Roger Williams wrote:

Having just added lots of disk space to a network of Linux workstations and 
servers, I
decided to take the plunge and check out Amanda as a replacement for a set of 
home-grown
dump scripts that I have been using for years. I am moving from SuperDLT and 
backing up
10s of GB to LTO4 and wanting to back up 100s of GB.

I have been very disappointed to discover that the performance of Linux dump 
seems to be
completely awful in recent RedHat Enterprise and CentOS releases.

Have other Amanda admins seen this?

My first test dump of a 160GB filesystem (with 'program "DUMP"' in amanda.conf) 
took
~10 hours. This is completely hopeless if I want to regularly back up at least 
4 times
that amount. The poor performance is nothing to do with Amanda. It seems that 
it is
dump itself in recent Linux, eg see

 http://bugzilla.kernel.org/show_bug.cgi?id=8636

As I have a number of machines with various distributions, I have run a few 
tests of a simple

 dump -0 -f /dev/null /filesystem

with various "large" filesystem sizes. The results are summarised below. Yes, 
dump performance
has tanked. On recent RHEL and CentOS it now runs at ~8000 kB/s or less. On 
older distributions
dump is much, much faster.

I am surprised that there seems to be no earlier mention of this issue on the 
list. Do all you
Amanda admins out there use GNUTAR in place of dump on Linux?

yes. Gnutar on Linux.

--
---------------

Chris Hoogendyk

-
  O__  ---- Systems Administrator
 c/ /'_ --- Biology & Geology Departments
(*) \(*) -- 140 Morrill Science Center

<hoogendyk AT bio.umass DOT edu>

Erdös 4