Section 3 - Supplementary Hardware Information
Chapter 9 - Working with Multiple Fixed Disks
Chapter 10 - Using WD1003 Fixed Disks
Chapter 11 - Reconfiguring the Server
Chapter 12 - Using Fixed Disk Utilities
Chapter 13 - Supported Hardware
Chapter 9 - Working with Multiple Fixed Disks
This chapter provides information pertinent to administrators whose servers contain disk arrays (RAID - Redundant Array of Inexpensive Disks), multiple fixed disks, or very large fixed disks (over 2 GB). This chapter covers the following topics:
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Disk configuration terms and concepts ![]()
Logical disk configuration ![]()
Inode allocation ![]()
Disk ordering ![]()
Installing additional fixed disks Note: Banyan server software is installed on /disk1 of your server and not on an additional file systems. Additional file systems and file systems on additional disks can contain Banyan services and the data areas used by those services, such as storage for a file service, but cannot contain the primary server software. Banyan recommends that you use /disk1 for Banyan software only and that you use other files systems (/disk2, /disk3, etc.) for services and data areas. If you follow this recommendation, /disk1 can be a minimum of 150 MB.
Understanding Disk Configuration Concepts
When discussing disk concepts, it is important to distinguish among the terms physical disk, logical disk, and UNIX file system.
A physical disk is a hard disk drive composed of several platters on a single spindle that rotate under several moving heads. The physical disk is formatted into sectors, each capable of storing 512 bytes of data.
A logical disk is a set of 512-byte disk sectors that is addressable by a disk controller through software. For ST506, ESDI, IDE and SCSI fixed disks, a logical disk consists of one physical disk, hence these terms are interchangeable. A disk array (RAID) consists of several physical disks configured as one or more logical disks. For example, a disk array may consist of several physical disks that can be configured using a manufacturer-specific array configuration utility into one or two logical disks. For disk arrays without fault tolerance (RAID 0), the capacity of a logical disk is the sum of the capacities of the physical disks of which it is composed. For disk arrays with fault tolerance (RAID 1, 3, 4, and 5), the capacity of a logical disk is the sum of the capacities of the physical disks minus one physical disk. For RAID 1, the capacity of a logical disk is half the sum of the capacities of the physical disks.
A file system is a logically grouped set of disk sectors that can store files in an operating system. A UNIX file system consists of two major sections; inodes and data blocks. The inodes are a collection of file system blocks that store information about the files in the file system. This file information includes length, location on the disk, and pointers to the data blocks. The data blocks store the actual data that comprises the file as well as blocks composed entirely of pointers to other data blocks. File systems are restricted to a maximum capacity of 16 GB.
At the time of installation, Banyan server software presents you with the total size of a logical disk and gives you the opportunity to create multiple S10 file systems, or partitions, containing up to 16 GB of data on the logical disk. You can specify the size of each file system. Each file system is named /diskn, where n is a number from 1 through 12; for example, /disk1 or /disk6.
The following example of a disk configuration in a computer with disk arrays assumes that the disk arrays have been set to RAID 0 (no fault tolerance).
Example Logical Disk Configuration
For a computer with a 1.3 GB disk drive, Banyan software allows you to create a 50 MB root file system and reserve a 32 MB swap area. The software then will use the approximately 1.2 GB remaining in logical disk 1 to create the file system /disk1. You can override this size and specify the size of the /disk1 file system. Figure 9-1 illustrates the layout of physical disks, logical disks, and file systems for this example.
If you add a RAID 0 disk array with seven 1.3 GB physical disks and configure it as two more logical disks (logical disk 2 - 5.2 GB and logical disk 3 - 3.9 GB), the Banyan server software creates two file systems on these logical disks: /disk2 and /disk3. You can override the creation of these file systems and specify the size of the file systems. For example, you can create three file systems on logical disk 2 of 2.6 GB, 1.3 GB, and 1.3 GB and two file systems on logical disk 3 of 2.0 GB and 1.9 GB. You then have /disk2, /disk3, and /disk4 on logical disk 2, and /disk5 and /disk6 on logical disk 3.
If you add a second RAID 0 disk array with seven 1.3 GB physical disks and configure it as one logical disk (logical disk 4), Banyan server software creates one file system of 9.1 GB in this logical disk. You can override the creation of this file system and specify the sizes of the file systems. For example, you can divide it into five more file systems of equal or unequal size: /disk7, /disk8, /disk9, /disk10, and /disk11.
