Ciprico 4400 user manual SAN Software Examples

MediaVault 4440 User Manual

1:1 Relational Create eight zones:

•Zone 1 contains ports 1 and 5

•Zone 2 contains ports 2 and 6

•Zone 3 contains ports 1 and 7

•Zone 4 contains ports 2 and 8

•Zone 5 contains ports 3 and 5

•Zone 6 contains ports 4 and 6

•Zone 7 contains ports 3 and 7

•Zone 8 contains ports 4 and 8

In the Plain and Simple configuration, the setting works, though occasionally one channel of the array might test the corresponding channel of the other array and/or the other computer, causing a very slight amount of extra traffic on the line. The Host-Grouped method eliminates this crosstalk between the arrays, but does not correct for the crosstalk between the computers. In the 1:1 Relational configuration, this problem is alleviated, but the drawback is that it is harder to set up on the switch. Whenever possible, set up 1:1 Relational zones if the Storage Area Network (SAN) software supports it.

SAN Software Examples

Example 1

Here is a simple SAN software example, using two dual-channel computers and four vPODs in an MV 4440. The computers are attached to ports 1, 2 and 3,4 respectively of the switch, and the array attached to ports 5 through 8. Although this setup can function unzoned, zoning is required to keep the computers from "chatting" with each other, rather than the array. Two zones are required. See Example 2 above for the zoning.

At first, everything seems OK, until one computer formats the array. The other computer thinks the array is unformatted and tries to erase the array whenever possible. If one computer writes files to the array, the directory will be in that computers' cache and the other computer might not see it. If the other computer writes to the array, the first computer might destroy those files, thinking that part of the array is blank.

To avoid this, SAN software is required. In it's simplest form, SAN software sends information to both computers that it is updating the array. This information is usually passed through Ethernet, rather than Fibre Channel.

E-4 MV 4440_Ciprico Inc.