Openwrt Prosody how to transfer archives to Memory?

Hi all !
I want all the archival messages of the chats and the groups are stored not on the flash, but in RAM.
Who knows, tell me how to do it, otherwise I already have not enough nerves.
Help me !

Add some kind of external storage to the router, save everything there.

tmpfs is a temporary filesystem stored in RAM.
tmpfs mount on /tmp
so data is lost when the system restarts.

The answer to my question must be done so

default_storage = "internal"
storage = {
archive = "memory"
}
archive_store = "archive"
storage = {
archive = "memory", -- ...... mod_mam
offline = "memory" -- ...... mod_offline
}

Component "conference.your domain" "muc"
name = "Prosody Chatrooms"
modules_enabled = {
"muc";
"muc_mam"
}
storage = {
muc_log = "memory"
}

</> button FTW.