MongoDB secondary companies do not catch up

I have a set of replicas that I am trying to upgrade to the first with a large amount of memory and updated disk space. So I raided a couple of disks together on the new primary, rsync'd data from the secondary and added it to the replica set. After checking rs.status (), I noticed that all secondary users are about 12 hours behind the main one. Therefore, when I try to force a new server to the first place, it will not work, because it is not updated.

This seems like a big problem, because in case the primary fails, we are at least 12 hours and almost 48 hours behind.

All overlays of oplogs and oplogsize are quite large. The only thing I can understand is that I am doing a lot of writing / reading on the primary, which can block the server, preventing it from catching correctly.

Is there a way to make the secondary object catch up with the primary?

Currently 5 servers with the last 2 should replace 2 other nodes. node with _id as 6 should be replaced with primary. node, which is the farthest from the primary optime, is just over 48 hours away.

{
"set" : "gryffindor",
"date" : ISODate("2011-05-12T19:34:57Z"),
"myState" : 2,
"members" : [
    {
        "_id" : 1,
        "name" : "10******:27018",
        "health" : 1,
        "state" : 2,
        "stateStr" : "SECONDARY",
        "uptime" : 20231,
        "optime" : {
            "t" : 1305057514000,
            "i" : 31
        },
        "optimeDate" : ISODate("2011-05-10T19:58:34Z"),
        "lastHeartbeat" : ISODate("2011-05-12T19:34:56Z")
    },
    {
        "_id" : 2,
        "name" : "10******:27018",
        "health" : 1,
        "state" : 2,
        "stateStr" : "SECONDARY",
        "uptime" : 20231,
        "optime" : {
            "t" : 1305056009000,
            "i" : 400
        },
        "optimeDate" : ISODate("2011-05-10T19:33:29Z"),
        "lastHeartbeat" : ISODate("2011-05-12T19:34:56Z")
    },
    {
        "_id" : 3,
        "name" : "10******:27018",
        "health" : 1,
        "state" : 1,
        "stateStr" : "PRIMARY",
        "uptime" : 20229,
        "optime" : {
            "t" : 1305228858000,
            "i" : 422
        },
        "optimeDate" : ISODate("2011-05-12T19:34:18Z"),
        "lastHeartbeat" : ISODate("2011-05-12T19:34:56Z")
    },
    {
        "_id" : 5,
        "name" : "10*******:27018",
        "health" : 1,
        "state" : 2,
        "stateStr" : "SECONDARY",
        "uptime" : 20231,
        "optime" : {
            "t" : 1305058009000,
            "i" : 226
        },
        "optimeDate" : ISODate("2011-05-10T20:06:49Z"),
        "lastHeartbeat" : ISODate("2011-05-12T19:34:56Z")
    },
    {
        "_id" : 6,
        "name" : "10*******:27018",
        "health" : 1,
        "state" : 2,
        "stateStr" : "SECONDARY",
        "optime" : {
            "t" : 1305050495000,
            "i" : 384
        },
        "optimeDate" : ISODate("2011-05-10T18:01:35Z"),
        "self" : true
    }
],
"ok" : 1
}