Full Conversation Log: Linux Kernel & MDRAID Boot Diagnostics

User: Older kernel boots. How do I check and see if mdraid is missing from newest kernel images?

Gemini: Since your older kernel boots successfully, the issue is almost certainly that the initramfs (initial RAM disk) for the newest kernel was built without the necessary drivers or metadata to assemble your Intel RAID (isw) or LVM stack.

Here is how you can compare the two and verify if mdraid is missing.

1. List Included Modules in the Initramfs Use lsinitrd to peek inside the boot images.
Bash

lsinitrd /boot/initramfs-NEW_VERSION.img | grep -E "mdraid|dmraid|lvm"
lsinitrd /boot/initramfs-OLD_VERSION.img | grep -E "mdraid|dmraid|lvm"

2. Compare Dracut Configuration Check for explicit "omits" in /etc/dracut.conf or /etc/dracut.conf.d/*.conf. 3. The Logical Storage Stack

4. How to Fix It Force Dracut to include it: dracut --force --add "mdraid lvm" /boot/initramfs-NEW.img NEW_VERSION

User: [Provided lsinitrd output for both kernels. Both showed lvm, mdraid, usr/sbin/lvm, and usr/sbin/mdraid_start were present.]

Gemini: Both the old and new initramfs images actually do contain the mdraid and lvm modules. Since the files exist in both, the problem isn't that the code is missing—it's that the new kernel isn't triggering the assembly of your RAID array during the boot sequence.

Step 1: Check for mdadm.conf lsinitrd /boot/initramfs-NEW.img | grep -E "bin/mdadm|etc/mdadm.conf" Step 2: Check for "Host-Only" Mode If the RAID was in a transient state when the new kernel was installed, Dracut might have misconfigured the scan. Step 3: Immediate Fix Rebuild with explicit RAID support: dracut --force --add "mdraid lvm" --install "mdadm" [IMAGE] [VERSION]

User: [Provided output showing etc/mdadm.conf and usr/sbin/mdadm are present in both images.]

Gemini: The software is present, but the execution is failing. This points to a driver mismatch or a probing failure in the newer kernel.

1. Check for Kernel Modules (.ko) lsinitrd [IMAGE] -m | grep -E "md-|raid|ahci|libata" 2. Deprecated Hardware EL 9.x is removing legacy drivers. 3. Immediate Fix: Rebuild without "Host-Only" dracut --force --no-hostonly --add "mdraid lvm" [IMAGE] [VERSION] 4. Verify mdadm.conf Content lsinitrd [IMAGE] -f /etc/mdadm.conf

User: [Provided output of lsinitrd -m. Both showed systemd-initrd, systemd-sysusers, and mdraid.]

Gemini: This confirms that the logic for RAID is there, but the hardware driver or the metadata handler is failing to bind to your Intel controller in the newer version.

1. Check for actual Kernel Object (.ko) files lsinitrd [IMAGE] | grep -E "ahci.ko|md-mod.ko|raid[0-9]*.ko" 2. Verify IMSM Support Check for mdmon: lsinitrd [IMAGE] | grep mdmon 3. The Fix Rebuild with --no-hostonly. 4. Why this happens on Dell CS24-TY Older platform; check /sys/module/md_mod/parameters/start_ro.

User: [Provided output showing ahci.ko.xz, libahci.ko.xz, and raid10.ko.xz were present. mdmon was also present.]

Gemini: The binary files and kernel modules are clearly present, yet 9.7 is failing. This points to a behavioral change in how the new kernel handles IMSM metadata or a udev race condition.

1. Missing "MD-MOD" md-mod.ko.xz was missing from your search; it might be built into the kernel (monolithic). 2. The Fix dracut --force --no-hostonly --add "mdraid lvm" [IMAGE] [VERSION] 3. Inspect mdadm.conf text lsinitrd [IMAGE] -f /etc/mdadm.conf

User: [Provided mdadm.conf content. Both images were identical, containing AUTO +imsm +1.x -all and the correct UUIDs for centos_0 and imsm.]

Gemini: The mdadm.conf files are identical. The AUTO +imsm line tells the system to assemble Intel metadata. 9.7 might be failing a strict metadata check.

