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1 Cylinder = How many Tracks, 1 Track = How many GB?


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rally

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Joined: 28 Jul 2005
Posts: 37

PostPosted: Sat Feb 10, 2007 1:01 am
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1 cylinder = how many tracks
1 track = how many Giga / Mega / Kilo Bytes


I am trying to perform tracks to cylinders conversion in mainframe. Want to know how many tracks in one cylinder and how many GB or MB or KB in one Track...
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TizMe

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Joined: 05 Jan 2006
Posts: 72

PostPosted: Tue Feb 13, 2007 12:19 pm
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It depends on the DASD model used in mainframes.

Code:
Model     cyls    byte/track  byte/cyl   byte/vol
3380-J     885     47476       712140     630MB
3380-E    1770     47476       712140    1.26GB
3380-K    2655     47476       712140    1.89GB
3390-1    1113     56664       849960     946MB
3390-2    2226     56664       849960    1.89GB
3390-3    3339     56664       849960    2.83GB
3390-9   10017     56664       849960    8.51GB
9345-1    1440     46456       696840     1.0GB
9345-2    2156     46456       696840     1.5GB
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muppasani

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Joined: 03 Jan 2006
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PostPosted: Thu Mar 22, 2007 12:23 pm
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1 Track = 48 KB
1 Cylinder = 720 KB

so 1 Cylinder = 15 Tracks
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dick scherrer

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Joined: 23 Nov 2006
Posts: 19245
Location: Inside the Matrix

PostPosted: Thu Mar 22, 2007 8:33 pm
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Hello muppasani,

Please look at the table posted just before your posts and explain why your numbers are different than the table presented icon_confused.gif Also, please note that there multiple models of 3390 DASD.

A 3390-n device has a capacity of 56,664 bytes per track,of which 55,996 bytes are accessible by applications programmers. And 1 cylinder is 15 tracks.

So let us take the accessible bytes in a track which is 55,996.


Code:
1 Cylinder = 55,996 * 15  =  839,940 bytes.

so 1000 cylinders = 839,940 * 1000   

1 Megabyte =  1,048,576 (2 to the 20th power) bytes.

1000 cylinders = (839,940 * 1000 ) / 1,048,576  = 801.029 MB

1 terabyte =  2 to the 40th power or approximately a thousand billion bytes (that is, a thousand gigabytes).

1000 cylinders = (839,940 * 1000 ) / (1,048,576 * 1,048,576 )  = .000763 Terabytes
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dick scherrer

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Joined: 23 Nov 2006
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PostPosted: Fri Mar 23, 2007 7:05 pm
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Hello,

While that was published, it is not complete (if is not even totally accurate). I suspect that there was some qualifying information in that publication - like these numbers apply to DB2 allocation, not all dataset allocation.

If you want to find the capacity for an IBM device and you don't want to search in these forums, i suggest looking to IBM as they "wrote the book" for "their" devices icon_smile.gif
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priya

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Joined: 24 Jul 2003
Posts: 568
Location: Bangalore

PostPosted: Sun Jan 24, 2016 10:13 pm
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Check this table for Disk Capacity:
/references/disk.html

I have an Excel software to find the no of tracks & cylinders for a particular DASD Model. Please find the attachment:
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