Re: [Bacula-users] Multiplexing multiple jobs to tape

[Chris H. <chr...@ch...>]

Hi,

John Drescher wrote:

> You are on a gigabit network?

Yes.

> And the bacula-sd device (machine
> connected to the tape drive) is a fast machine with 2 or more
> processors and at least 2GB of memory? And you are using postgresql or
> mysql for your database? And you had software compression off?

At the moment bacula-director, bacula-sd and the catalog are on a dual 
Opteron with 1 gig of RAM. This isn't the final system it will be 
attached to, that is currently running our old backup system. So while 
it is a pretty old and crap machine, it was the best box that I could 
temporarily pull to give bacula a go on - the SAS controller we have is 
PCI-X, but the risers in most of our servers are PCI or PCI-E, 
seemingly, which severely limits my choice :(

bacula-fd was on a dual core 3.2GHz Pentium D with 4GB RAM, connected 
via a GigE switch. I did the testing while the load on the network was 
minimal. (e.g. at 2am while I was suffering insomnia :)

I may be able to steal use a Core 2 Quad with 4 GB to give that a go for 
a bit....

> Also I would test the raw drive speed of your tape drive / controller setup.
> 
> Put a blank tape in the drive and use dd to dump bytes to the device.
> When I first tested my LTO2 archive I did something like
> 
> dd if=/dev/sda of=/dev/nst0 bs=1M
> 
> and I got around 35MB/s.

Sure, that's the first thing I did when I got the drive ;)

I got 80MB/s, admittedly still some way off the supposed 120MB/s.

> To achive 120MB/s you will have to do that from a raid(0,5,6).

Sure.