We run a big share of Xen virtual servers spanned over multiple servers and if you want to use the full or best capability of Xen, I would suggest LVM (Logical Volume Manager), it makes life a lot easier, especially for those who do not run a RAID setup (We run RAID10 on all VM nodes) as you can split the partition over multiple hard drives. I’m not going to cover setting up the LVM as there are loads of tutorials on how to do that but I will rather cover the best way to migrate a LVM volume.
I have recently had reason to convert an Access MDB file to CSV for use in a mysql database. I don't like the idea of an Access database on a production server and Microsoft has been agreeing since 1999.
As it turns out it is actually very easy, there is GPL software available for the job at http://mdbtools.sourceforge.net/. If you are using Ubuntu or Debian you can use apt-get install the mdbtools package.
To get the list of tables, you run the following command:
mdb-tables database.mdb
You can then get a CSV version for each table using:
mdb-export database.mdb table_name
You can also convert the mdb into a format required by MySQL. First you must get the put the table schema into the database using the following command:
mdb-schema database.mdb | mysql -u username -p database_name
You then import each table by running:
mdb-export -I database.mdb table_name | sed -e 's/)$/)\;/' | mysql -u username -p database_name
Sed is required as mdb-export doesn't put a semi-colon at the end of each insert statement, which MySQL definately doesn't like.
After running this, you can now be rid of the horror that are Access MDB files :)
Dieser Artikel beschreibt, wie man das Energiemesssystem EM 1000 mit einem EM 1000-WZ Strommesssensor unter Debian einrichtet und die Messwerte mit Hilfe von Cacti darstellt.
current power graph
Zum Betrieb wird das “ftdi_sio” Kernel Modul benötigt. Bevor man es einsetzen kann werden jedoch die “vendor” und “product” IDs benötigt.
Traditionally, booting an Ubuntu installation with the root filesystem on a degraded RAID drops the system into a busybox prompt in the initramfs.
This is a very conservative approach, allowing the system administrator to consciously recognize that the system has lost a RAID disk, and preventing the system from booting into an unprotected situation.
How to restore Grub from a live Ubuntu cd.
This will restore grub if you already had grub installed but lost it to a windows install or some other occurence that erased/changed your MBR so that grub no longer appears at start up or it returns an error.
You can extract sound from a DVD, one track at a time or a chapter at a time. Some simple command line examples should suffice to demonstrate how this is done.