I have CentOS 5.3 installed on a cluster and am attempting to perform a tape backup of a file system. Dump is working and I have performed some dumps in the past. One of the filesystems requires a multi-volume dump. In the past, to speed up the dump process, I have used the "buffer" program to provide a buffer so that the tape drive remains busy. Doing this significantly speeds up the dumping procedure by a factor of 1.5 to 3. However, I've only used it on single volume dumps. At present I am using the following to perform the dump

% /sbin/dump -0 -L "/home Lvl 0" -u -z -f - /home | buffer > /dev/st0

On the filesystem where a multi-tape dump is needed I eventually get the following

DUMP: 44.24% done at 4614 kB/s, finished in 5:15
buffer (writer): write of data failed: No space left on device
bytes to write=10240, bytes written=-1, total written 44173750K
DUMP: Broken pipe
DUMP: The ENTIRE dump is aborted.

I assume that the end of the first tape is being reached and but dump doesn't know this because it is just sending the output to stdout and buffer doesn't know that it needs to wait for a new tape so that the dump can continue. Any ideas on how to perform a multivolume dump using the buffer as it really speeds up the process.

Buffer is not a CentOS program. Best to ask where you got it. Seems to be available from RPMforge.

Have a look at mbuffer, which is part of Fedora. The man page shows an example of how to handle a tape change. The source package rebuilds nicely for CentOS w/o issue last time I tried, which was version 20080507-3. Good luck!