I have recently installed Debian 8.1 onto my hard disk with an iso image burned to DVD-r. I was trying to install g++ from the terminal when it asked me to insert the dvd from which I installed the OS onto my hard disk before continuing. This, being my first concern, raises my second concern even more. But more detail on the first concern; it didn't work. I inserted the cd, and it gave me a very large error message. I tried apt-get update, but it gave me the same error. I get this error whenever I try to install anything with apt-get install and put in the dvd as it asks. That error is:
Reading package lists... Done Building dependency tree
Reading state information... Done The following extra packages will be installed: binutils g++-4.9 gcc gcc-4.9 libasan1 libatomic1 libc-dev-bin libc6-dev libcilkrts5 libgcc-4.9-dev libitm1 liblsan0 libstdc++-4.9-dev libtsan0 libubsan0 linux-libc-dev manpages-dev Suggested packages: binutils-doc g++-multilib g++-4.9-multilib gcc-4.9-doc libstdc++6-4.9-dbg gcc-multilib make autoconf automake libtool flex bison gdb gcc-doc gcc-4.9-multilib gcc-4.9-locales libgcc1-dbg libgomp1-dbg libitm1-dbg libatomic1-dbg libasan1-dbg liblsan0-dbg libtsan0-dbg libubsan0-dbg libcilkrts5-dbg libquadmath0-dbg glibc-doc libstdc++-4.9-doc The following NEW packages will be installed: binutils g++ g++-4.9 gcc gcc-4.9 libasan1 libatomic1 libc-dev-bin libc6-dev libcilkrts5 libgcc-4.9-dev libitm1 liblsan0 libstdc++-4.9-dev libtsan0 libubsan0 linux-libc-dev manpages-dev 0 upgraded, 18 newly installed, 0 to remove and 92 not upgraded. Need to get 1,008 kB/39.2 MB of archives. After this operation, 116 MB of additional disk space will be used. Do you want to continue? [Y/n] y Get:1 http://security.debian.org/ jessie/updates/main linux-libc-dev amd64 3.16.7-ckt20-1+deb8u3 [1,008 kB] Err cdrom://[Debian GNU/Linux 8.2.0 Jessie - Official amd64 DVD Binary-1 20150906-11:13]/ jessie/main manpages-dev all 3.74-1 Read error - read (5: Input/output error) Fetched 1,008 kB in 11s (85.8 kB/s)
E: Failed to fetch cdrom://[Debian GNU/Linux 8.2.0 Jessie - Official amd64 DVD Binary-1 20150906-11:13]/pool/main/b/binutils/binutils_2.25-5_amd64.deb Hash Sum mismatch
E: Failed to fetch cdrom://[Debian GNU/Linux 8.2.0 Jessie - Official amd64 DVD Binary-1 20150906-11:13]/pool/main/m/manpages/manpages-dev_3.74-1_all.deb Read error - read (5: Input/output error)
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
My second concern, seeing as this whole dvd thing happened, is whether or not I can actually boot into Debian after shutting off my computer without the DVD in. Will that work? Will it automatically boot into Debian if I shut off my computer and turn it back on? I'm afraid to turn off my computer because my god did I struggle to get this working on my laptop in the first place (Lenovo is not GNU/Linux friendly).