On Thu, Apr 16, 2015 at 4:13 PM, Moez Roy <moez.roy(a)gmail.com> wrote:
> Copying more than 500 MB crashes Fedora Live CD even though there is
> sufficient RAM.
> It doesn't matter how much RAM your system has, once you copy more
> than 500 MB you will get stuff like "Input/output error" or just plain
> crashes like "Segmentation fault".
> Why does this happen?
I think I figured out why this happens.
The file /usr/lib/dracut/modules.d/90dmsquash-live/dmsquash-live-root.sh
seems to create a 500MB overlay:
dd if=/dev/null of=/overlay bs=1024 count=1 seek=$((512*1024))
if [ -n "$setup" -a -n "$readonly_overlay" ]; then
RO_OVERLAY_LOOPDEV=$( losetup -f )
losetup $RO_OVERLAY_LOOPDEV /overlay
losetup $OVERLAY_LOOPDEV /overlay
Wouldn't it be more efficient if this was tmpfs instead?
This also affects installing applications in the live environment
where the installed size is more than 500MB.
Hello everyone - I am trying to find out what the numbers represent in the
output of a "dmsetup status" command on a LiveCD:
[root@localhost ~]# dmsetup status
live-osimg-min: 0 4194304 snapshot *1272/1272 16*
live-rw: 0 4194304 snapshot *7568/1048576 40*
I've asked a Superuser question
but it doesn't seem to be getting any activity. The man pages for dmsetup
only talk about the "--target" option and don't talk about explicit labels
for the numbers - does anyone know what they are?
I'm especially interested in the bottom far right numbers, the 7568 /
1048576 - that's about a gibabyte and my LiveCD remounts itself read only
as soon as those numbers meet. The smaller value seems to tick up much
faster when there are reads and writes to the root filesystem.
Can anyone help? Is there a way to increase it from a gibabyte up to
something more reasonable to keep my LiveCD from hanging itself every time
I copy files in or out?
I maintain foreman-discovery-image project which aims to be minimal
fedora/centos-based image that enables bare-metal hardware provisioning
via PXE/TFTP by uploading facts and awaiting orders (reboot into
Anaconda after TFTP is set up for the particular machine).
So far I have been pretty successful with livecd-tools. Our image is
about 140 MB in size, but my goal is to bring this number even more
down because udp/TFTP is slow.
Is there any way to tell livecd-creator to create smaller disk image (by
default it is 1 GB). Our installation consumes about 350 MBs (unpacked),
therefore 512 MB could be good start. Not sure how much bytes I can save
with this, but I guess a few.
Do you think that tuning ext3/ext4 in the kickstart could save me some
extra bytes? I was thinking doing something like
or similar to minimize FS metadata. To be honest, I don't understand
documentation of kickstart in this regard. I am not sure if this is even
Another question is in regard to syslinux. Can I provide my own syslinux
configuration for my live media? I need to provide some extra kernel
parameters and the only option is perhaps to unpack, change and repack
the ISO image.
Many thanks with any tips. For now, my plan is to do some hacks on our
side (at least for the syslinux thing) and provide some patches if that
makes any sense upstream.
Lukas #lzap Zapletal