Why is raid not loading?

As an SEO writer, I will provide quick answers to common questions about why Raid may not be loading properly in the opening paragraphs. Raid not loading can be frustrating, but there are usually some simple troubleshooting steps that can get it working again.

Is Raid enabled in BIOS?

One of the most common reasons for Raid not loading is that it is not enabled in the BIOS. Many motherboards have an option to enable or disable Raid that needs to be switched on. If Raid is not enabled in BIOS, the operating system will not detect the Raid array.

To check if Raid is enabled in BIOS:

  • Restart the computer and press the key to enter BIOS, usually Delete or F2.
  • Navigate to the advanced settings.
  • Look for an option called “Raid” or something similar and make sure it is enabled or turned on.
  • Save changes and exit BIOS.

Enabling Raid in BIOS allows the operating system to detect the Raid array and should allow it to load properly.

Are the Raid drivers installed?

If the Raid array is hardware based, using a Raid card or the onboard Raid controller, the proper drivers need to be installed. Without the Raid drivers, the operating system will not know how to communicate with the Raid card.

To check for Raid drivers:

  • Open Device Manager in Windows.
  • Expand the storage controller section.
  • Check if the Raid controller is listed with a yellow exclamation or unknown device.
  • If the Raid card is not listed correctly, the drivers need to be installed.

The Raid drivers should be available from the motherboard or Raid card manufacturer’s website. Download and install the drivers, then restart the computer. Windows should now detect the Raid card and array.

Are all hard drives connected properly?

For the Raid array to function properly, all the member hard drives need to be connected and detected by the operating system. Loose cables or failed drives can cause the Raid to not load.

To confirm all drives are connected:

  • Power off the computer.
  • Open the case and check that all Raid hard drives are plugged into power and data cables properly.
  • Boot into BIOS and check if all drives are detected.
  • Go into Disk Management in Windows and verify each drive shows up.

If any drives are not detected, try reseating the cables or swap to a new cable. If the drive is still not showing up, it likely has failed and needs to be replaced.

Is the Raid array intact?

If any of the hard drives in the Raid array fail, become corrupted, or are disconnected, it can lead to the Raid not loading properly. The array may show as degraded or be completely broken.

To check Raid status:

  • Reboot into the Raid BIOS utility, usually by pressing Ctrl+R or Ctrl+I during boot.
  • View the Raid array information for any errors or warnings.
  • Look for any failed or missing drives.

If the Raid is degraded or drives are missing, the array will need to be rebuilt or recreated before it can load normally again. The failed drives will need to be replaced.

Was the Raid array migrated?

If the Windows installation was moved from one system to another, such as swapped hard drives to a new motherboard, the Raid array may not load properly. Windows stores drivers for the Raid card that won’t match across different hardware.

After migrating, the Raid drivers need to be uninstalled and reinstalled for the new system:

  • Open Programs and Features in the Control Panel.
  • Uninstall the Raid driver and software.
  • Reboot the computer.
  • Install the updated Raid driver for the new motherboard.
  • Restart again and the array should load.

This process reinstalls the drivers to match the new hardware environment so Windows can access the array again.

Is the boot order set correctly?

In order for Windows to load from the Raid array, the boot order needs to be set correctly in BIOS. If the BIOS is trying to boot from another disk or device, it will skip right over the Raid array.

To check the boot order:

  • Access the BIOS settings on startup.
  • Find the boot options.
  • Make sure the Raid array or controller is the first option.
  • Save changes and restart.

With the Raid array or controller set as primary, the system should detect it on boot and load properly.

Is there an option ROM conflict?

Sometimes having multiple option ROMs enabled in BIOS, such as onboard audio, LAN or Raid, can cause conflicts. This could prevent the Raid option ROM from loading during boot.

Try disabling other option ROMs:

  • Boot into BIOS and locate peripheral option ROMs.
  • Disable or set to legacy any options not needed for booting.
  • The Raid controller ROM may need to be set as the only enabled option.
  • Save changes and exit BIOS.

Resolving the option ROM conflict should allow the Raid card’s BIOS to take control during boot so the array loads.

Was the Raid recently created or rebuilt?

Right after creating a new Raid array or rebuilding the array after a failed drive, it can take time for the metadata and file tables to fully build. This can temporarily cause the array not to be accessible or load right away.

To resolve, allow time for the Raid to finish building in the background:

  • Leave the computer powered on for several hours after Raid creation.
  • Avoid restarting or disconnecting drives to give it time to stabilize.
  • The Raid BIOS utility may show background initialization in progress.
  • Check back after a few hours, the array should be accessible.

Giving the Raid rebuild time to complete will take care of any temporary loading issues in new arrays.

Is the Raid controller faulty?

In rare cases, hardware problems with the physical Raid controller could prevent the array from being detected properly. Errors or a fully failed controller chipset can block access.

To test the Raid card:

  • Move the hard drives to a different system with a known working controller.
  • See if the array will load there.
  • Or swap in a different Raid controller and check if the drives are detected.

If the drives work in another system, the original Raid card likely failed and needs to be replaced. Match it with the same model or chipset for compatibility.