Use your platform configuration or disk array utility to specify the number of physical disk drives allocated to each logical disk configuration. For more information, refer to the documentation that came with your platform.
For instructions on installing additional disks, refer to "Installing Additional Fixed Disks" later in this chapter.
Banyan supports logical disks up to 26 GB; 20 GB if the disk is the boot drive. For an existing Banyan file system, a root partition of approximately 5.5 MB exists on the physical disk containing /disk1 that contains the UNIX image and system logs and files. In addition, a swap area of approximately 3.9 MB exists on that physical disk.
A fresh installation on a logical disk 1 that does not contain a Banyan file system creates a root partition of 50 MB and reserves a swap area of 32 MB. On a disk that does contain an existing Banyan file system, you can choose to have the larger root file system and swap area created but you must ascertain that your existing /disk1 will fit on the logical disk after you create the larger areas.
Banyan servers use S10 file systems that are created with the following inode algorithm:
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For disks with capacity up to 64 MB, one inode is allocated for every 1 KB of disk capacity. ![]()
For disks with capacity greater than 64 MB and less than 2 GB, 65,536 inodes are allocated for the first 64 MB and, for the disk capacity in excess of 64 MB, one inode is allocated for every 4 KB of disk capacity up to a maximum of 524,264 inodes. ![]()
For disks with capacity greater than 2 GB and less than 16 GB, 524,264 inodes are allocated for the first 2 GB and, for the disk capacity in excess of 2 GB, one inode is allocated for every 8 KB of disk capacity up to a maximum of 2,097,128 inodes.
If the number of 1 KB file system blocks is represented by B and the number of inodes is represented by I, the inode allocation algorithms are as follows.
For disks with capacity less than or equal to 64 MB (65,536 KB):
I = B
For disks with capacity greater than 64 MB up to 2 GB:
I = 65536 + ( (B - 65536 ) / 4)
I has a maximum value of 524,264.
For disks with capacity greater than 2 GB up to 16 GB:
I = 524264 + ((B - 2097152) / 8)
I has a maximum value of 2,097,128.
Beyond this capacity, the maximum number of inodes remains constant at 2,097,128. Table 9-1 shows the number of inodes for various file system sizes. File systems cannot be larger than 16 GB and individual files cannot be larger than 2 GB.
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||
|
|
Inodes |
64 |
65536 |
65536 |
120 |
122880 |
79872 |
320 |
327680 |
131072 |
660 |
675840 |
218112 |
1000 |
102400 |
305152 |
2000 |
2048000 |
524264 |
4000 |
4096000 |
774120 |
8000 |
8192000 |
1286120 |
16000 |
16384000 |
2097128 |
Note: It is possible to run out of inodes before running out of file system space if all files are of a minimum size (say 1 KB).
Using Multiple Fixed Disk Controllers
Banyan server software supports multiple fixed disk controllers. At VINES 7.00, the server software no longer imposes a set of controller-ordering rules. (Controller-ordering rules allowed the system to be configured so the boot controller was found first by the VINES controller search order.) VINES 7.00 uses the system BIOS to find the boot controller.
Each fixed disk controller driver is one of two types:
Layered drivers - Layered drivers interface with a driver-to-kernel layer supplied by VINES. This allows third-party driver developers to supply only their hardware abstraction layer (the interface to the hardware); VINES supplies the peripheral device layer and the kernel-specific layer.
Monolithic drivers - Monolithic drivers supply all the software from the kernel layer to the hardware layer, including all peripheral device specific layers, such as for tape or CD-ROM.
You install third-party drivers using the Kernel Configuration Utility. All VINES-supplied drivers are layered drivers and are in the kernel. If you install monolithic, third-party disk drivers in the system, the Kernel Configuration Utility prompts you for a particular monolithic driver or for any one of the layered drivers to control the boot adapter. The layered drivers are treated as one because VINES has control of these and can automatically select the correct driver for the boot controller.
Note: No third-party, monolithic disk drivers are presently available.
Example Three Controllers with VINES 6.x and VINES 7.00
Assume a system has an embedded PCI-SCSI controller and two EISA-SCSI controllers. All three controllers have at least one disk attached. In VINES 6.x, the boot controller would have to be the EISA-SCSI controller in the lower slot number.
