topic MSA2312i reports unformatted 1TB disk size as 931.5GiB in MSA Storage

MSA2312i reports unformatted 1TB disk size as 931.5GiB

mikeh19d — Fri, 26 Aug 2011 18:39:52 GMT

I have two identical MSA2312i with 1TB SATA disks. I have setup and configured one with no problem. I went to start the second MSA and all of the disks are showing a size of 931.5GiB. Why would the same identical disks in one MSA show a true size and the second MSA shows a smaller disk size? I have never seen disk size reported in "GiB". Can i get some help, thanks.

Re: MSA2312i reports unformatted 1TB disk size as 931.5GiB

Johan Guldmyr — Mon, 29 Aug 2011 05:06:19 GMT

Are the controller firmwares or the disk drive models different?
I thought GiB is the new thing that's meant to be better than the rest but it confuses me.

Re: MSA2312i reports unformatted 1TB disk size as 931.5GiB

Dennis Handly — Mon, 29 Aug 2011 05:51:26 GMT

One of these units may be in the inflated marketing speak and the other other in nerd speak.

I.e. marketing speak is in units of 1000s. Nerd speak is in units of K, 1024.

Re: MSA2312i reports unformatted 1TB disk size as 931.5GiB

Johan Guldmyr — Mon, 29 Aug 2011 06:01:02 GMT

Yeah, I guess that there was a change somewhere in a firmware that changed the way it's represented with the 1TB on the disk drives generally has 1000 bytes per kilobytes ( so it looks like more ) and actually there is 1024 bytes per kilobyte - so there is less.

The GiB is 'GibiBytes' which is 2^30 Bytes or 1024 MebiBytes which is 2^20 Bytes.

While one MegaByte could be one million Bytes (10^6) or 2^20 Bytes (with the 1024 Bytes per kiloBytes).

http://xkcd.com/394/

and

http://en.wikipedia.org/wiki/Gibibyte

Re: MSA2312i reports unformatted 1TB disk size as 931.5GiB

mikeh19d — Tue, 30 Aug 2011 14:11:26 GMT

All of the firmware has been updated and current. I haven't heard about any new references to storage measurements... thanks for the reply.

Re: MSA2312i reports unformatted 1TB disk size as 931.5GiB

Uwe Zessin — Wed, 31 Aug 2011 08:43:16 GMT

From the MSA Reference Guide:

About size representations
[...]
Operating systems usually show volume size in base 2. Disk drives usually show size in base 10. Memory
size is always shown in base 2. In SMU, the base for entry and display of storage-space sizes can be set
per user or per session. When entering storage-spaces sizes only, either base-2 or base-10 units can be
specified.

I don't have a box here and am too lazy to check the documentation, sorry, so I can't tell where to change this.