If a Linux VPS reports System clock synchronized: no, first identify which time service is managing the clock, then verify that it can receive NTP replies over UDP 123. A running service is not proof of synchronization. On most VPSs, a single chrony instance with several reachable sources, a drift file, and an initial makestep policy is the most robust setup. Check the provider’s own time source before opening access to public servers.
Antihost offers Linux VPS plans with full root access, unlimited traffic on a 1 Gbps port and a 14-day free trial.
What “not synchronized” means
Linux exposes two related but different facts. timedatectl can show that an NTP service is active while also reporting System clock synchronized: no. “NTP service: active” means a daemon is enabled or running; it does not mean that the daemon has selected a source and received valid replies. Synchronization status changes only after the client has usable measurements.
As an Amazon Associate I earn from qualifying purchases.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Incorrect time can invalidate TLS certificates, break Kerberos and other authentication systems, disorder distributed logs, confuse scheduled jobs, and make database or message-queue timestamps appear to move backward. A VPS can also lose or gain seconds when its virtual machine is paused, migrated, or resumed, so the guest must keep checking after boot and under normal load.
1. Establish the current state before changing configuration
Read the clock and timedatectl status
date -u
timedatectl
systemctl list-units --type=service | grep -E 'chrony|chronyd|timesyncd|ntp'Record the UTC time, time zone, whether NTP is enabled, and whether the clock is currently marked synchronized. The service-list command finds common unit names without assuming a particular distribution.
#1 Best Overall
- [Ultra-Lightweight Ear Buds Designed for Small Ears] Each earbud weighs only 3.7g and features a compact, ergonomic in-ear design made especially for small ears. Secure, low-profile, and comfortable for workouts, all-day wear or overnight sleeping.The ultra-slim profile sits flush in your ear with no hard edges poking or rubbing, so you can even sleep on your side without discomfort.
- [Immersive Stereo Sound with TOZO OrigX Technology] TOZO OrigX tuning delivers clear vocals, balanced mids, and natural stereo sound for music, podcasts, and videos.
- [Long Battery Life for Daily Use] Get up to 7 hours of playtime on a single charge, with up to 32 hours total using the charging case—ideal for workdays, commuting, and extended listening sessions.
- [Bluetooth 5.3 & Stable Connection] Bluetooth 5.3 provides fast pairing, stable wireless performance, and reduced dropouts as you move around home or office.
- [Deep Bass with Clear Vocals] High-performance drivers produce punchy bass while keeping vocals clean and detailed for everyday listening.
Find every possible time daemon
systemctl status chrony --no-pager
systemctl status chronyd --no-pager
systemctl status systemd-timesyncd --no-pager
systemctl status ntp --no-pager
systemctl status ntpd --no-pagerSome commands will report that a unit does not exist; that is normal. What matters is whether more than one daemon is enabled or running. Ubuntu documentation notes that timedatectl steps back when chrony is installed, so chrony, systemd-timesyncd, and ntpd should not be left to adjust the same clock concurrently.
Use timedatectl only as the distribution-level switch
sudo timedatectl set-ntp trueThis asks the distribution to enable its supported network-time service. It does not repair DNS, firewall rules, an invalid server list, or a failed provider time source. Inspect the selected daemon and its logs after running it.
2. Select one synchronization service
Why chrony is usually the better VPS choice
Chrony is a full NTP client with source selection, detailed statistics, and controls for systems that experience drift or intermittent connectivity. The chrony project’s FAQ generally prefers it over timesyncd when a full-featured client is wanted and recommends at least three servers for reliable operation. Those characteristics suit virtual machines that can be suspended or whose virtual clock rate changes under host load.
When systemd-timesyncd is sufficient
The systemd client is intentionally small and implements SNTP only, according to the systemd manual. It is appropriate for a simple systemd-managed client with reliable, trusted sources and no need for chrony’s extensive diagnostics. It steps large offsets and slews smaller ones, but offers fewer controls for source analysis.
