low-level format before install?

[Chuck Swiger]

On Apr 7, 2009, at 12:15 PM, John Almberg wrote:
> Well, I've got real problems with that database server that lost  
> power over the weekend. We reloaded FreeBSD from scratch and then  
> reinstalled mysql, and pf. I loaded up my database and switched over  
> all my customer's websites. The database server ran fine for about 2  
> minutes, and then died. At the moment, I can't even ssh into the  
> machine, although they can get into it using a keyboard/monitor at  
> the data center. In other words, sshd is not working.

That sounds like either a hardware problem (ie CPU overheating or  
marginal PSU failing under production load), or less likely, some kind  
of software misconfiguration.  System logs would be useful to see  
whether any signs of trouble are being mentioned.

> I am now wondering what kind of format the FreeBSD install process  
> does by default, and if it is possible to do a low level format,  
> first, to block out any bad sectors (not sure if this is the right  
> terminology).
>
> I'm starting to get real depressed about this machine... You would  
> think a top-tier data center could keep the power on...

SCSI drives support a standard mechanism called "format unit" to do a  
low-level format; ATA and SATA drives do not have a standard  
mechanism, but you might be able to find a utility from the  
manufacturer which can do such a thing.  It would not be expected that  
doing such would be helpful, as any modern drive has automatic  
mechanisms to replace bad sectors with spares transparently, at least  
until the drive has gotten to such a condition that it's out of spare  
sectors (in which case the entire drive is likely to be toast soon,  
anyway, and should be replaced ASAP).

However, if you do suspect drive problems, try installing and running  
smartctl from /usr/ports/sysutils/smartmontools, and do a self-test or  
two.

Regards,
-- 
-Chuck