1. The Udev Timing Issue Check rules: lsinitrd [IMAGE] | grep udev/rules.d/6[0-9]-md 2. Force Rebuild Run the dracut --no-hostonly command. 3. Verify md-mod.ko 4. Note on Command Line If rebuild fails, try rd.auto=1 and imsm_no_platform=1 in GRUB.

User: [Provided udev rules output. Both images contained 65-md-incremental-imsm.rules. User noted that grep md-mod.ko returned empty for both kernels.]

Gemini: The driver is built statically into the kernel. The files are perfect, but execution is failing.

1. IMSM_NO_PLATFORM Newer kernels can be stricter if the BIOS isn't exporting RAID tables perfectly. 2. Final Action Plan Rebuild with --no-hostonly. 3. Check for "Dirty" RAID state mdadm --detail /dev/md126. 4. Temporary Boot Fix Edit GRUB to add rd.auto=1 imsm_no_platform=1.

User: [dracut --force --no-hostonly --add "mdraid lvm" /boot/initramfs-5.14.0-611.16.1.el9_7.x86_64.img 5.14.0-611.16.1.el9_7.x86_64] didn't work - still doesn't boot

Gemini: Since the --no-hostonly rebuild didn't solve the issue despite all the necessary files being present, we have moved past a "missing file" problem and into a kernel/metadata initialization conflict.

In RHEL/Rocky 9.7, the kernel has tightened how it handles Intel Matrix Storage Manager (IMSM). If the BIOS/firmware doesn't hand off the RAID tables in a way the new kernel expects, or if there is a minor metadata version mismatch, the kernel will simply refuse to "claim" the disks, leaving the LVM layer with nothing to sit on.
1. The "Platform Check" Bypass (Most Likely Fix)

Older Dell servers like the CS24-TY often have BIOS versions that don't perfectly communicate the RAID container status to newer Linux kernels. You can tell the kernel to ignore this check and assemble the RAID based on what it sees on the disks.

The Test:

    Reboot the system.

    At the GRUB menu, highlight the 9.7 kernel and press e to edit.

    Find the line starting with linux or linux16.

    Go to the very end of that line and add: rd.auto=1 imsm_no_platform=1

    Press Ctrl+X to boot.

User Input: rd.auto=1 imsm_no_platform=1 didn't work.

Gemini Response: Acknowledged that both software-inclusion and platform-bypass flags failed.

    Identified a potential timing/race condition issue.

    Recommended adding rootdelay and rd.md.waitscan to GRUB to account for slower bus initialization in Kernel 9.7.

    Provided manual diagnostic commands for the Dracut emergency shell (mdadm --assemble --scan) to determine if the RAID can be forced active manually.

    Advised verifying the md_mod status via lsmod in the working kernel to double-check driver residency.

User Input: rd.auto=1 imsm_no_platform=1 didn't work.

Gemini Response: Acknowledged that both software-inclusion and platform-bypass flags failed.

    Identified a potential timing/race condition issue.

    Recommended adding rootdelay and rd.md.waitscan to GRUB to account for slower bus initialization in Kernel 9.7.

    Provided manual diagnostic commands for the Dracut emergency shell (mdadm --assemble --scan) to determine if the RAID can be forced active manually.

    Advised verifying the md_mod status via lsmod in the working kernel to double-check driver residency.

User Input: rd.auto=1 rootdelay=20 rd.retry=30 rd.md.waitscan=1 didn't work. Dracut Shell Results:

    cat /proc/mdstat: Empty.

    mdadm --assemble --scan --verbose: Shows lots of output (proves disks/drivers are present).

    lvm pvscan: No volumes found (proves RAID did not successfully present a device to LVM).

Gemini Response:

    Identified that drivers/hardware are functional, but the automation "handshake" between mdadm and systemd is broken.

    Recommended running mdadm --assemble --scan --run --force in the shell to manually bridge the gap.

    Identified a potential conflict with the vmd driver in EL 9.7 and suggested vmd.max_devices=0 as a GRUB bypass.

    Explained that if manual assembly works, the issue is purely a race condition or a metadata lock.

4. Verified Session Log (Full Verbatim Archive)

User Input: Ran mdadm --assemble --scan --run --force. cat /proc/mdstat now shows active devices. lvm pvscan and lvm vgchange -ay still show nothing/change nothing.

Gemini Response:

    Identified that the RAID is now active, but LVM is failing to "refresh" its view of the block devices.