Example Debian or Ubuntu conversion to chrony
sudo apt update
sudo apt install chrony
sudo systemctl disable --now systemd-timesyncd 2>/dev/null || true
sudo systemctl disable --now ntp 2>/dev/null || true
sudo systemctl enable --now chrony
systemctl status chrony --no-pagerPackage and unit names vary. On distributions that use the daemon unit directly, use chronyd instead of chrony. On a Red Hat-family system, install the distribution’s chrony package with its native package manager and enable the unit documented by that release. Do not copy a Debian path or service name blindly.
Rank #2
- 【IP68 Waterproof Multifunctinal Smart Watch】Torjalph fitness activity tracker smart watch is IP68 waterproof technology ,you can wear it when swimming,handwashing,it's rain-proof which means that you perform multiple exercise modes outside without worrying about sweat or rain corroding your fitness smart watch,and this watch equipped with a 230 mAh large capacity battery magnetic charging ,and this sports activity tracker watch can be used 5-7 days If fully charged.
- 【Larger 1.83'' Full Screen Watch & Multi-dial Selection】1.83 inch full HD color touch screen smart watch for men / women provides excellent 240*284 resolution image quality ,This Bluetooth smart watch offers a better touch experience and remarkable immersion and ,more than 200 watch faces for you to choose from App"Da Fit ", you can change the dial style according to your mood to wear keeping the world on your wrist
- 【Accurate Activity Tracker Smart Watch 】sports watch activity tracker uses sweat and dust resistant breathable silicone strap, our Fitness Tracker Smart Watch for Android iOS Phones supports 12 sports modes,walking,running,bicycle,swimming,badminton,basketball,football,rope skipping. This bluetooth calls smart watch for men women is lightweight and stylish, bringing more convenient and relaxing sports experience while also providing more protection.
- 【Your 24 Hour Personal Daily Health Monitor】Fitness watch for women men full touch screen IP67 waterproof bluetooth smartwatch for Android iOS Phones with heart rate blood pressure monitor multifunction Andriod smart watch with steps counter sleep monitor sports fitness watch, monitoring blood oxygen saturation allows you to understand your physical condition in real time to track fitness progress ,to know your health status in time.
- 【More Functions Bluetooth Call Smart Watch】This fitness activity smart watch full screen for iPhone and Android phones includes a bunch of new features including:The bluetooth smart watch can hang up the phone, receive and display WhatsAPP /Text /Facebook /Twitter /Messenger reminder.Support sedentary reminder, alarm clock, stopwatch, timer,weather information,music control, remote camera control compatible with Android 5.0 and above or iOS 9.0 and above smartphones.
If you deliberately keep systemd-timesyncd, stop and disable chrony and ntpd first, then inspect it with:
sudo systemctl disable --now chrony 2>/dev/null || true
sudo systemctl disable --now chronyd 2>/dev/null || true
sudo systemctl disable --now ntpd 2>/dev/null || true
sudo systemctl enable --now systemd-timesyncd
systemctl status systemd-timesyncd --no-pager
timedatectl timesync-status3. Diagnose chrony with evidence, not assumptions
Read tracking and source selection
chronyc tracking
chronyc sources -v
chronyc sourcestats -v
journalctl -u chrony -b --no-pagerIf the unit is named chronyd, use journalctl -u chronyd. In chronyc sources -v, ^* identifies the selected source and ^+ identifies a usable candidate. A Reach value of zero means chrony has received no valid responses from that configured source. It is a networking or source-availability symptom until proven otherwise, not a reason to increase polling intervals.
Interpret common outputs
- No sources listed: the configuration has no usable
poolorserverentry, the file was not read, or all names failed to resolve. - Sources shown but every Reach value is 0: requests or replies are being blocked, the names resolve to unusable addresses, the source is down, or the provider disallows that traffic.
- Reach is nonzero but no
^*appears: replies are arriving, but the candidates are being rejected because of delay, dispersion, stratum, falseticker checks, or insufficient agreement. - A selected source exists but the offset remains large: allow the configured startup step, check for a suspended or overloaded guest, and inspect whether another daemon or a host integration is changing the clock.
