SPARC: Multiterabyte Volume Support With EFI Disk Label

This Solaris release provides support for disks that are larger than 1 terabyte on systems running a 64-bit Solaris kernel. The Extensible Firmware Interface (EFI) disk label is not available for disks connected to a system running a 32-bit Solaris kernel, such as a system running the Solaris x86 Platform Edition.

You can download the EFI specification at http://www.intel.com/technology/efi/main_specification.htm.

The EFI label provides support for physical disks and virtual disk volumes. This release also includes updated disk utilities for managing disks greater than 1 terabyte. The UFS file system is compatible with the EFI disk label, and you can create a UFS file system greater than 1 terabyte. For information on creating a multiterabyte UFS file system, see SPARC: Support of Multiterabyte UFS File Systems.

The Solaris Volume Manager software can also be used to manage disks greater than 1 terabyte in this Solaris release. For information on using Solaris Volume Manager, see Solaris Volume Manager Administration Guide.

The VTOC label is still available for disks less than 1 terabyte in size. If you are only using disks smaller than 1 terabyte on your systems, managing disks will be the same as in previous Solaris releases. In addition, you can use the format-e command to label a disk less than 1 terabyte with an EFI label. For more information, see Example—Labeling a Disk Less Than 1 Terabyte with an EFI Label.

Comparison of the EFI Label and the VTOC Label

The EFI disk label differs from the VTOC disk label in the following ways:

• Provides support for disks greater than 1 terabyte in size.

• Provides usable slices 0–6, where slice 2 is just another slice.

• Partitions (or slices) cannot overlap with the primary or backup label, nor with any other partitions. The size of the EFI label is usually 34 sectors, so partitions start at sector 34. This feature means no partition can start at sector zero (0).

• No cylinder, head, or sector information is stored in the label. Sizes are reported in blocks.

• Information that was stored in the alternate cylinders area, the last two cylinders of the disk, is now stored in slice 8.

• If you use the format utility to change partition sizes, the unassigned partition tag is assigned to partitions with sizes equal to zero. By default, the format utility assigns the usr partition tag to any partition with a size greater than zero. You can use the partition change menu to reassign partition tags after the partitions are changed. However, you cannot change a partition with a non-zero size to the unassigned partition tag.

Restrictions of the EFI Disk Label

Keep the following restrictions in mind when determining whether to use disks greater than 1 terabyte is appropriate for your environment:

• The layered software products intended for systems with EFI-labeled disks might be incapable of accessing a disk with an EFI disk label.

• A disk with an EFI disk label is not recognized on systems running previous Solaris releases.

• The EFI disk label is not supported on IDE disks.

• You cannot boot from a disk with an EFI disk label.

• You cannot use the Solaris Management Console's Disk Manager Tool to manage disks with EFI labels. Use the format utility or the Solaris Management Console's Enhanced Storage Tool to manage disks with EFI labels, after you use the format utility to partition the disk.

• The EFI specification prohibits overlapping slices. The whole disk is represented by cxtydz.

• UFS file systems are compatible with the EFI disk label. Starting in the Solaris 9 8/03 release, you can create a UFS file system that is greater than 1 terabyte. For more information multiterabyte UFS file systems, see SPARC: Support of Multiterabyte UFS File Systems.

  The unbundled Sun QFS file system is also available if you need to create file systems greater than 1 terabyte. For information on the Sun QFS file system, see http://docs.sun.com/db/doc/816-2542-10.

• Provides information about disk or partition sizes in sectors and blocks, but not in cylinders and heads.

• The following format options are either not supported or are not applicable on disks with EFI labels:

  • The save option is not supported because disks with EFI labels do not need an entry in the format.dat file.

  • The backup option is not applicable because the disk driver finds the primary label and writes it back to the disk.

Installing a System With an EFI-Labeled Disk

The Solaris installation utilities automatically recognize disks with EFI labels, but cannot use the Solaris installation utilities to repartition these disks. You must use the format utility to repartition this disk before or after installation. The Solaris Upgrade and Live Upgrade utilities also recognize a disk with an EFI label. However, you cannot boot a system from an EFI-labeled disk.

After the Solaris release is installed on a system with an EFI-labeled disk, the partition table looks similar to the following:

Current partition table (original):
Total disk sectors available: 2576924638 + 16384 (reserved sectors)

Part      Tag    Flag     First Sector          Size          Last Sector
  0       root    wm                34         1.20TB           2576924636
  1 unassigned    wm                 0            0                0    
  2 unassigned    wm                 0            0                0    
  3 unassigned    wm                 0            0                0    
  4 unassigned    wm                 0            0                0    
  5 unassigned    wm                 0            0                0    
  6 unassigned    wm                 0            0                0    
  8   reserved    wm        2576924638         8.00MB           2576941021   

Managing Disks With EFI Disks Labels

Use the following table to locate information on managing disks with EFI disk labels.

Cloning a Disk with an EFI Label

In previous Solaris releases, slice 2 (s2) was used to represent the whole disk. You could use the dd command to clone or copy disks by using syntax similar to the following:

dd if=/dev/rdsk/c0t0d0s2 of=/dev/rdsk/c0t2d0s2 bs=128k

Now, you must use a slightly different procedure to clone or copy disks larger than 1 terabyte so that the UUID of cloned disks are unique. For example:

1. Use the dd command to clone the disk with an EFI label:

   # dd if=/dev/rdsk/c0t0d0 of=/dev/rdsk/c0t2d0 bs=128k

2. Pipe the prtvtoc output of the disk to be copied to the fmthard command to create a new label for the cloned disk.

   # prtvtoc /dev/rdsk/c0t0d0 | fmthard -s - /dev/rdsk/c0t2d0

If you do not create a new label for the cloned disk, other software products might corrupt data on EFI-labeled disks if they encounter duplicate UUIDs.

Troubleshooting Problems With EFI Disk Labels

Use the following error messages and solutions to troubleshooting problems with EFI-labeled disks.

Error Message

Dec 3 09:26:48 holoship scsi: WARNING: /sbus@a,0/SUNW,socal@d,10000/ sf@1,0/ssd@w50020f23000002a4,0 (ssd1): Dec 3 09:26:48 holoship disk has 2576941056 blocks, which is too large for a 32-bit kernel

Cause

You attempted to boot a system running a 32-bit SPARC kernel with a disk greater than 1 terabyte.

Solution

Boot a system running a 64-bit SPARC kernel with a disk greater than 1 terabyte.

Error Message

Dec 3 09:12:17 holoship scsi: WARNING: /sbus@a,0/SUNW,socal@d,10000/ sf@1,0/ssd@w50020f23000002a4,0 (ssd1): Dec 3 09:12:17 holoship corrupt label - wrong magic number

Cause

You attempted to add this disk to a system running an older Solaris release.

Solution

Add this disk to a system running the Solaris release that supports the EFI disk label.