Loki logs buffer when network is missing


I have a couple of general questions for which I could not find an answers.
I have a kubernetes cluster and I want to collect the logs from the apps running on it. I have installed promtail and loki (as a single binary, not distributred) on the cluster and promtail is sending logs to loki and loki sends them to S3 on AWS.
And I have configured loki and grafana on my home pc to look the logs from the S3.

When the cluster looses connection to the S3 I saw that the logs are buffered because when I recovered the connection after 15-20min the logs from this interval were sent to the S3. But during this time the memory used by loki increased from 50mb to 100mb.

  1. Are the chunks or indexes stored in the memory during time when the internet connection is missing?
  2. Can these buffered chunks and indexes be stored on the hard disk? Because in my case there can be days without internet connection and I don’t want to loose logs nor loki to use a lot of memory ( I want to keep set a limit of loki around 150mb for example and not to fail with out of memory, every buffering to happens on the local storage). Now I removed the connection from about an hour and a half and loki now is using 500mb and that number continues to go up…
  3. Is my setup ok from architecture point of view? I saw that it’s recommended to use distributed loki on central machine and send logs there directly there from promtail but makes the things a lot more complicated for me.

I am expecting max 1GB logs per day.

This is my Loki configuration:
auth_enabled: false
chunk_idle_period: 3m
chunk_block_size: 262144
chunk_retain_period: 1m
max_transfer_retries: 0
store: inmemory
replication_factor: 1
enforce_metric_name: false
reject_old_samples: true
reject_old_samples_max_age: 168h
- from: 2020-10-24
store: boltdb-shipper
object_store: filesystem
schema: v11
prefix: index_
period: 24h
- from: 2021-02-20
store: boltdb-shipper
object_store: s3
schema: v11
prefix: index_
period: 24h
http_listen_port: 3100
active_index_directory: /data/loki/boltdb-shipper-active
cache_location: /data/loki/boltdb-shipper-cache
cache_ttl: 24h # Can be increased for faster performance over longer query periods, uses more disk space
shared_store: s3
# aws credentials
max_look_back_period: 0s
retention_deletes_enabled: false
retention_period: 0s
working_directory: /data/loki/boltdb-shipper-compactor
shared_store: s3