I have the feeling that my problem is actually linked to a corruption of a mySQL table, due to an electrical power shutdown (that actually occurred yesterday, just before the problems started).
If I try to connect to mysql, I get the following message:
# mysql ERROR 2002 (HY000): Can t connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
A similar issue can be found in this discussion.
I found that my corrupted table is this one:
# myisamchk -a *.MYI | grep error /var/lib/mysql/mysql/#sql-3e94_1.MYI
Any idea to fix/investigate the issue?