Check systemd-timesyncd when it is the chosen client
systemctl status systemd-timesyncd --no-pager
timedatectl timesync-status
journalctl -u systemd-timesyncd -b --no-pagerLook for name-resolution errors, repeated timeouts, unreachable servers, or messages indicating that the clock was stepped. A healthy process with no selected server is the same operational problem as an active chrony service with Reach 0.
4. Apply a VPS-suitable chrony configuration
Use several sources and preserve the learned drift
A conservative Internet-client baseline from the chrony project is:
pool pool.ntp.org iburst
driftfile /var/lib/chrony/drift
makestep 1 3
rtcsyncUse the drift-file location supplied by your distribution; it may differ from this example. The pool directive obtains multiple servers. You may instead specify several trusted server lines or the VPS provider’s documented endpoint. The chrony FAQ advises at least three servers for reliable operation, because one source can fail or provide a misleading measurement.
The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Rank #3
- [Low Noise High Fidelity] New bee guitar cord with 22AWG oxygen-free-copper center conductors provides enhanced signal transfer, the PVC insulation material and the high-density stranded copper double shield provide noise rejection for quiet operation
- [Ideal for Choice] New bee 1/4 straight and right angle metal connectors, ensures a secure connection in any instrument, pedal, or amp jack. L shape great fro on stage guitar stands
- [Wide Compatible] Suitable for mixer, power amplifier, microphone, effector, decoder, equalizer, electoronic organ, electric guitar, electric bass and other electronic equipments. Widely used in the installation of smart home, karaoke speaker, professional stage audio, etc
- [Easy Disassemble] Making incidental repairs quick and easy! Very nice, flexible cable
- [Dont Hesite to Order] 24 hours customer services and professional technology team are standing by
iburst: sends an initial burst of measurements so a newly started client can acquire time quickly.makestep 1 3: permits a correction larger than one second during the first three updates, avoiding a long wait when a fresh VM starts far off. After that startup window, chrony normally slews rather than repeatedly jumping the clock.driftfile: stores the observed frequency error so chrony can compensate for the guest clock’s tendency to run fast or slow across restarts.rtcsync: keeps the hardware or virtual real-time clock aligned where the platform supports that operation. It does not replace network synchronization.
Edit, restart, and verify
- Back up the existing chrony configuration.
- Keep the distribution’s include directives and drift-file path unless its documentation says otherwise.
- Add a provider source or several trustworthy servers, plus
iburst. Avoid deleting all existing sources merely because one is slow. - Restart the one active daemon:
sudo systemctl restart chrony # or chronyd
chronyc tracking
chronyc sources -vChanges are not proven until a source is selected and the tracking output shows a finite reference time, offset, and frequency. Restarting a service only proves that its process can start.
5. Check DNS, UDP 123, and return traffic
Verify names and addresses
getent ahosts pool.ntp.org
resolvectl query pool.ntp.org 2>/dev/null || trueUse the actual names in your configuration. If resolution fails, fix the VPS resolver, search domain, or provider DNS setting before troubleshooting NTP. If a name returns both IPv4 and IPv6, a broken path on one family can produce intermittent failures; test the family that chrony is actually using from its source output and logs.
Audit every filtering layer
NTP requests and replies normally use UDP port 123. Check, in order:
- the VPS host firewall (for example, nftables, iptables, or a distribution firewall);
- the cloud security group, network ACL, or egress policy;
- any upstream provider policy that restricts outbound UDP;
- stateless rules that must explicitly allow reply traffic; and
- the remote server’s availability and rate limits.
An ICMP ping succeeding does not demonstrate that NTP works: ping uses a different protocol, and many time services do not answer ICMP. Likewise, opening inbound UDP 123 is normally unnecessary for a client and can create exposure; the client needs outbound requests and permitted return packets.
