. Grub can specify file locations by block numbers, so in theory it should be possible to tell grub where to read the grub.conf file. This is fragile, but I don't think people do a lot of hand editing of grub.conf on live usb drives. If kernel updates are being done using overlays, then some extra work will probably be needed to relocate the updated grub.conf file.