Debian 6 squeeze to 7 wheezy
Debian release names have somehow too many "e" in the names, so I sometimes confuse them. But as debian 6 EOL is getting closer, it is time to upgrade to 7. Here is a few notes that may come handy.
GRUB
Update to grub2 is probably automatic, if you still have grub1 or grub2 only as an alternative, you should rather install grub2 package in squeeze, migrate configuration (should be done automatically) and start upgrade-grub-from-legacy before upgrade.
UUID
Switch your fstab to UUID, the wheezy installer will complain about it anyway. While /dev/sdX was working for many years, kernel devs have no other option than consider them not persistent - they do change on reboot with e.g. usb mass storage devices attached.iptables
iptables deprecates for a long time a structure
--option !
with
! --option
Be carefull to reformat your iptable rules before upgrade otherwise your iptables rules may not load.
E.g. this one I am not sure is the same thing.
--tcp-flags ! SYN,ACK,RST SYN
! --tcp-flags SYN,ACK,RST SYN
iptables version string
I am not sure about this, but it looks like the iptables version string was shorten from 30 to 29 chars only. Again this may prevent your iptables rules to load.
roundcube
Wheezy does not have a roundcube with sqlite support (roundcube is missing it). If you used sqlite prepare for the migration of roundcube settings saved in sqlite. I had a log of troubles with this as upgrade was complaining about
E: Could not perform immediate configuration on 'package'.
http://www.debian.org/releases/stable/i386/release-notes/ch-upgrading.en.html#immediate-configure
The advise in debian release notes did not help, I was not able to overcome this other way than uninstalling roundcube before upgrade. After upgrade install mysql-server, reinstall and reconfigure roundcube-core to set up mysql database. MIgrate the roundcube sqlite to mysql if necessary
https://wiki.debian.org/Roundcube/DeprecationOfSQLitev2
Aptitude
While aptitude is not a recommended tool for deb package management for some time, you may have it installed too. It looks to me like the dependencies have exploded in wheezy for aptitude. I may be wrong, but removing aptitude saved me 200MB of new space required.
Dovecot
Dovecot configuration changed completely. There is however good migration documentation, mostly it'll be enought to do doveconf -n.
rsyslod
Wheeze changed the logging daemon from syslogd to rsyslog. Rsyslog is able to "consume" same logging rules as syslogd, but there is no migration and rsyslog is only logging its "defaults" not reading old syslogd confs.
VLAN
It is not necessary any more to configure explicitly the VLANs in interfaces with pre-up, post-up and vconfig (it is probably also deprecated for some time, but in wheezy it will cause the VLANs to not be configured at all.
vsftpd
Wheezy vsftpd is so secure, it will not run with writeable user homes and directive chroot_local_user. It just prints
500 OOPS vsftpd: refusing to run with writable root inside chroot()you can either reformat your complete ftp directories to have separate two leves of subdirectories in user homes for ftp or you have to use a third party patched vsftpd.
http://blog.waja.info/2013/05/13/500-oops-vsftpd-refusing-to-run-with-writable-root-inside-chroot/
tigon3
Popular network ethernet card Broadcom Corporation NetXtreme BCM5721 Gigabit Ethernet PCI Expres needs a firmware-linux-non-free package from non-free repository to install a tg3 driver firmware. Non-free may not be a part of normal sources.list for apt.