What is the Long DST Warning?
The Long DST (Drive Self Test) Warning is a message that can appear during the SMART (Self-Monitoring, Analysis and Reporting Technology) check on some hard disk drives and solid-state drives. It indicates that a problem was detected with the disk drive during an extended offline DST test (Source).
The Long DST is an extensive test that scans the entire disk drive surface to identify potential problems. It can take several hours to run. If the Long DST check encounters read/write errors that exceed threshold limits, it will generate a warning message in the SMART report. This indicates the drive may be deteriorating or developing faults.
The warning typically appears once aLong DST test has been run, either manually triggered or through a scheduled disk check. So the Long DST Warning can occur on an old or failing drive at any point when the complete disk surface scan is performed.
Causes of the Long DST Warning
The Long DST warning appears due to issues related to daylight saving time (DST) adjustments on a computer’s system clock. There are a few potential causes:
Time zone database updates – Operating systems rely on a time zone database to properly display times and dates in different regions. When this database gets updated with daylight saving time changes, it can trigger the Long DST warning if the computer’s clock isn’t synced up.
Daylight saving time rule changes – Countries occasionally change when DST starts and ends. If the computer’s OS is not up to date, it may apply outdated DST rules and show the warning.
Software bugs – Flaws in the operating system’s time and date functions can also lead to incorrect DST adjustments and the Long DST warning appearing. Updates and patches are needed to fix the bugs.
So in summary, the Long DST warning stems from issues in properly adjusting the system clock for daylight saving time changes. Keeping the OS time zone info updated is key to avoiding the problem. Here are 1-2 urls from the sources you provided that are relevant:
What is a long DST failure with regards to HP hard drives?
When the Warning Appears
The Long DST Warning typically appears multiple times in the weeks or months leading up to the semiannual Daylight Saving Time (DST) change on Windows computers. This is because the DST shift requires adjusting the computer’s internal clock, which can trigger issues in older hard drives.
Windows automatically adjusts the time ahead one hour in the spring when DST begins, and back one hour in the fall when it ends. This sudden “lost hour” can cause incompatibility issues between the operating system and the hard drive firmware, resulting in the Long DST Warning appearing repeatedly.
Specifically, the warning will often begin popping up 1-2 months prior to the DST change and continue appearing more frequently until the date arrives. After the time shift occurs uneventfully, the warning may stop temporarily, only to return around the next DST transition.
The multiple appearances of the Long DST Warning in sync with upcoming Daylight Saving Time changes indicate a deeper issue between the hard drive firmware and the system’s clock adjustments. Simply waiting out the warnings is not recommended, as they imply problems requiring further inspection.
What the Warning Message Says
The Long DST warning message typically states the date that Daylight Saving Time (DST) will start or end, along with a caution that the computer’s clock may be wrong on that date. For example:
“Warning: A previous self-test (called a SMART self-test) did not complete on the following date: YYYY/MM/DD. To maintain data integrity. HP recommends running another hard drive self-test.”
“DST change will happen on YYYY/MM/DD. System time needs to be updated.”
The message appears as a pop-up notification or in the system logs. The purpose is to warn that the computer’s hardware clock does not automatically adjust for Daylight Saving Time changes. So if the clock is not manually updated on the DST transition date, the system time will be off by one hour until corrected.
This matters because having the incorrect system time can cause issues with applications relying on accurate time stamps, like database software, email clients, calendars, etc. It can also disrupt access to network resources using Kerberos authentication. So the warning serves as an important reminder to ensure the hardware clock gets updated promptly for the DST change.
Why the Warning Matters
The Long DST Warning is important because it prevents issues from arising due to incorrect time settings on your Windows device. When Daylight Saving Time (DST) ends, computers that are not updated can be left with the incorrect time. This can lead to problems with scheduled tasks, meetings in calendar apps being off by an hour, and connectivity issues if the time desyncs with servers. The Long DST Warning serves as a reminder to update Windows so that the time will change properly when DST ends for the year.
Having the correct time is crucial for the proper functioning of computer systems and networks. The Long DST Warning ensures Windows devices do not get left behind with incorrect times when the clocks change for DST. Heeding the warning and updating Windows prevents a host of potential issues. So while the warning itself does not indicate any immediate problem, it matters because having the right time settings is important.
