First...avoid to perform formal error using "b" instead of "B"

You speak about T(era)Byte or T(ibi)Byte and the B must be uppercase. Lorwercase b stands for bit…and this is a really huge difference J

 

Last I don’t think that, till we’ll speak about PB amounts of data, the difference could have a sense: the difference between using base 2 (2^10=1024) coming from the only 2 computer “fingers” (0 and 1) or base 10 (10^3=1000) coming from human being 10 fingers hands.

 

It’s already hard enough to let accounts and customers to understand the difference among raw and usable…

With a smile

;-)

 

Regards

 

 

Da: toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] Per conto di Fletcher Cocquyt
Inviato: venerd́ 11 gennaio 2013 23.56
A: toasters@teaparty.net Lists
Oggetto: When is 1Tb == 1000Gb == 1000^2Mb == 1000^3Kb == 1000^4bytes ?

 

This came up when I was doing some work with our new backup vendor's API, pulling out their backup numbers all reported in bytes and converting to Gb or Tb for our cacti graphs.

 

set bytes=7696581394432

echo $bytes bytes = `echo $bytes"/1024/1024/1024/1024" | bc` Tb

7696581394432 bytes = 7 Tb

 

But the numbers on the vendors dashboard were different.  I asked vendor support and the next day they confirmed (as I suspected) they were converting using powers of 10

But what I did not know, was this was on purpose due to the disk manufacturer's convention: http://en.wikipedia.org/wiki/Hard_disk_drive#Units

 

For someone with a computer science background this was surprising to not have uniform definitions of units across media

 

Ram manufacturers don't do this according to the article they use (do Flash or SSD makers?)

 

So if I have full 1Tb RAM drive and try to copy it to a 1Tb HDD, it won't fit - I'll need 9.95% more space due to the different definitions of Tb

 

Made me wonder what the Netapp reporting tools, OpsMgr, System Manager, DFM etc do when reporting the #bytes available on a HDD as Tb do they do binary or decimal conversions?

 

What are some other implications of the unit definition difference?

 

thanks