In the article on the Synology 4 Bay on the DiskStation DS918 + I commented that came by using the Cloud Station Backup for continuous backup and versioning, leveraging the deduplication feature DS918 + with the Btrfs.
Despite these advanced features in backend, the client of the Cloud Station Backup It's not very polished. I have noticed that it is common for him to present an error message and ask to be restarted. Also noticed that when it is in operation backing up many files (normally the initial backup), the computer tends to slow down after a few hours. Besides, he doesn't have many options, How to delay backing up a file modified by some seconds/minutes, or exclude paths based on name or parts of it.
And another problem that was bugging me a lot is that when the Cloud Station Backup is making many backups (normally the initial), the Mozilla Thunderbird stop receiving email after a few hours, without giving any error message.
The relationship seems strange, but I realized that in two different systems, all you had to do the Cloud Station Backup be very active after a few hours the Thunderbird still working quietly, even continuing opened as if nothing had happened.
Although it seems totally unrelated, suspected of Avast. I tried then disable “SSL Scanning” the Email component of Avast.
And it's not that worked? With this option disabled the Thunderbird no question more, even with Cloud Station Backup very active.
Theoretically this option should scan only emails, When SMTP protocols, POP3 and IMAP are used over an SSL layer, but I think Avast just intercepting more SSL traffic than it should, including own Cloud Station Backup, It also uses end-to-end encryption. And how much data traveling maybe he get lost somehow. I'm not sure what this is, but the important thing is that it worked…
It is worth noting that this solution implies a safety impact, so it is necessary to be extra careful with e-mails and attachments.