Was there a power failure during use?

If power to the computer is interrupted unexpectedly while the Raid array is running, such as from a blackout or disconnecting the power cable, it can corrupt data in the filesystem.

To fix corruption from power failure:

  • Restart the computer and enter the Raid management utility.
  • Perform a file system check to scan for and repair errors.
  • Allow time for repairs which could be hours for larger arrays.
  • Restart again once completed, the Raid should load normally.

Running a full file system check will identify and resolve any filesystem corruption that is preventing the Raid from loading after abrupt power loss.


Raid arrays failing to load on startup is disruptive but the cause is usually one of several common issues. Checking that the Raid is enabled in BIOS, the controllers drivers are installed, all hard drives are connected, and the boot order is correct can quickly resolve many loading problems. For hardware failures or corrupted arrays, additional troubleshooting steps like replacing drives or controllers may be needed. But being methodical to pinpoint the exact cause will get Raid up and running again.

Issue Troubleshooting Steps
Raid disabled in BIOS Enable Raid in BIOS settings
Missing Raid drivers Install or update Raid controller drivers
Loose drive connections Reseat cables, replace faulty drives
Degraded or failed array Rebuild array with replacement drives
Incorrect boot order Set Raid first in boot options
Raid card option ROM conflict Disable other option ROMs in BIOS
Array not finished building Allow time for initialization to complete
Faulty Raid controller Replace failed controller
File system corruption Run file system check and repairs

This table summarizes some common Raid loading issues and steps to resolve them. Diagnosing the specific problem is key to getting the array back up and running.

When to seek professional help

While most minor Raid problems can be fixed with basic troubleshooting, there are a few instances where assistance from a professional may be needed:

  • Multiple failed hard drives – If more than 1-2 drives fail, repairs become more complex.
  • Advanced Raid setups – For large scale enterprise arrays, specialized tools and knowledge is useful.
  • Mechanical problems – Loose controller slot, component damage may require technical expertise.
  • Extensive data loss or corruption – Severe file system errors could require data recovery services.
  • Time constraints – Professionals can diagnose and repair issues much quicker than DIY.

Seeking help from qualified computer technicians or managed IT services can get Raid restored and prevent data loss when facing complex multi-drive failures or hardware faults.

How to prevent Raid failures

While occasional issues are expected with any storage system, there are ways to minimize problems and improve Raid resilience:

  • Use enterprise-grade hardware – Server-class Raid cards, drives and cases improve reliability.
  • Enable monitoring tools – Remote monitoring software can provide early warning of drive failures.
  • Ensure proper ventilation – Keep drives cool to prevent overheating and early faults.
  • Use UPS battery backup – Protects against corruption from power failures.
  • Regularly backup data – Prevents data loss if array recovery is not possible.
  • Verify cabling and connections – Snug fittings reduce risk of disconnects.
  • Check array health monthly – Fix problems early before multiple drive failures.
  • Consider hot spares – Extra standby drives allow automatic rebuilds.

A little preventative maintenance goes a long way for maximizing Raid uptime. But even with best practices, issues will crop up requiring attentive troubleshooting to get arrays loaded properly.

Frequently asked questions

Why does my Raid keep not loading on reboot?

If the issue is happening consistently on reboots, some of the most common culprits are Raid disabled in BIOS, loose drive connections, drive failures, or incorrect boot order. Checking those items first can often resolve repetitive loading failures.

Can I rebuild a Raid array with different sized drives?

Generally rebuilding a Raid with different drive sizes is not recommended. For Raids like RAID 0, 1, 5 and 10, all drives must be the same size for proper operation. Occasionally a larger drive can be substituted if absolutely necessary, but capacity will match the smallest drive.

How long does it take to rebuild a failed hard drive?

Rebuilding after a failed drive can take hours or longer depending on the array size and controller speed. As a rough estimate, expect 1-2 hours per TB of capacity. So a 4 TB array could take 4-8 hours to fully rebuild onto a new drive.

Can I boot from a Raid 0 array?

Yes, Raid 0 arrays can be bootable and often improve startup speeds compared to a single disk. The operating system files just need to be installed on the Raid 0 drives properly. Just be aware that data is at higher risk since Raid 0 does not have redundancy.

Do all hard drives in a Raid 5 array need to be the same size?

For optimal performance, it is highly recommended all drives are identical capacity in a Raid 5 array. The controller can compensate somewhat for size differences, but overall space will be limited to the smallest drive. Mixing drive sizes also splits data unevenly.

If my motherboard supports Raid, do I still need a controller card?

In most cases the integrated Raid controller in a consumer motherboard is sufficient, so no separate card is needed. But for mission critical setups, a dedicated hardware Raid card can provide better performance and reliability than the onboard controller.

In summary

Getting Raid arrays to load properly again after failures involves methodical troubleshooting to identify the root cause. Before undertaking complex repairs, try simpler steps like checking BIOS settings, drive connectivity, boot order and option ROMs. Seek professional assistance for repairs beyond DIY skills. And be proactive with preventive Raid maintenance to minimize downtime and data loss.

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