Hold on.
Did you mean I shoud enable splin-deteciton ?
It's bad scenario for me. Because if I enable splin-deteciton and Master switch fail - backup switch became a linecard at this mometn and I loss all my traffic.
"if the backup router or switch fails in a two-member Virtual Chassis configuration and split detection is enabled (the default behavior), the master router or switch takes a line-card role, and the line cards (FPCs) that do not host Virtual Chassis ports go offlin"
By the way
Best Practice: We recommend that you disable split detection for a two-member Virtual Chassis configuration if you think the backup router or switch is more likely to fail than the Virtual Chassis port interfaces