Preparing for I/O System Changes

This section describes tasks you may need to do to prepare your system for the I/O-subsystem changes that were introduced at 10.0.

Before You Start

You should already have read the section on "I/O Convergence" in the Release Notes for HP-UX 10.10. If you haven't, read it now. (See “Locating and Loading Tools and Documentation”, earlier in this chapter, for instructions for getting this document from tape or CDROM.)

You may also need the 9.0 versions of the Series 700 and 800 HP-UX System Administration Tasks manuals.

You should also make sure you have copies of the 10.0/10.01 versions of the following books:

Configuring HP-UX for Peripherals
HP-UX System Administration Tasks

If you have developed in-house drivers for any of your Series 700 systems, you also need the Driver Development Guide.

Summary of Tasks

As you can see from the Release Notes for HP-UX 10.10, most of the work for I/O convergence will be done for you during the upgrade itself. This section summarizes what preparation (or, in some cases, follow-up, after loading 10.01) you need to do, if any. Instructions are in the sections that follow; use this section as a checklist.

For disks:
- If you are running DataPair/800, order and migrate to MirrorDisk/UX (Series 800).
- Convert Series 800 disks from hard partitions (Series 800) to Logical Volume Manager (LVM), if you so decide.
For drivers:
- Make sure that drivers for key applications will be available before you upgrade to 10.01.
- If you use an optical autochanger, modify scripts and procedures to take account of the 10.01 driver change that allows you to mount only as many filesystems in the autochanger as the autochanger has drives.
For device files:
- Check code and scripts for use of mknod to create device files.
- Check for symbolic links.

The sections that follow provide instructions for these tasks, or tell you where to find instructions.

Disks

You should already have read the section on "Disk Configurations in 9.x and 10.x" under "I/O Convergence" in the Release Notes for HP-UX 10.10. That section outlines the disk-management choices available to you as you upgrade from 9.x to 10.01; if you didn't read it or don't recall it, spend a few minutes reviewing it before you go on.

You have work to do before the upgrade to 10.01 if:

You are using unsupported disks; or
You are using DataPair/800 for disk mirroring (Series 800); or

You want to convert hard-partitioned disks to Logical Volume Manager before you upgrade to 10.01 (Series 800).




	NOTE: If you want to convert disks on a Series 800 system to Logical Volume Manager (LVM), you can do so before or after upgrading the system to 10.01 or 10.10. If you want to convert disks on a Series 700 system to Logical Volume Manager (LVM), you must first upgrade the system and boot it on 10.01. 9.07 systems must be upgraded all the way to 10.10 before you can convert disks. On other Series 700 systems, you can convert disks on 10.01, 10.10, or later. You cannot convert disks to LVM during the upgrade. Instructions for converting disks to LVM on a 10.01 or 10.10 system (Series 700 or 800) are in chapter 3 of the 10.01 version of the HP-UX System Administration Tasks manual, under "Converting Current Disks to New LVM Disks".

If You Are Using Unsupported Disks

If the disks you are using came packaged with the system, or you bought them from HP to use with this system, they are supported; you need not read any more of this subsection.

If you have substituted or added a disk that you did not buy from HP:

If this is the root disk (the disk containing the / directory):
- The upgrade could fail, even if the disk has been working on 9.x.
Call HP to confirm that this disk is supported for 10.01.
If this is not the root disk:
- Run ioscan.
  If ioscan shows that the disk is CLAIMED, the disk will upgrade successfully and will be accessible on 10.01.
  If ioscan does not show the disk as CLAIMED, the disk will not upgrade successfully and will not be accessible on 10.01.
  (But you could still upgrade the rest of the system if decided to go ahead; an unrecognized non-root disk will not in itself cause the system upgrade to fail).

If You Are Running DataPair/800 (Series 800)

DataPair/800 is not supported as of 10.0. If you want to continue to use mirrored disks in 10.x, you need to:

Order MirrorDisk/UX from HP (optional product supported on 9.0 and later).
Migrate the disks to mirrored logical volumes, using LVM and MirrorDisk/UX.

The Series 800 HP-UX System Administration Tasks manual for 9.0 (HP part number B3108-90005) contains instructions for migrating disks mirrored via DataPair/800 to LVM and MirrorDisk/UX. See the section "Migrating Data From DataPair/800 to LVM's MirrorDisk/UX" in chapter 8 of that manual, "Managing Logical Volumes"; the procedure begins on page 8-139.

