Loading...
Loading...
Observed VMkernel warnings: The following messages appear in the ESXi 9.0 VMkernel log when a virtual disk is created on 512e and or 4Kn formatted hard drives managed by PERC12 or PERC13 controllers. Mode Sense command reports a block size of 0, which does not match the current logical block size of 4096. The device identifier naa. [GUID] is marked as format corrupt. These warnings are logged: Immediately after the virtual disk is created. During every subsequent ESXi boot while the virtual disks remain present. The warnings do not appear when non‑RAID (pass‑through) drives are used. PERC12 and PERC13 Virtual Disks are always created with a 4k sector size regardless of the physical sector size of the drive members. Drive configured as Non‑RAID (pass‑through) drives always pass‑through retaining their original physical sector size. Note: HBA465i and HBA465e controllers are not impacted because they only support Non-RAID drives. Impacted controllers: H965i Front, H965i Adapter, H965i MX and H965e Adapter, H365i Front, H365i Adapter, and H975i Front Impacted OS and Drivers : ESXi 9.0 and 8.11.6.0.0 and later
Mode Sense Command Returns Multiple Block Sizes. The SCSI MODE SENSE command reports both the current block size and the list of possible block sizes supported by a hard drive. When a drive supports both 512e and 4Kn, the response includes descriptors for each block size. Hard drives with dual‑mode support (512e or 4Kn) provide multiple block‑size entries in the MODE SENSE data. PERC12 and PERC13 controllers are designed to handle only a single block size per virtual disk (VD), which is 4k. The mismatch between the controller’s single‑block‑size expectation and the drive’s multi‑block‑size response triggers kernel warnings but no functional impact. Resulting Kernel Warning Messages:Mode Sense cmd reported block size 0, does not match the current logical block size 4096 The device naa. is marked format corrupt
The Fix is added in PERC firmware version 8.16, released in May 2026. With this fix, the corrupt format and block size mismatch messages are no longer displayed.
Click on a version to see all relevant bugs
Dell Integration
Learn more about where this data comes from
Bug Scrub Advisor
Streamline upgrades with automated vendor bug scrubs
BugZero Enterprise
Wish you caught this bug sooner? Get proactive today.