Recommended Free Tools
Capture packets when Reach remains zero
sudo tcpdump -ni any udp port 123Start the capture, restart or allow a poll interval, and compare outgoing requests with incoming replies. Outbound packets without replies point to a remote path, egress rule, or source problem. Replies visible on the interface but absent from chrony point to local filtering, address-family issues, or malformed configuration. Chrony’s troubleshooting guidance names packet capture tools such as tcpdump and Wireshark for this case. Stop a capture that could contain sensitive network metadata when you have enough evidence.
Rank #4
- Digital Family Calendar: BSIMB digital calendar wall touch screen puts an end to your chaotic life. Designed for busy families, the digital calendar keeps you organised and in step with your family. Assign different colours and tasks to each family member to make family scheduling easier and more intuitive.
- Easy Setup and Auto-Sync: Plug in, connect to WLAN and auto-syn your electric calendar in minutes. Digital wall calendar compatible with Google calendar, iCloud calendar, Outlook calendar, Cozi calendar and Yahoo calendar. Add events directly on the device or through the ecalendar app. Electronic calendar stays current whether you're at work or traveling—no manual updates needed.
- All-In-One Home Assistant: Smart calendar builds habits and encourage independence with personalised chores. Display daily meal plan to reduce the daily ‘What's for dinner?’ stress. To-do lists keep track of everything you want. Turning chores into valuable achievements with stars and rewards, making life easier and more enjoyable.
- Manage Anytime Anywhere: BSIMB electronic calendar for family stay connected with the powerful ecalendar app. Access and manage your digital wall calendar anytime, anywhere with free features like stars & rewards, photo screensaver, chore charts, meals plans, to-do lists etc. Electronic planner paid features like Magic Import tailor advanced tools for users with special needs.
- Stay in Touch with Loved Ones: Share photos or videos from your phone to electronic wall calendar with app, instantly update your life moment, and keep in touch with your family, especially those who are far away; you can also surprise your smart calendar digital wall by sending him a wish card; it's also great for keeping tech-illiterate elders in touch with the youngsters.
6. Correct a badly wrong clock safely
Chrony normally slews small errors gradually so applications see a smooth rate. A newly provisioned VPS can be minutes or hours off, however, and waiting for a slow slew may leave certificates, logs, and scheduled tasks unusable. The makestep policy allows a large correction during startup. Systemd-timesyncd similarly steps large offsets and slews smaller ones.
Do not repeatedly run date --set or another manual clock-setting command while a daemon is active. Competing corrections make source selection harder to interpret and can disturb software that depends on monotonic or ordered timestamps. If an emergency manual correction is unavoidable, stop the active time service first, make one deliberate correction, then start the service and verify its selected source.
After a step, review applications that create time-sensitive records. A timestamp jump cannot be undone in existing logs, although a healthy monotonic clock interface protects many interval measurements from wall-clock changes.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.7. Use the VPS provider’s time source when appropriate
Azure virtual machines
Microsoft documents host synchronization and a PTP device exposed as /dev/ptp_hyperv for supported Linux virtual machines. The available method depends on the image, kernel, and host integration. Follow the current Azure guidance for your VM rather than assuming a public Internet pool is always the best source. Host synchronization can also explain a clock change after a pause or migration.
Amazon EC2
AWS documents its link-local Amazon Time Sync Service at 169.254.169.123 and recommends that endpoint as the direct EC2 source. Because it is link-local, it does not require a route to the public Internet, but the guest firewall and image configuration must still permit the traffic. Do not substitute this address on a different provider.
Other providers
Look for a documented host clock, PTP device, or link-local NTP endpoint in the provider’s Linux image and kernel instructions. Provider integration may survive host maintenance better than an external source, but it is still wise to retain additional trustworthy sources when the provider supports that design. Never mix undocumented endpoints copied from another platform.