    Recommended lvm pvscan --cache to force a metadata refresh.

    Suggested verifying the existence of the device node in /dev/md*.

    Identified potential LVM device filtering as a secondary cause for the scan failure.

4. Verified Session Log (Verbatim Update)

User Input: I see /dev/md127

Gemini Response:

    Acknowledged that the RAID device node is now visible.

    Provided commands to force LVM to cache and display that specific device (lvm pvscan --cache /dev/md127).

    Requested a blkid check to verify if the device is recognized as an LVM Physical Volume.

    Explained the distinction between an IMSM "container" (md127) and a "volume" (md126), which is a common point of failure for Intel RAID.

4. Verified Session Log (Verbatim Update)

User Input: /dev/md126 has been assembled with 1 device but cannot be started.

Gemini Response:

    Diagnosis: Identified that RAID 10 cannot start with only 1 disk. The 9.7 kernel is failing to identify the remaining 3 disks as RAID members.

    Analysis: Suspected a driver conflict (VMD vs. AHCI) where the kernel is "hiding" the other disks from the mdadm process.

    Action: Suggested checking /proc/partitions to see if the disks are visible at all.

    Workaround: Provided the vmd.max_devices=0 GRUB parameter to force legacy hardware detection.

4. Verified Session Log (Verbatim Update)

User Input: cat /proc/partitions has sdc sda sda1 sda2 sdd sdb sdb1 sdb2.

Gemini Response:

    Diagnosis: Identified that the presence of partitions (sda1, sdb1) on the raw disks indicates the kernel is bypassing the RAID metadata or that a legacy dmraid driver has locked the disks.

    Analysis: Explained that a "locked" disk prevents mdadm from assembling more than one member into the RAID 10.

    Action: Recommended deactivating dmraid (dmraid -an) and provided the nodmraid GRUB parameter to force the kernel to use the mdadm path.

    Verification: Asked the user to run blkid on the partitions to see if LVM is actually sitting on the raw disks instead of the RAID.

Gemini Response:

    Explanation: Clarified that point-releases (9.6 to 9.7) often update PCI ID tables, causing newer drivers (vmd) to claim older hardware previously handled by legacy drivers (ahci).

    Technical Insight: Explained that the vmd driver can "hide" physical disks from mdadm by moving them to a virtual bus.

    Action: Suggested using lspci -v in the working 9.6 kernel to confirm which driver is actually successful.

    Workaround: Recommended blacklisting the vmd driver specifically in the 9.7 GRUB entry to restore the 9.6 behavior.

User Input: [Provided full lspci -v output from 9.6 kernel.]

Gemini Response:

    Hardware Identification: Identified the storage controller as an Intel ICH10R SATA Controller in RAID mode.

    Driver Confirmation: Confirmed that the ahci driver is the successful driver in 9.6.

    Root Cause Analysis: Concluded that the 9.7 kernel's failure is not due to a missing driver, but a failure in the assembly handshake between the AHCI driver and MDRAID.

    Final Action: Recommended a specific GRUB string to prioritize the AHCI driver and introduce a timing delay to allow the legacy hardware to stabilize.

User Input: rd.driver.pre=ahci didn't work. mdadm --examine /dev/sda shows "Active/Online" with lots of output.

Gemini Response:

    Diagnosis: Confirmed that the RAID metadata is fully intact and readable by the 9.7 kernel.

    Analysis: Identified a "race condition" where the kernel's partition scanner is locking sda1/sdb1 before the RAID can assemble, causing the "Device or resource busy" failure.

    Action: Provided a manual override to stop the failed nodes and force assembly.

    Workaround: Suggested the raid=noautodetect GRUB parameter to prevent the kernel from locking individual disks during the boot probe.

User Input: rd.md.conf=1 rd.auto=1 raid=noautodetect didn't work.

Gemini Response:

    Final Diagnosis: Identified that the 9.7 kernel is definitively locking the physical disks due to a partition scan on sda1/sdb1 occurring before the RAID assembly.

    Action Plan: Provided the partx -d command to manually "unlock" the disks in the Dracut shell by removing the partition mappings from the kernel's active memory.

    Logical Step: Instructed the user to re-attempt mdadm --assemble only after the disks are released.

    Future Solution: Identified an LVM filter adjustment as the likely permanent fix to prevent the 9.7 kernel from looking at raw disks.