Shulou(Shulou.com)06/02 Report--

After Solaris 9, in order to support storage devices with a capacity greater than 1 TB, a new EFI (Extensible Firmware Interface) type disk label is introduced in disk management. It is very different from the traditional VTOC (Volume Table of Contents) label. We can use the format-e command, and then use the label command to see the type menu for selecting label. The traditional VTOC label is called SMI in format > label.

Compared with VTOC Label, the main differences of EFI Label are as follows:

Can support disks with a capacity greater than 1 TB (including logical disks such as disk arrays).

The partition mode has been changed, and the available partition is slices 0-6, of which 2 partition is also a normal available partition.

One partition must not overlap with other partition slices or label slices (backup label). EFI label occupies 34 sectors (sector), so the starting sectors of other partitions must start with sector 34. That is, partitions starting with sector 0 no longer exist.

EFI label does not save the disk's cylinder, head, and sector information. So when using EFI label, it is operated by the sector number, and the partition size is represented by "block".

The disk information was originally saved in the spare cylindrical area (alternate cylinders area, the last two cylinders of the disk), and the EFI label was saved in slice 8.

When you use the format tool to modify partition, all partitions with zero size are automatically labeled "unassigned" (tag), and partitions with non-zero size are given the default label "usr". After the partition is divided, you can use the partition > change menu to modify the partition label with non-zero capacity (but not the "unassigned" tag).

EFI Label has some limitations. Therefore, you should consider whether disks larger than 1TB (and logical disks) should be used in the application environment based on the following limitations. If you don't want to be limited by EFI label, you should not use a disk larger than 1TB (in the case of an array logical disk, you should reduce the logical disk capacity). The main limitations of EFI Label are:

The current SCSI driver (ssd) only supports a maximum of 2 TB capacity. If you need a capacity greater than 2 TB, you should use a storage management tool such as Solaris Volume Manager to create a high-capacity device.

Some Layered software products, although they claim to support EFI-labeled disks, may not be able to access EFI label disks correctly in practice.

EFI label is not recognized by previous Solaris versions.

EFI label does not support IDE disks.

EFI label disk cannot be used as boot disk.

Solaris Management Console's Disk Manager tool cannot manage EFI label disks, so you can only use format tools to partition EFI label disks, and then use Solaris Management Console's Enhanced Storage tools to manage volumes (volume) or disk packages (disk set) on EFI label disks.

Overlapping partitions cannot be used in EFI, so the original 2 partition no longer represents the whole picture. At this point, the overall representation method is cxtydz.

The parameters such as cylinder and head no longer appear in the capacity information of EFI label disk or partition, but use sectors or blocks as units.

For EFI lab disks, some of the options / subcommands in the format tool are no longer available:

The-save option is not supported because records in format.dat are no longer required for EFI label disks.

The-backup option is not available because the disk drive can write it back to disk when it finds primary label (the steps are completely different from the VOTC method)

Let's take a look at a practical example of EFI label.

Example 1. Full copy of EFI label disk

In the original VTOC approach, partition 2 (S2) represents the whole, so engineers are used to using dd for full replication:

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

The copy of the EFI label disk is different. One is that the EFI label does not have S2, and the other is that there is a UUID (Universally Unique Identifer) on the EFI label disk. Direct replication will lead to duplicate UUID of the two disks. Some software products will have data problems when reading the duplicate UUID, so it is necessary to regenerate the UUID after replication.

Look at the example:

1. Complete data cloning first:

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

two。 Direct the prtvtoc output of the source disk to the fmthard command to generate a new label of the target disk:

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

Example 2. Create an EFI or SMI label

For disks smaller than 1TB, you can use either VTOC label or EFI label. If you use a regular format command with no parameters, if the original disk has been label, the original label type will not be changed; if there is no label, you will be prompted to label and use the regular VTOC type. If you need to choose to specify the label type, or if you need to change the original label type, you can use the format-e parameter.

The familiar prompt for the regular format > label command is as follows:

# format

Searching for disks...done

……

Format > lable

Ready to label disk, continue?

The format > label command with the-e argument looks like this:

# format-e

Searching for disks...done

……

Format > label

[0] SMI Label

[1] EFI Label

Specify Label type [0]: 0

Ready to label disk, continue?

A selection menu of type label is provided above.

Example 3. Using the format tool, a 1.15 TB EFI label disk is divided into three sections.

# format

……

Partition > modify

Select partitioning base:

0. Current partition table (original)

1. All Free Hog

Choose base (enter number) [0]? 1

Part Tag Flag First Sector Size Last Sector

0 root wm 0 0 0

1 usr 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 usr wm 0 0 0

8 reserved wm 2576924638 8.00MB 2576941021

Do you wish to continue creating a new partition

Table based on above table [yes]? Y

Free Hog partition [6]? 4

Enter size of partition 0 [0b, 34e, 0mb, 0gb, 0tb]:

Enter size of partition 1 [0b, 34e, 0mb, 0gb, 0tb]:

Enter size of partition 2 [0b, 34e, 0mb, 0gb, 0tb]: 400gb

Enter size of partition 3 [0b, 838860834e, 0mb, 0gb, 0tb]: 400gb

Enter size of partition 5 [0b, 1677721634e, 0mb, 0gb, 0tb]:

Enter size of partition 6 [0b, 1677721634e, 0mb, 0gb, 0tb]:

Part Tag Flag First Sector Size Last Sector

0 unassigned wm 0 0 0

1 unassigned wm 0 0 0

2 usr wm 34 400.00GB 838860833

3 usr wm 838860834 400.00GB 1677721633

4 usr wm 1677721634 428.77GB 2576924637

5 unassigned wm 0 0 0

6 unassigned wm 0 0 0

8 reserved wm 2576924638 8.00MB 2576941021

Ready to label disk, continue? Yes

Partition > Q

Example 4. Display disk label information

# prtvtoc / dev/rdsk/c0t0d0s0

* / dev/rdsk/c0t0d0s0 partition map

*

* Dimensions:

* 512 bytes/sector

* 63 sectors/track

* 15 tracks/cylinder

* 945 sectors/cylinder

* 8894 cylinders

* 8892 accessible cylinders

*

* Flags:

* 1: unmountable

* 10: read-only

*

* First Sector Last

* Partition Tag Flags Sector Count Sector Mount Directory

0 2 00 1048950 3381210 4430159 /

1 3 01 0 1048950 1048949

2 5 00 0 8402940 8402939

78 00 4430160 3972780 8402939 / export/home

This is a VTOC label disk.

# prtvtoc / dev/rdsk/c3t1d0s0

* / dev/rdsk/c3t1d0s0 partition map

*

* Dimensions:

* 512 bytes/sector

* 2479267840 sectors

* 2479267773 accessible sectors

*

* Flags:

* 1: unmountable

* 10: read-only

*

* First Sector Last

* Partition Tag Flags Sector Count Sector Mount Directory

0 2 00 34 262144 262177

1 3 01 262178 262144 524321

6 4 00 524322 2478727100 2479251421

8 11 00 2479251422 16384 2479267805

This is an EFI label disk.

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