Dmitry,

> Tuesday, October 8, 2013, 2:37:57 PM, you wrote:
>
> KR> Working with FB 2.5 on Windows 64 bit, how does Nbackup level 0
> KR> perform compared to a high-performance copy utility like FastCopy?
>
> as I see on my desktop nbackup -b 0 is 2-3 times slower than lock/file
> copy/unlock. I think this is known behavior.

In general this is expected, though, the performance difference is less significant for larger databases, where the size of the database is larger than the OS disk cache. (OS's perform file copy using their caches to act as a write buffer for copy operations)

Nbackup will always be slower due to the fact that it performs individual page read/write (ie. Random IO) operations whereas file/fast copy operation use file block (ie. Sequential IO) operations which are much faster.

> KR> I'm asking because my DB is 80+ Gbyte and both the database and the
> KR> backup are currently on the same physical disk.
> this is BAD. Because of 2 concurrent operations - read and write.
> If this is not raid 10, then read+write will be 2 times slower than read from
> one physical disk and write to another physical disk.
> This has nothing related to nbackup, it is just about copying any file.

Agreed.


Sean