hard disk integrity check
alan at linuxholdings.co.za
Wed Apr 19 13:49:45 UTC 2006
On Wednesday 19 April 2006 14:15, Balvinder Kataora wrote:
> > SMART catches about 80% of looming disk errors (according to the
> > SMART people that is). And disk firmware is written to take care
> > of usual errors wherever possible, but it'll never be
> > bullet-proof.
> I never knew that about SMART.
A quick conceptual overview of SMART:
Disks fail mostly for mechanical reasons, and the process is
well-understood. Motors and bearings wear out, the servos moving the
head in and out develop play, that kind of thing. Manufacturers have
huge amounts of data by now on how drives behave as they age, for
example a very good indicator is spin-up time - how long it takes the
drive to get up to speed from a standing start. Statistical analysis
of all this data shows that when a drive starts to take longer than X
amount of time to get up to speed then the odds of it failing within
Y hours becomes Z%, so predictions are possible.
What SMART can't tell you anything about is electronic failures. These
tend to happen without warning, or with no discernible pattern
beforehand. Lucky for us, they are relatively rare compared to
> This 20Gb drive will be used as an OS disk or to boot the machine
> from. The main user data will be kept on a RAID5 array. Looking at
> the machine I have it seems a RAID1 Mirror set is possible for the
> boot disk. I have little (close to none) long term experience with
> mirrored boot disk, do you think the time invested to create one
> would be beneficial?
I take the view that it depends on your needs. If the machine is
running a Space Shuttle and absolutely cannot ever fail for any
reason, then you'd be wise to figure out how to do it. For regular
use with a good admin nearby and especially if you have a spare drive
anyway, it's hard to justify the effort. But that's my view, others
If only you and dead people understand hex,
how many people understand hex?
alan at linuxholdings dot co dot za
+27 82, double three seven, one nine three five
More information about the ubuntu-users