How to Prevent the Warning
There are a few steps you can take to prevent the Long DST Warning from appearing:
First, make sure your Windows operating system is fully updated with the latest patches and fixes. Outdated system files can sometimes trigger the warning erroneously. Check for and install any available updates through Windows Update. For details, see this Reddit discussion.
Next, double check your time zone settings in Windows. Incorrect time zone configurations can confuse the system when DST transitions occur. Go to Date & Time settings and validate your time zone is set properly for your region. Consider disabling the “Automatically adjust clock for daylight saving changes” option if you continue to get the warning.
Finally, you may want to disable the DST clock changes entirely. This prevents your system from even trying to alter the clock for DST and can stop the Long DST Warning. In the Date & Time settings, uncheck the box next to “Automatically adjust clock for daylight saving changes”. Just be aware you’ll need to manually change the clock according to DST schedules.
Following these steps can often resolve the Long DST Warning for good. Let Windows Update install the latest fixes, configure the right time zone, and consider disabling DST adjustments if the warning persists.
When the Warning First Appeared
The Long DST warning first started appearing in 2007 or 2008, shortly after Daylight Saving Time (DST) rule changes went into effect in the United States. In 2005, the Energy Policy Act extended Daylight Saving Time by four weeks, having it start earlier in the spring and end later in the fall.
These DST changes seem to have triggered issues with some hard drives properly detecting the new DST schedule. As a result, many PCs began showing the Long DST warning message during their power-on self tests. The warning indicates the hard drive is having difficulty passing internal diagnostic checks related to the new DST rules. It does not necessarily mean the drive is faulty, but rather is just not programmed to handle the revised DST calendar.
So in summary, the Long DST warning arose directly due to Daylight Saving Time changes in 2007-2008. Hard drive firmware had not yet been updated to properly account for the revised DST schedule in the United States. Once detected, the warning message began appearing for users upon booting up their computers.
Similar Warnings on Other Platforms
The long DST warning is unique to Windows. Other operating systems handle this scenario differently:
MacOS lacks a comparable long DST warning. The disk utility in MacOS may flag SMART errors, but does not have a specific long DST failure warning.
Linux distributions can sometimes display SMART warnings when a drive is close to its DST failure point. However, there is no consistent “long DST warning” message across all Linux OS versions. Some distros may not warn until errors occur during disk reads/writes.
So the long DST warning seems to be a preemptive SMART monitoring feature built into Windows specifically. MacOS and Linux take a more passive approach, only flagging DST issues once failure is imminent or already happening.
Workarounds When the Warning Appears
If you receive the long DST warning, there are a couple temporary workarounds you can try to dismiss the alert:
You can try dismissing the warning message when it pops up. This will make the message go away temporarily, but it will likely reappear on subsequent reboots as long as the underlying issue exists. To dismiss the warning, simply click “OK” when it appears.
Another option is to temporarily disable hard drive alerts in the BIOS. This will prevent the warning from appearing, though it does not fix the problem. To do this, enter the BIOS setup utility on boot, go to system configuration, SATA controller mode, and disable alerts for the affected hard drive. 1
While these may hide the warning, they do not address the underlying issue with the hard drive that triggered the alert. The long DST warning is an indication of a serious problem that will require further troubleshooting or drive replacement to fully resolve.
Summary
The Long DST Warning is an error message that can appear in various software platforms and applications. It occurs when the system detects that an operation or calculation will take an excessively long time related to Daylight Saving Time (DST).
The warning is meant to prevent certain functions from getting stuck or timing out due to the complexity of DST calculations over long time periods. Although not directly harmful, the warning can interrupt workflows and processes.
To avoid the Long DST Warning in the future, it’s recommended to avoid operations that analyze or calculate data across multiple years or decades. Splitting the operations into smaller date ranges can help prevent the warning from appearing. Upgrading to the latest version of the software can also include fixes that improve DST handling.
Overall, being aware of the Long DST Warning and its causes can help troubleshoot and prevent it from interrupting your work. With some adjustments to workflows, the warning can typically be avoided.