[Samba] Samba enterprise performance?

[Greg Freemyer]

On 2/6/07, Koen Smeets <samba at fotoloog.org> wrote:
<snip>

> I was thinking RAID6 Areca cards (2 GB of NVRAM/BBU), quad Xeon servers with 16
> GB of RAM and 'enterprise' sata disks (though possibly avoid raptors due to
> relatively low capacity).

For those people reading this who suddenly think they need to run and
and get some Enterprise SATA disks:

Interesting term 'enterprise' sata disks.   The implication is that
they are in some way higher quality than standard sata disks.

IIUC, this is not true.  In fact for desktop or non-RAID use it is
actually the reverse.

Standard (non-enterprise) SATA disks place reliability as a primary
concern.  enterprise sata disks place consistent response time as a
primary concern.

This comes into play when there are media issues and crc errors are
being experienced trying to read the data from disk.

With the standard "desktop" firmware retry logic in the drive
electronics is invoked to in effort to minimize data loss.  This retry
logic can take up to 7 or 8 seconds AIUI.

With the enterprise firmware, there is no retry logic.  As soon as a
crc error occurs at the drive head level, the read is failed back to
the Sata controller.  The expectation is that the system has RAID
redundancy built in and that the data can be retrieved quicker from
the other disks than from the disk experiencing read issues.  This
also allows better tracking of drive tracking at the system level.

As I said, seems like an interesting definition of enterprise to me.

Greg
-- 
Greg Freemyer
The Norcross Group
Forensics for the 21st Century