In what seems to be a repeat of my previous topic (Slow sending and receiving of email ), one of my Sympl servers is again running incredibly slowly, e.g.
- Emails taken 30+ seconds to send (in Thunderbird and Neomutt, so I don’t think it’s a client problem)
- IMAP logins take a similarly long time
- Websites are slow to respond
- Running commands via sudo has a noticeable delay (5+ seconds)
Basically it’s as if everything on the server is running slower than usual, taking 5-30+ seconds to respond instead of more or less instantly. My other Sympl server is working fine.
I can’t work out what the problem is. I’ve looked at the following:
- Load average is negligible (0.1 or less)
- 75% of the RAM is free
- No swap in use
- Both CPU cores are at <1% usage
- No users logged in other than me (I’m the only one with access)
- No suspicious processes
Things I’ve tried so far:
- Disabling unnecessary services - this seems to break monitoring and causes more problems.
- Upgrading from VPS 2 to 4, which increases the RAM from 2GB to 4GB
- Removing allow rules from the firewall for services I never use (e.g. POP3)
Can anyone suggest anything else I can try please? Although I can still use the server, it’s for my business so websites loading slowly etc. looks really bad.
I’ve noticed this warning repeats itself in the log:
Jul 13 09:38:31 borusa dovecot: auth-worker(3371): Warning: read(/run/dovecot/sympl-mail-dict-proxy): dict lookup took 5.013 secs (5.013 in dict wait, 0.000 in other ioloops, 0.000 in locks): Lsharedfirstname.lastname@example.org
- Sympl Version [9.0/10.0]: 10.0
- Sympl Testing Version? [Yes/No] No
- Debian Version [Buster/Stretch]: Buster
- Hardware Type? [Dedicated/Virtual/Pi] Virtual
- Hosted On? [name of hosting co] Mythic Beasts