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Common Server issues – FAQs and answers from those in the know

Starting lsyncd service times out, but leaves child process working

22 May 2026 @ 9:10 am

I set up lsyncd to listen changes on one directory that has hundreds of sub-directories and thousands of files (36GB in total). When I start it with systemctl start lsyncd.service or service lsyncd start, it takes a few minutes and times out. But it leaves behind a child process that seems to be fully functional. # ps aux | grep lsyn root 1238620 1.5 0.2 73136 71452 ? SN 11:54 0:09 /usr/bin/lsyncd -pidfile /var/run/lsyncd.pid /etc/lsyncd/lsyncd.conf.lua All changes in the source directory are synchronized to the target. But as the main process dies and systemctl status lsyncd.service is showing that it failed, I bet it would try restarting it infinitely if I enable the service. My config: -- lsyncd config file for 2-way sync settings { logfile = "/var/log/lsyncd/lsyncd.log", statusFile = "/var/log/lsyncd/lsyncd.status", sta

Reporting DOS attack on nginx to back server

21 May 2026 @ 8:04 pm

I'm trying to write some configuration for nginx to report a small DOS attack to a back server. Here is my current related configuration: http { limit_req_zone $binary_remote_addr zone=one:2m rate=30r/m; limit_req_status 429; limit_conn_zone $binary_remote_addr zone=addr:2m; limit_conn_status 444; proxy_cache_path /tmp/nginx/cache/ddos levels=1:2 keys_zone=ddos_cache:1m max_size=1m use_temp_path=off; server { listen 80; limit_req zone=one burst=5 nodelay; #limit_conn addr 5; client_body_timeout 5s; client_header_timeout 5s; location / { root html; index index.html index.htm; } error_page 429 /ddos-report; location = /ddos-report { internal; proxy_pass http://127.0.0.1:9999; proxy_ignore_headers Cache-Control Expires Set-Cookie X-Accel-Expires Vary; proxy_cache_key $uri;

Software to install SSL certificates on IIS? [closed]

21 May 2026 @ 5:10 pm

I'm a developer who knows just enough about IIS to manage my VPS. One inconvenience is setting up SSL certificates. I am able to do this except for one site I have. The primary domain is managed and hosted by someone else. I am managing a sub-domain of that domain. This seems to complicate everything. And I once spent two days trying to configure the certificate and still couldn't get it to work. In one case, we hired someone to take care of this for us. And all he did was run some software that took care of it. My question is, does anyone have any experience with software that could handle and simplify installing certificates on IIS when you do not control the main domain?

dnsmasq: duplicate dhcp-host IP address despite IPs being unique

21 May 2026 @ 3:29 pm

After a system upgrade, I have to reconfigure my dnsmasq installation, as the config file /etc/dnsmasq.conf.cfg01411c is now always autogenerated from /etc/config/dhcp. Now I always get this error message: mixtile@ClusterBox:~$ sudo dnsmasq --no-daemon --log-queries=extra --log-dhcp --log-debug -C /etc/dnsmasq.conf.cfg01411c dnsmasq: duplicate dhcp-host IP address 10.20.0.11 at line 26 of /etc/dnsmasq.conf.cfg01411c This happens, although the test is passed: mixtile@ClusterBox:~$ sudo dnsmasq --test dnsmasq: syntax check OK. This is the generated config file: # auto-generated config file from /etc/config/dhcp conf-file=/etc/dnsmasq.conf dhcp-authoritative log-queries=extra no-resolv enable-ubus=dnsmasq expand-hosts log-dhcp dhcp-sequential-ip all-servers log-facility=/var/log/dnsmasq.log cache-size=1000 edns-packet-max=1232 domain=lan server=192.168.178.1 i

Cloud SQL PostgreSQL 14 upgrade complete but PostgreSQL 15/16 not appearing as upgrade options after 5 days

20 May 2026 @ 5:29 pm

I successfully upgraded a Cloud SQL instance from PostgreSQL 13 to PostgreSQL 14 on May 13, 2026. It has now been 5 days and when I go to upgrade again, the dropdown only shows PostgreSQL 14 as an option — PostgreSQL 15 and 16 are not appearing. Instance details: Edition: Enterprise Availability: Highly available (multiple zones) Region: us-east1 Current version: PostgreSQL 14.22 Instance is healthy and automated backups completing normally Product is retired, no active traffic Steps taken: Validated upgrade to PG14 ✓ Disabled replication on replica Upgraded successfully to PG14 Waited 5 days — PG15 still not appearing Has anyone encountered this? Is there a known delay or a fix?

outbound https is blocked from docker containers

20 May 2026 @ 2:12 pm

I'm having trouble with containers and outbound https: $ docker run --rm -it alpine/curl curl https://google.com curl: (7) Failed to connect to google.com port 443 after 1 ms: Could not connect to server Running with host networking works, though: $ docker run --network=host --rm -it alpine/curl curl https://google.com <HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8"> <TITLE>301 Moved</TITLE></HEAD><BODY> <H1>301 Moved</H1> The document has moved <A HREF="https://www.google.com/">here</A>. </BODY></HTML> A lot of online resources mention that docker's network MTU might be too big, but that's not the case: $ ifconfig | grep mtu docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 150

Moving Site from Heroku to DigitalOcean Too Slow [closed]

20 May 2026 @ 9:17 am

We are in the process of moving our site from Heroku to self-hosting on DigitalOcean (DO). It's not a busy site in terms of numbers of users at any one time, but it is heavily processor/DB intensive so every request can potentially do a lot of requests and calculating. This is partially mitigated with a big memcache. Apart from the site DB we also access another big database which is where all the key data is held (that used to be Salesforce, but we're moving off that too). Most of the memcache is holding that key data locally to speed up response. What is working: external DB, with site hosting, memcache and site DB on Heroku. Response time averagely 0.4/s. Hope that was clear. We've been testing deployments with our UAT site and can't get past the fact that when we move the site DB off Heroku to DO, the performance crashes to the point that we get almost 100% 30-second timeouts on the test site. We tried to changeover on the production sit

Loopback testing of NVME target created using fcloop using SPDK without physical hardware support

20 May 2026 @ 4:46 am

I want to test NVME over fibre channel. I setup nvme_fcloop, nvmet_fc, and nvme_fc. How can I discover, connect and test NVME target over fibre channel using Storage Performance Development Kit (SPDK), but without physical hardware?

How to use the ssh port foward of the host from a VM? [closed]

19 May 2026 @ 9:26 am

I can do basic ssh forwarding, but I get lost when the going gets tough. On Linux host MachineA, I setup the following forwarding and it works from MachineA: localuser@MachineA $ ssh -L 4840:MachineC:4840 remoteuser@MachineB That host also runs a Windows VM, and it needs to access port 4840 on MachineC and I need to know how to do that. The VM has its network running as NAT (I can change it). How can I change the ssh command to allow access?

Monitoring if an scp connection is still transmitting

17 May 2026 @ 7:53 pm

I am using SCP to transfer a lot of date between my local computer and a remote server. I am using tmux, but the session is frozen. I used wireshark to know that the file transfers are still going, but there is a less convoluted way to know if the transfer is still going on? I do not care to know what is being transfer, just that something is being transfer and the connection is not dead.