Leslie Rhorer wrote:
Leslie> I may have to rethink my position on using raw drives. If I
Leslie> partition the drives, I can make the partition a bit smaller
Leslie> than the whole drive, allowing for the addition of a future
Leslie> drive whose size is a bit off. I hate to waste space, but being
Leslie> stuck with an undersized or limping array is worse.
This is not nearly as big a problem as it used to be. Drive
manufacturers need to adhere to an IDEMA standard which requires them to
use a specific LBA count for each capacity class.
I.e. a 500GB Seagate drive must have exactly the same number of sectors
as a 500GB Western Digital or Hitachi.
The IDEMA LBA standard applies to 3.5" form factor drives over 160GB as
well as 2.5" FF drives over 80 GB.
Is that realy exactly so many LBA sectors or at least as many?
I don't really see anything wrong with a 500G drive having a few more
sectors. And I know my Maxtor 200G disk is 3G bigger than Seagates.
'Excellent point. If the spec calls for a minimum of sectors, then
it is quite possible a complaint drive might well have fewer sectors than
the ones I used to build the array. OTOH, all of the 1T drives on my
systems have precisely the same number of user available sectors, and all
the 1.5T drives have the same number. Since the drives represent not only
different models from one manufacturer but also different manufacturers,
this suggests to me an adherence to a specific spec. On yet the other hand,
it may merely mean they all have the same number of platters and similar
architectures. The 1.5T drives are less than 1.5 times bigger than the 1T
drives, so I could not replace a 3 drive 1T triplet with a pair of 1.5T
drives.
That last sentence is important! If this is a standard, then it would
seem to be actually intended to deceive the consumer. If there is to be
a standard for 1, 1.5, and 2, they really should have some sensible
relationship in size.
That said, I confess that I use partitions and leave a little breathing
room on my drives when building a raid array.
--
Bill Davidsen <davidsen@xxxxxxx>
Obscure bug of 2004: BASH BUFFER OVERFLOW - if bash is being run by a
normal user and is setuid root, with the "vi" line edit mode selected,
and the character set is "big5," an off-by-one error occurs during
wildcard (glob) expansion.
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