If You Want to Convert Hard-Partitioned Disks to LVM (Series 800)

10.x does not require LVM; existing hard-partitioned disks will continue to be supported.

But you may want to convert your disks to LVM — for example, if you are currently using DataPair/800 and want to continue using disk mirroring under 10.01, you will need to convert the disks in question to LVM and migrate to MirrorDisk/UX (see the previous section).

If you decide to convert some or all of your disks to LVM now (while running 9.x), follow the directions below.

There are three kinds of conversion you may want to do:

Convert hard-partitioned, non-root disks to LVM.
Move the root filesystem from a hard partition to a new disk to be managed via LVM.
Convert the current root disk to LVM.

1. To convert hard-partitioned non-root disks

Instructions for this are in the 9.0 version of the Series 800 System Administration Tasks manual, in chapter 8, "Managing Logical Volumes." The procedure begins on page 8-134.

2. To move the root filesystem from a hard partition to a new disk to be managed via LVM

Instructions for this are in the 9.0 version of the Series 800 System Administration Tasks manual, in chapter 8, "Managing Logical Volumes." The procedure begins on page 8-121.

3. To convert the current root disk to LVM

You need to back up the root disk, run the lvmmigrate tool, re-install the current version of HP-UX (for example 9.0), and recover the backup.

The following is a cookbook for doing this.




	NOTE: If you want a more detailed procedure, you'll find one in the Series 800 version of Installing and Updating HP-UX 9.0, in chapters 3, 4, 5 and 8; but note that you do not need to perform the steps in those chapters that deal with saving off and restoring custom files (you will simply back them up and recover them along with everything else) or loading the `lvmmigrate` tool (it is part of HP-UX 9.0, which is already on your system).

Perform the following steps.

Bring the system to single-user mode.
Do a full backup of the root disk.
(For backup procedures using various tools, see chapter 9, "Backing Up and Restoring Your Data", in the 9.0 version of the Series 800 System Administration Tasks manual.)
Run lvmmigrate(1M):
/etc/lvmmigrate -v | more
lvmmigrate saves its output in /tmp/LVMMIGRATE. Print out this file.
For a guide to using this file to prepare for re-installation, see the Series 800 version of Installing and Updating HP-UX 9.0, near the end of chapter 3. See also the lvmmigrate(1M) manpage.

Re-install the current version of HP-UX (for example 9.0).

Shut down your system and turn off the computer.
Load the install tape or disk.
Boot the computer, interrupting the boot sequence so as to interact with the Initial System Loader (ISL).
Proceed with the installation, following prompts to install with LVM.

For detailed instructions, see chapters 4, 5, and 8 of Installing and Updating HP-UX 9.0.




	NOTE: You do not need to take the special steps indicated in chapter 8 of Installing and Updating HP-UX 9.0 to recreate system files; simply recover them from your backup along with everything else when the migration is complete.

Migrate any filesystems, other than root (/) and /usr, that were on your root disk.
Use the /tmp/LVMMIGRATE file to identify the filesystems if you need to. Use SAM to create the necessary logical volumes and add back the filesystems.
See the section "Migrate Non-Root File Systems on Root Disk" in chapter 8 of Installing and Updating HP-UX 9.0 if you need detailed instructions.
Recover your backup.
Return the system to multi-user mode to let your users back on.

Other Considerations for Series 800s

At 10.0, the definitions of sections 2 and 0 on hard-partitioned disks were switched, so that section 0 specifies "whole-disk" access and section 2 specifies the section of the disk that used to be section 0.

There is nothing specific you need to do to prepare for this: no data will be moved or overwritten.

Symbolic links will ensure that you continue to access the disk in the same way as you did before the upgrade. If you were accessing the whole disk via section 2 at 9.x, you will continue to read and write to the whole disk on 10.x. Disk access to 9.x section 0 will be redirected to the same physical location via 10.01 section 2.




	NOTE: If you keep diagrams mapping sections of your disks to their contents, you may want to switch the zeroes and two's before upgrading to 10.01. Most device-file names and major and minor numbers, including those for disk sections, are changing in 10.01, but you will still be able to address the correct section by the old name, because the old name will be symbolically linked to the new file. Once you are on 10.01, do not use `mknod(1M)` to create device files for disk sections. Avoid `mknod` in general; it requires you to know major and minor numbers and to supply a device file name; since these are all changing in 10.01, you should use `mksf(1M)` and `insf(1M)` instead; they will do the right thing.