Note: Some VINES 6.x drivers include the necessary support to allow any of the three controllers control the boot disk.
In VINES 7.00, any of the three controllers can control the boot disk. If the BIOS is disabled on both EISA-SCSI controllers, the PCI controller controls the boot disk. If the BIOS on the first EISA-SCSI controller is disabled and the BIOS on the second is enabled, the second EISA-SCSI controller controls the boot disk.
This arrangement allows administrators to configure their systems the way they want.
Installing Additional Fixed Disks
The Banyan server software must be installed on logical disk 1 and not on an additional logical disk. Additional disks can contain Banyan services and the data areas used by those services.
For your server to access an additional disk, the disk must have a valid Banyan file system. When you install an additional disk on your server, a new file system is built on the disk. Since building the new file system destroys all data on the disk, make a copy of any data on the disk that you want to save.
To Install an Additional Fixed Disk
1. If the additional disk is not already low-level formatted, format the disk using the format utility supplied by the system or controller manufacturer.
2. Install the disk in the server.
3. Boot the server and watch for this message:
Disk /dev/rdsk/Xs0 contains an inappropriate VINES file system.
Consult documentation for proper disk installation procedures.
=====================================================
NOTICE: Logical disk N needs to be added.
=====================================================Use CTRL-S to stop the display and make note of the N. The logical disk number of the new disk is equal to N.
Use CTRL-Q to restart the display.
4. At the Operator Menu, select Shut Down Server Software. The system prompts you to confirm the shut down of all services.
5. Enter Y. The Shut Down Menu appears.
6. Select Shut Down Services and return console to OPERATOR MENU.
7. The following message appears:
Shutting down all services...
Do you wish to notify network users?- Enter Y to notify users of the imminent shutdown.
- Enter N if you do not want to notify users of the shutdown.
Once the shutdown is complete, the Operator Menu appears.
8. Select System Maintenance. The System Maintenance menu appears.
9. Select Configure/Diagnose Server. The Server Configuration menu appears.
10. Select Install/Repair Fixed Logical Disk Drive. The system prompts you for the drive number (2-12) you want to install.
11. Enter the logical disk number and press ENTER. The system prompts you to perform a surface analysis of the new fixed disk:
- Enter Y if you are installing a WD1003 fixed disk (ST506, ESDI, or IDE) or you question the integrity of the new disk. The system scans the disk to find defective blocks. An informational screen appears.
- Enter N if you are installing a SCSI or RAID fixed disk subsystem. Go to step 19.
12. Press ENTER to continue. The system reports the number of bad blocks and displays the following prompt:
Do you wish to enter any defect information by byte offset (y/n)?
- Enter Y to enter bad blocks by cylinder/head/byte offset. Go to step 14. If you choose this format, the system may prompt you for the fixed disk interleave factor.
- Enter N to enter bad blocks by sector number. Go to step 13.
13. This prompt appears:
Do you wish to enter any defect information by sector number (y/n)?
- Enter Y to enter bad blocks by sector number. Go to step 14.
- Enter N to skip entering bad blocks. To continue installing the disk, go to step 19.
14. Depending on the format you chose, the system prompts you to enter the appropriate defect information for each of the following:
- Cylinder number
- Head number
- Byte offset from index or sector number
15. Enter the appropriate information.
16. The system prompts you to confirm that each bad block you enter is correct.
- Enter Y if the information is correct.
- Enter N if the information is incorrect. Repeat step 14.
17. When you have finished entering bad blocks, press ENTER at the prompt for a cylinder number. Respond appropriately to any additional prompts.
18. The system prompts that the surface analysis is complete. When ready to continue, press ENTER.
19. The server constructs a new file system on the additional disk. The new file system is the size of the disk but you can change the size and create other file systems at the prompt:
Logical disk 2 has a total capacity of 1300 MB.
The following file systems will be created on logical disk 2:
File System Size
first 1300MB
Do you wish to override these defaults and specify your file system sizes? (y/n):Enter Y to specify file system sizes for the first and subsequent file systems.
After the file system is built, the Server Configuration menu appears.
20. Return to the System Maintenance menu and then return to the Operator Menu. Restart the server software.