Disk manufacturers use decimal-based numbers for disk sizes, so that a 146GByte drive is 146*1000*1000*1000 bytes. I have heard that this is due to legal requirements, but I am not a lawyer.
Most software, including DataONTAP, uses 1024*1024*1024 to mean a Gigabyte. So a 146Gbyte disk drive (146*1000*1000*1000) is actually 136GBytes of usable disk space.
My impression is that NetApp is one of the few vendors who are actually straight forward about this. On their quotes for new systems, they have a field for "usable space", which is based on 1024*1024*1024 calculations AND they deduct for snapshots.
Tim Sesow VP Engineering 303-948-3360 cell 303-809-8070
-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Jack Lyons Sent: Wednesday, May 12, 2004 8:26 AM To: 'toasters@mathworks.com' Subject: Size calculations
Can you tell me whether or not a TB = 1000 GB or 1024 GB In my volume properties screen:
Used Capacity: 1.18 TB % Used: 90% Total Capacity: 1.31 TB
But in my Manage Volumes screen it shows I have 127 GB available. 1.31 - 1.18 = .13 TB = 133.12 GB if 1 TB = 1024 GB 1.31 - 1.18 = .13 TB = 130 GB if 1 TB = 1000 GB
127 GB = .127 TB if TB = 1000 GB 127 GB = .130 TB if TB = 1024 GB
so it seems that in one screen they use 1 conversion factor and another screen they use a different one.
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