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Scan for outdated or missing drivers - takes under a minute3Repair Windows errors before they cause bigger problems8. Chrony and systemd-timesyncd compared
| Area | Chrony | systemd-timesyncd |
|---|---|---|
| Protocol and features | Full NTP client with richer source selection, statistics, and controls. | Minimal SNTP service; large offsets are stepped and small offsets are slewed. |
| Best fit | VPSs with clock drift, several sources, intermittent connectivity, or a need for detailed troubleshooting. | Simple systemd-managed clients with dependable sources and modest requirements. |
| Diagnostics | chronyc tracking, sources -v, and sourcestats -v. |
timedatectl timesync-status, service status, and journal output. |
| Conflict risk | Must not run concurrently with systemd-timesyncd or ntpd. | Must not run concurrently with chrony or ntpd. |
Choose one based on the VPS’s needs, not on which command happens to return first. A minimal timesyncd setup can be perfectly healthy; chrony is not automatically more accurate without reachable sources and correct network policy.
9. Troubleshoot by symptom
“System clock synchronized: no” immediately after installation
- Wait for an initial poll after enabling the service.
- Run the daemon’s status and journal commands.
- Check
chronyc sources -vortimedatectl timesync-statusfor a selected source. - Confirm DNS and UDP 123 before changing poll settings.
Chrony is active, but every source has Reach 0
- Resolve each configured hostname.
- Inspect egress rules, security groups, host firewall, and stateless return rules.
- Use
tcpdumpto determine whether replies reach the VPS. - Test a provider-documented source if one exists.
Sources respond, but no source is selected
- Check for a falseticker, excessive delay, high dispersion, or disagreement among sources in
sourcestats. - Use at least three trustworthy sources.
- Remove stale or unreachable entries and restart the daemon.
The clock jumps after suspend, migration, or heavy load
- Confirm that only one guest daemon is running.
- Check provider host or PTP integration.
- Retain
makestepfor startup recovery and let chrony relearn frequency through its drift file. - Recheck tracking during ordinary load, not only immediately after boot.
NTP works over IPv4 but fails intermittently
- Compare the addresses returned by DNS with the address family shown in logs.
- Fix or disable the broken IPv6 path only according to your distribution’s networking policy.
- Ensure firewall rules cover the selected family and UDP 123.
10. Verify the fix after reboot and normal load
- Reboot during a maintenance window.
- Run
timedatectland confirmSystem clock synchronized: yesafter the client has polled. - Run
chronyc trackingand verify a valid reference, a bounded offset, and a frequency value, or inspecttimedatectl timesync-statuswhen using timesyncd. - Run
chronyc sources -vand confirm that one source is marked^*, other healthy sources are candidates, and Reach is no longer zero. - Repeat the checks after a period of normal VPS activity and after any planned host maintenance.
- Save the service journal and timestamps if the problem returns; those records give the provider evidence of whether the guest stopped receiving replies or the host clock changed.
If synchronization repeatedly fails only after provider maintenance or suspension, open a provider ticket with the exact UTC times, selected source, Reach values, firewall policy, and relevant journal lines. That information distinguishes a guest configuration error from a host-time or network fault.
Frequently asked questions
Can I run chrony and systemd-timesyncd together for redundancy?
No. They are competing clock managers. Redundancy belongs inside one client’s source list, not in multiple daemons issuing corrections at the same time.
Do I need to open inbound UDP 123 on my VPS?
A client normally needs outbound UDP 123 and permitted return traffic. Inbound service access is required only if you intentionally operate an NTP server, which is a different configuration and security decision.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Repair Windows errors before they cause bigger problemsFix Now →Why does ping work while NTP times out?
Ping uses ICMP, whereas NTP uses UDP 123. Separate firewall, security-group, routing, and remote-service policies can allow one while blocking the other.
How many time servers should a VPS use?
The chrony project’s current FAQ guidance is at least three servers for reliable operation. A provider’s documented local source can be included alongside additional trustworthy sources when supported.
Should I force a manual time correction whenever the offset is large?
Prefer the client’s startup step policy, such as chrony’s makestep, and let the daemon manage the correction. Repeated manual changes while synchronization is active create competing adjustments and complicate diagnosis.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
