The need for initialising disks before use?

Sat Aug 19 04:15:04 UTC 2006

On Fri, Aug 18, 2006 at 09:52:02PM -0500, Brooks Davis wrote:
> On Fri, Aug 18, 2006 at 01:41:27PM -1000, Antony Mawer wrote:
> > On 18/08/2006 4:29 AM, Brooks Davis wrote:
> > >On Fri, Aug 18, 2006 at 09:19:04AM -0500, Kirk Strauser wrote:
> > >>On Thursday 17 August 2006 8:35 am, Antony Mawer wrote:
> > >>
> > >>>A quick question - is it recommended to initialise disks before using
> > >>>them to allow the disks to map out any "bad spots" early on?
> > >>Note: if you once you actually start seeing bad sectors, the drive is 
> > >>almost dead.  A drive can remap a pretty large number internally, but 
> > >>once that pool is exhausted (and the number of errors is still growing 
> > >>exponentially), there's not a lot of life left.
> > >
> > >There are some exceptions to this.  The drive can not remap a sector
> > >which failes to read.  You must perform a write to cause the remap to
> > >occur.  If you get a hard write failure it's gameover, but read failures
> > >aren't necessicary a sign the disk is hopeless.  For example, the drive
> > >I've had in my laptop for most of the last year developed a three sector[0]
> > >error within a week or so of arrival.  After dd'ing zeros over the
> > >problem sectors the problem sectors I've had no problems.
> > 

> > This is what prompted it -- I've been seeing lots of drives that are 
> > showing up with huge numbers of read errors - for instance:
> > 
> > >Aug 19 04:02:27 server kernel: ad0: FAILURE - READ_DMA 
> > >status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=66293984
> > >Aug 19 04:02:27 server kernel: 
> > >g_vfs_done():ad0s1f[READ(offset=30796791808, length=16384)]error = 5
> > >Aug 19 04:02:31 server kernel: ad0: FAILURE - READ_DMA 
> > >status=51<READY,DSC,ERROR> error=40<UNCORRECTABLE> LBA=47702304

i have recently managed to borrow an acer pentium III 550 mhz based
machine to  test and use as an installation server for freebsd
v6.1-release.

after running a minimum (basic) installation on teh machine, which has
a pair of drives (an 850 mb maxtor atapi/ide and a 1 gb fujitus
atapi/ide drive that has a block of some 400-550 megabite that the
bios/ms windows 2000 was not able to accessand i built my freebsd
partitions/slices around .. this is why i was originally interested in
this thread, so that i might get a way of refresh this disks media and
possibly revover teh who media surface or find out what is going on. 

originally the error messages concerned only the oddly
partitioned/sliced fujitsu but afte a few days it spread and as best as
i can recall the machine will loose console access (and network login
access as well but this could be some intermitent aspect) via sshd as
soon as either of the disks are written too, in my case it seems to be
access to teh swap slice as this machine has a small memory footprint,
32 megabyte untill i can canabalise another or replace the machine.

i cannot use freebsd 6.1-release on any of my machines as they all have
scsi drives and host with bootable cdroms but with bioses that use the
old (high seirra) bootable cdrom format, software and this machine
while not recent is still some 5 to 10 years newer than my own most
recent hardware.

stuff trimmed for brevity

> > I have /var/log/messages flooded with incidents of these "FAILURE - 
> > READ_DMA" messages. I've seen it on more than one machine with 
> > relatively "young" drives.
> > 
> > I'm trying to determining of running a dd if=/dev/zero over the whole 
> > drive prior to use will help reduce the incidence of this, or if it is 
> > likely that these are developing after the initial install, in which 
> > case this will make negligible difference...
> 
> I really don't know.  The only way I can think of to find out is to own
> a large number of machine and perform an experiment.  We (the general
> computing public) don't have the kind of models needed to really say
> anything definitive.  Drive are too darn opaque.
> 
> > Once I do start seeing these, is there an easy way to:
> > 
> >     a) determine what file/directory entry might be affected?
> 
> Not easily, but this question has been asked and answered on the mailing
> lists recently (I don't remember the answer, but I think there were some
> ports that can help).

might i add that while the original question (the refreshing of the
operating diskes media) has (may have) been answered, sorry i didn't
follow this thread as asidiously as i should have, because the thread
was only of partial interst to me, but since this post has caught my
interest because my installation of freebsd on stable hardware has
started to produce similare error messages i now think that the
original question has morphed (as these things usually do, somewhat
sadly) into something dare i say it, quiet different.

i've sent Mr Mawer a post off list giving some details and depending on
teh answers it might be worth while posting a bug report of sorts ???

most kind regards

jonathan

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