lima-vm/lima · critical

reading volume omap: %w

Error message

reading volume omap: %w

What it means

Once findVolume locates the volume superblock matching the requested role, it reads that volume's omap block (physical address from apfsOmapOIDOff) to obtain the omap B-tree root address. This error wraps the readBlock failure for that block. It indicates the volume superblock was found but its omap could not be read.

Source

Thrown at pkg/apfs/chown.go:278

		if err != nil {
			continue // skip volumes we can't resolve
		}
		volBlock, err := c.readBlock(volPhysAddr)
		if err != nil {
			continue
		}
		if verifyChecksum(volBlock) != nil {
			continue
		}
		if le.Uint32(volBlock[apfsMagicOff:]) != apfsMagic {
			continue
		}
		volRole := le.Uint16(volBlock[apfsRoleOff:])
		if volRole == role {
			omapAddr := le.Uint64(volBlock[apfsOmapOIDOff:])
			omapBlock, err := c.readBlock(omapAddr)
			if err != nil {
				return nil, fmt.Errorf("reading volume omap: %w", err)
			}
			return &volumeInfo{
				omapTreeAddr: le.Uint64(omapBlock[omapTreeOIDOff:]),
				rootTreeOID:  le.Uint64(volBlock[apfsRootTreeOIDOff:]),
				latestXID:    le.Uint64(volBlock[objXIDOff:]),
			}, nil
		}
	}
	return nil, fmt.Errorf("no volume with role %#x found", role)
}

// omapLookup searches the omap B-tree for a virtual OID, returning
// the physical address from the entry with the highest xid <= maxXID.
func (c *container) omapLookup(omapTreeAddr, oid, maxXID uint64) (uint64, error) {
	blk, err := c.readBlock(omapTreeAddr)
	if err != nil {
		return 0, err
	}

View on GitHub (pinned to dd909d0973)

Solutions

1. Check the image is complete (size matches the source disk capacity).
2. Try a different volumeRole if the wrong volume was targeted and its storage was trimmed.
3. Run fsck_apfs against the image from a macOS host to repair volume metadata.
4. Re-take the disk image from a cleanly shut-down VM.
5. Restore the image from backup if corruption is confirmed.

if err := apfs.Chown(diskPath, role, uid, gid, paths...); err != nil {
	if strings.Contains(err.Error(), "reading volume omap") {
		log.Warn("target volume omap unreadable; image may be truncated or volume removed")
		return err
	}
	return err
}

When it happens

Trigger: The volume's omap physical address is out of range for the image file, the image is truncated, or an I/O error (bad sector, permission) occurs while reading that specific block.

Common situations: Incomplete disk image copies, corrupted volumes inside an otherwise readable container, or images where the target volume was deleted and its omap blocks were reused/trimmed.

Related errors

• read block 0: %w
• reading container superblock: %w
• resolving filesystem root tree OID %d: %w
• resolving path %#q: %w
• chown inode %d (%#q): %w

AI-assisted analysis of lima-vm/lima@dd909d0973 (2026-09-01). Data as JSON: /api/errors/10933319185504eb. Report an issue: GitHub.