MBG wiki: Editing revision 23 of Backup, backup, backup ... using the server's DVD

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Read first the [[Backup, backup, backup ...]] section, then come back.

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You can only use the server's DVD writer if you are logged on the server. To do that use /ssh server/ from the machine you work from (and then use your password to login). The files to be backed-up must be on server's disk. If your data are inside the /work directory, fear not : the /work directory is accessible on the server's /tmp. To make this clear : if the directory /work/myself/2backup contains the data you want to back-up, then do (after logging-in to server) cd /tmp/myself and you should see your files and directories.

* You should never try to back-up data from the /work directory. Always access the data /via/ server's /tmp directory.

* Do not use DVD+R disks. What you need is DVD-R disks. Double-layer disks have not been tried, and it is not known whether they can safely be used for back-up.

== Preparing a 'closed' (not multisession) DVD ==

<code>
sudo growisofs -Z /dev/scd1 -R -J -udf <files>
</code>

where /files/ can be a single file (say, a tar archive), or the name of a directory.

Be careful : Single layer DVDs can fit a maximum of 4,700,000,000 bytes (~4.4 GBytes). /BUT/, no single file can be larger than exactly 4 GBytes (4,294,967,296 bytes). If you want to write a file which is larger than 4 GBytes you will have to split it (using for example /split/, or in the case of DCD files, /catdcd/).

To confirm that everything has been written correctly :

<code>
mount /mnt/dvd
cd /mnt/dvd
diff <file1> /tmp/mydir/<file1>
diff -r <dir1> /tmp/mydir/<dir1>
</code>

== Preparing a multisession DVD ==

NOTE WELL : No file should be larger than 2 GBytes

For the first session (the first time you write something) use :

<code>
sudo growisofs -Z /dev/scd1 -R -J <files>
</code>

where /files/ can be a single file (say, a tar archive), or the name of a directory.

For all the other sessions, use :

<code>
sudo growisofs -M /dev/scd1 -R -J <files>
</code>

To confirm that everything has been written correctly :

<code>
mount /mnt/cdrom1
cd /mnt/cdrom1
diff <file1> /tmp/mydir/<file1>
diff -r <dir1> /tmp/mydir/<dir1>
</code>

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