Re: S.M.A.R.T. hard drives WAS: SCSI vs. IDE performance test

[sNip]
>> I used smartsuite (http://sourceforge.net/projects/smartsuite/) to view
>> the status of the drives, but the relocated sector count appears only 
>> available on ide drives.  Does anyone know if that is the nature of
>> scsi drives or is it just a limitation of that tool?
> 
> Do SCSI drives even do relocation?  I had a Seagate SCSI drive that
> would beep every time I tried to access a bad block, basically telling
> me to replace the drive.

    	Normally this should be handled by the OS since a judgement can be 
made on data reliability whereas the hard drive wouldn't know which 
algorithm to use (e.g., CRC, etc.).

    	Perhaps the following would be "food for thought" on future table 
space implementation so as to do something that Oracle hasn't thought of...

    	On NetWare v2.x (c. 1980) through v6.5 (the current version, released 
in 2003) a section of each Partition was designated as a "HotFix" area (the 
percentage is configurable at the time of formatting) which is 
automatically used in place of bad blocks as they are discovered, and error 
messages are generated in system logs and on the System Console whenever 
one is found.

    	The default percentage originally started out at 2% but has eventually 
be lowered to 0.2% over time due to a number of factors including the 
following:

    	    	1. Larger capacity hard drives; and,

    	    	2. Fewer defects on new hard drives -- in the old days (20 years 
ago definitely qualifies as "old days" in the computer industry) it was 
common for new hard drives to come with errors on the drive, but now all 
hard drives come with zero bad sectors (I assume this is due to improved 
techniques and practices at the manufacturing level).

    	I'd be quite happy to write the documentation explaining table spaces 
in PostgreSQL should it become a feature in a future release.  In fact, I 
would really enjoy doing this, and so I believe that my contribution could 
be very helpful.

-- 
Randolf Richardson - rr@8x.ca
Vancouver, British Columbia, Canada

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