The need for initialising disks before use?

[Frode Nordahl]

On 17. aug. 2006, at 15.35, Antony Mawer wrote:

> Hi list,
>
> A quick question - is it recommended to initialise disks before  
> using them to allow the disks to map out any "bad spots" early on?  
> I've seen some "uninitialised" disks (ie. new disks, thrown into a  
> machine, newfs'd) start to show read errors within a few months of  
> deployment, which I thought one or two might seem okay, but on a  
> number of machines is more than a coincidence...
>
> Is it recommended/required to do something like:
>
>     dd if=/dev/zero of=/dev/ad0 bs=1m
>
> before use to ensure the drive's sector remappings are all in  
> place, before then doing a newfs?
>
> FWIW, I've been seeing this on more 6.0 systems that I would have  
> thought to be just chance...

I think the change is that more systems use cheaper SATA drives now.

On several occations I have been unable to build a RAID (hardware or  
software based) on brand new disks due to one of the drives "failing"  
during initialization.

After zeroing all the drives with dd, everything works fine.

I'm not sure if vendors cut corners on initially formatting their  
drives to save some $$ or if SATA just lacks some features over SCSI  
that causes trouble like this.

--
Frode Nordahl