Thanks Jos,

not the answer I wanted to hear but I now know where my slow performance is coming from.

How much did you save by going with a single controller configuration? Or alternatively, how much would it cost you to upgrade?

For your intended application I would think that the cost would be justifiable.

we're using it as a B2D target but really slow performance when writing data to disk.

But how much speed would we gain by adding an extra controller, is it worth the extra 2000 euro's.

"Would it be worth it?" is a good question.

"What would make it worth it?" is a reasonable reply to that question.

Or


How fast is is currently and how much faster would it have to be in order to justify the additional expense? If your backup windows could be shortened by a number of hours would that make a case for the expenditure?

I have an AX4-4F that I use as a backup target. It has 60 1TB drives in it and it connects to two Windows 2003 servers running Backup Exec (12.0 and 12.5 at the moment).

One workload that it handles is about 25 streams (concurrent backup jobs) that deliver a total of around 120MB/Sec to it.

I also de-stage some backups to tape (two LTO-4 drives) from one of the two servers, those run at a bit over 150MB/Sec combined.

I don't consider these highly optimized environments, but obviously your results may vary.


I have seen more than one person here who is disappointed with write performance for a single SP unit. Perhaps they were just catalog shoppers or something but I'd be concerned if someone was recommending single SP configurations for a backup-to-disk application.

It is $3,550.00 List price to upgrade to a dual controller.

We installed the extra SP, after enabling write-cache on controller and LUNs we had a happy customer again, doing 150MB/s.