Error:

[2162] 26 Aug 15:26:26.795 # I/O error trying to sync with MASTER: connection lost

Above error happened when there is poor network connection, and you do the slave sync first time.

Possible Solution: increase slave buffer from 256m 64m 60 to 512M 128m 120

x.x.x.x:6379> config get client-output-buffer-limit

1) “client-output-buffer-limit”

2) “normal 0 0 0 slave 268435456 67108864 60 pubsub 33554432 8388608 60”

x.x.x.x:6379> config set client-output-buffer-limit “normal 0 0 0 slave 536870912 134217728 120 pubsub 33554432 8388608 60”

x.x.x.x:6379> config get client-output-buffer-limit

2) “normal 0 0 0 slave 536870912 134217728 120 pubsub 33554432 8388608 60”

Once your first sync completed. you can rollback the setting.

Refer: http://redis.io/topics/clients