Usable disk space for 300GB

I think that your local friendly TC may help you in finding an answer to this question .. You can even ask a CE if you think it's easier to reach a CE.

I found a nice chart the other day showing useable capacity on a physical drive in the following document: EMC Symmetrix DMX-4 Product Guide

The specific table of interest is "Table 13 Symmetrix DMX-4 disk drive capacities"

The answer depends on a few factors such whether you are using this for Opensystems or Mainframe and then the next major factor will be how you break the drive down protection and slice wise (Raid 1, Raid 5, etc.) and how much capacity you leave.

Formatted raw capacity for Opensystems emulation is ~279GB.

Looking at the DMX3-24 we have it uses 1GB=1024*1024*1024

so 146GB disk gives me 140014m(136GB)

symdev -sid 1854 show 0B9F

Device Physical Name : /dev/rdsk/c32t9d2

Device Symmetrix Name : 0B9F
Device Serial ID : 5400B9F000
Symmetrix ID : 00019010xxxx

Device Group Name : ifrmd2pb_data
Device Logical Name : DEV004

Attached BCV Device : N/A

Attached VDEV TGT Device : N/A

Vendor ID : EMC
Product ID : SYMMETRIX
Product Revision : 5771
Device WWN : 600604800001901018xxxx303042xxxx
Device Emulation Type : FBA
Device Defined Label Type: N/A
Device Defined Label : N/A
Device Sub System Id : 0x000C

Device Block Size : 512

Device Capacity
{
Cylinders : 18414
Tracks : 276210
512-byte Blocks : 17677440
MegaBytes : 8632
KiloBytes : 8838720
}

Device Configuration : RDF1+Mir (Non-Exclusive Access)

Device is WORM Enabled : No
Device is WORM Protected : No

SCSI-3 Persistent Reserve: Disabled

Dynamic Spare Invoked : No

Dynamic RDF Capability : None

Device Service State : Normal

Device Status : Ready (RW)
Device SA Status : Ready (RW)

Front Director Paths (2):
{
----------------------------------------------------------------------
POWERPATH DIRECTOR PORT LUN
--------- ---------- ---- -------- ---------
PdevName Type Type Num Sts VBUS TID SYMM Host
----------------------------------------------------------------------
/dev/rdsk/c32t9d2 PARENT FA 04D:0 RW 000 09 002 002
/dev/rdsk/c34t9d2 CHILD FA 13D:0 RW 000 09 002 002
}

Mirror Set Type : [Data,R2 Remote,Data,N/A]

Mirror Set DA Status : [RW,RW,RW,N/A]

Mirror Set Inv. Tracks : [0,0,0,0]

Back End Disk Director Information
{
Hyper Type : Data
Hyper Status : Ready (RW)
Disk [Director, Interface, TID] : [15D, D,10]
Disk Director Volume Number : 362 (0x169)
Hyper Number : 11
Disk Capacity : 140014m
Disk Group Number : 4

Hyper Type : R2 Remote
Hyper Status : Ready (RW)
Disk [Director, Interface, TID] : [N/A,N/A,N/A]
Disk Director Volume Number : N/A
Hyper Number : N/A

Hyper Type : Data
Hyper Status : Ready (RW)
Disk [Director, Interface, TID] : [11D, D,10]
Disk Director Volume Number : 362 (0x169)
Hyper Number : 11
Disk Capacity : 140014m
Disk Group Number : 4
}

BCV Pair Information
{
Standard (STD) Device Symmetrix Name : 0B9F
Standard (STD) Device Serial ID : Not Visible
Standard (STD) Device Group Name : ifrmd2pb_data
Standard (STD) Composite Group Name : Not/Grouped

BCV Device Symmetrix Name : 1941
BCV Device Serial ID : Not Visible
BCV Device Associated Group Name : ifrmd2pb_data
BCV Device Associated CG Name : Not/Associated

BCV Device Status : Ready (RW)

State of Pair ( STD <=\=> BCV ) : Split
Time of Last BCV Action : Wed Dec 26 07:22:23 2007

State of BCV Mirrors : Synchronized

BCV State Flags : (Emulation)
Percent Split : 100%

Number of Inv. Tracks for STD Device : 0
Number of Inv. Tracks for BCV Device : 0
}

RDF Information
{
Device Symmetrix Name : 0B9F
RDF Type : R1
RDF (RA) Group Number : 35 (22)

Remote Device Symmetrix Name : 0AFF
Remote Symmetrix ID : 00018775xxxx

R2 Device Is Larger Than The R1 Device : False

RDF Mode : Asynchronous
RDF Adaptive Copy : Disabled
RDF Adaptive Copy Write Pending State : N/A
RDF Adaptive Copy Skew (Tracks) : 65535

RDF Device Domino : Disabled

RDF Link Configuration : GigE
RDF Link Domino : Disabled
Prevent Automatic RDF Link Recovery : Enabled
Prevent RAs Online Upon Power ON : Enabled

Device RDF Status : Ready (RW)

Device SA Status : Ready (RW)
Device RA Status : Ready (RW)
Device Link Status : Ready (RW)

Device Suspend State : N/A
Device Consistency State : Disabled
RDF R2 Not Ready If Invalid : Disabled

Device RDF State : Ready (RW)
Remote Device RDF State : Write Disabled (WD)

RDF Pair State ( R1 <===> R2 ) : Consistent

Number of R1 Invalid Tracks : 0
Number of R2 Invalid Tracks : 0

RDFA Information:
{
Session Number : 34
Cycle Number : 40051
Number of Devices in the Session : 20
Session Status : Active

Session Consistency State : Enabled
Minimum Cycle Time : 00:00:30
Average Cycle Time : 00:00:29
Duration of Last cycle : 00:00:29
Session Priority : 41

Tracks not Committed to the R2 Side: 0
Time that R2 is behind R1 : 00:00:41
R1 Side Percent Cache In Use : 0
R2 Side Percent Cache In Use : 0
}
}

300GB is 300x1000x1000x1000 bytes, so simply devide 300.000.000.000 by 1024x1024x1024 to get the Binary GigaBytes or as it should be called: Gibibyes (GiB).

The Systeme International made up the use of kilo, mega, giga, tera even before the Gigabyte was invented. Technicians are used to use 1024 when they say 1 kiloByte, when in fact they created the error there. kilo Means 1000, not 1024. 1024 Bytes is KiB, 1 MegaBytes = 1 MebiByte and so forth.

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