Every “is my VPS out of memory?” decision rests on two numbers from /proc/meminfo, and most operators read the wrong one. MemFree tells you how much RAM is completely unused…
Read MoreTLS Session Resumption and OCSP Stapling on a Single-vCPU VPS: Reduce Handshake CPU Without Weakening Security
On a small VPS, the RSA or ECDSA signing operation in a TLS 1.3 handshake is often the most expensive thing your CPU does per request. Full handshakes from cold…
Read MoreFinding CPU Hotspots on a Small VPS with perf and Flamegraphs
top shows a process at 100% CPU and tells you nothing about which function is burning it. That is the gap perf and flamegraphs close: instead of sampling at the…
Read MoreVerifying Backup Integrity with Checksums Before You Need a Restore
Most backup failures are not discovered during the outage — they are discovered during the restore, when it is far too late. A backup job that exits zero every night…
Read MoreDiagnosing DNS Resolver Latency on a VPS with dig and tcpdump
DNS resolution latency is invisible until it is not. A resolver that answers in 5 ms and one that answers in 2 seconds produce identical application code and wildly different…
Read MoreEphemeral Port Exhaustion and SO_REUSEPORT Tuning on Linux Servers
When a busy server starts refusing new connections but traffic and CPU look normal, the cause is often a quiet resource limit: the ephemeral port range, or the loading of…
Read MoreTuning net.ipv4.tcp_rmem for High-Latency VPS Workloads: Buffer Sizing by Bandwidth-Delay Product
The default 6 MB TCP receive-buffer ceiling caps single-stream throughput on high-RTT links. Measure the bandwidth-delay product, size tcp_rmem and core.rmem_max correctly, and verify with live socket statistics.
Read MoreFinding Packet Loss on a VPS Uplink with tcpdump, nstat, and eBPF Drop Tracing
Map packet-loss symptoms to the layer that caused them using kernel counters, targeted tcpdump captures, and eBPF kfree_skb reason codes. Includes a counter-to-cause reference table.
Read MoreConntrack Table Exhaustion on a VPS: Measuring nf_conntrack Before Connections Drop
Measure nf_conntrack_count against nf_conntrack_max, then size the table and timeouts from real traffic. Includes a per-workload entry-consumption table and a post-change regression check.
Read MoreRaising File Descriptor and Process Limits on a VPS for High Connection Counts
Most services on a VPS have a hard ceiling that has nothing to do with CPU, RAM, or bandwidth: the number of open file descriptors and processes they are permitted….
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