Why am I only able to see 255 volumes in the chooser, and why do all 255 volumes disappear when I add the 256th volume?

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  • Product:
    ExtremeZ-IP
  • Version:
    4.0-Current
  • Document Type:
    FAQ
  • Revised:
    2/27/2007
  • Reviewed:
    2/27/2007

Question:

Why am I only able to see 255 volumes in the chooser, and why do all 255 volumes disappear when I add the 256th volume?

Answer:

This is a limitation of AFP which relies on an 8 bit variable to identify the number of volumes to report to the chooser and network browser.

For 255 volumes, the binary value of this variable is equal to 11111111 and all 255 volumes are able to be seen in the chooser and network browser.

At the 256th volume all volumes disappear from the chooser and network browser. This is because the 9 bit binary value 100000000 read as an 8 bit binary value will truncate the 9th bit leaving a value of 00000000.

Adding additional volumes (257) will be read as 10000001 and only one volume will be seen in the chooser and network browser.

Note: This issue will only occur if the user logging in has access to more than 255 volumes. ExtremeZ-IP numbers the volumes on a per user basis.

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