RMAN channel and getting exact backup/restore estimation
first of all, how do we calculate the best number of channel?
exact number of disk? or lun? or cpu count? disk ID?
what in case of ASM?
the reason is that currently I was restoring a db as a duplicate on another server for testing. I use a provided script which create 3 channel. then I use another script to get the estimation end date (below are sample only, but it something like this)
SQL> /
SID START_TIME TOTALWORK SOFAR DONE% END_AT
---------- ----------------- ------------ ------------ ------- -----------------
1 30/03/17 11:08:43 21,005,822 20,845,963 99.24 30/03/17 14:26:16
1768 30/03/17 11:21:35 23,203,966 833,651 3.59 30/03/17 14:49:44
1711 30/03/17 11:47:36 20,983,934 3,513,733 16.74 30/03/17 14:29:29
except when after some of the process are done, there are new 2 process with later end time