Considerations for Series 700s

For Series 700 machines, there are no disk-management tasks to do before you upgrade to 10.01. But keep the following points in mind:

If your system includes SDS disk arrays:
- During the upgrade to 10.01, the upgrade software will convert these arrays to striped logical volumes.
  The conversion is done for you; you do not need to intervene to make it happen.
  The following restrictions apply to the LVM configuration that the upgrade program creates:
  The volume group created for each SDS array can support a maximum of eight disks.
  You can add disks to the volume group if the SDS array contained fewer than eight disks, but the group can never contain more than eight.
  NOTE: The manpage says a volume group can contain up to 16 physical volumes; but the volume group created by the SDS conversion is an exception.
  This restriction does not apply if you create a new volume group.
  The volume group created for each SDS array can contain a maximum of eight logical volumes.
  NOTE: The manpage says a volume group contain up to 255 logical volumes; but the volume group created by the SDS conversion is an exception.
  HP does not at present support mirroring of data on LVM disks that have been migrated from SDS.
  LVM disks migrated from SDS do not support bad block relocation.

If your system includes single SDS striped disks:

10.x will continue to support these SDS disks via a "compatibility driver" (cpd).

During the upgrade, the disk label is rewritten so that these disks can be managed by the cpd.




	NOTE: As a result, these are no longer true SDS disks; they are more like Series 800 hard-partitioned disks. If the disk crashes, or the label is removed or damaged, you cannot recreate the label, nor replace the disk with another SDS disk. In that case, the only way to continue to manage the disk's data in "stripes" is to reformat the disk, or its replacement, as an LVM striped disk. See the section on "Troubleshooting an Existing SDS Disk" in chapter 3 of the 10.01 version of the HP-UX System Administration Tasks manual.

If you prefer to manage these disks under LVM, you can convert them to striped logical volumes after upgrading to 10.01. See “Converting Disks to LVM (Series 700) ” for more information.

If there are any SDS disks on the system, the LVM-RUN fileset will be installed automatically during the upgrade (so long as you choose Match What Target Has and DO NOT "unmark" the LVM-RUN fileset). You can remove the fileset after the upgrade if your 9.x system did not have any SDS arrays; see “Removing LVM ”.




	CAUTION: Device files for all SDS disks must be in the path `/dev/dsk/` and they must be named according to the HP-UX 9.x naming convention for Series 700 disks. See the next subsection, “Device File Convention Supported for SDS conversion ”, for details. The 9.x-to-10.01 upgrade is the only way to convert SDS disks automatically. On a 10.x system: An SDS array that has not been converted during the upgrade will not be usable. SDS disks will not be converted during the upgrade if: They are attached to a cluster client that was not booted to the cluster during the upgrade to 10.01. They are not configured into the system to which they are attached before you run the upgrade to 10.01. They are not physically attached to the system and online during the upgrade. You do not load LVM during the upgrade to 10.01. `Match What Target Has` selects LVM for you; make sure you choose `Match What Target Has` and DO NOT `unmark` LVM. If you discover that you have accidentally failed to make an SDS array available for conversion, your only remedy is to attach it to another 9.x system, import it into that system (using `sdsadmin` with the `-i` option), then upgrade that system to 10.01. An SDS single disk can be converted to LVM (whether or not it has been converted for the `cpd` during the upgrade); but you must back up the data and re-initialize the disk for LVM. See “Converting Disks to LVM (Series 700) ”.

If your system includes disks being managed as "whole disks" (the default until now):
- You can continue on 10.01 with no change from 9.x; or
- You can convert some or all of your disks to LVM after upgrading to 10.01.
See “Converting Disks to LVM (Series 700) ” for more information.




	NOTE: Root disk special cases: The only way to convert a Series 700 root disk to LVM is to upgrade to 10.x, then re-install 10.x with LVM; conversion during the upgrade is not possible. 9.07 systems must be upgraded all the way to 10.10 before you can re-install with LVM. Never try to re-install (or install) 10.01 on a 9.07 system. On other Series systems, you can re-install with LVM any time after upgrading to 10.01. If your root disk is currently configured for SDS, you have an unsupported configuration. Back up your system and re-install the 9.x release you are currently on before attempting to upgrade to 10.01.

Device File Convention Supported for SDS conversion

The SDS conversion software (which is part of the 9.x-to-10.01 upgrade software) recognizes only device files whose names have the same format as those created during system installation time.

Device files whose names do not follow this convention will not be recognized, even if they were created by HP utilities such as SAM.

The following are examples of device files (in /dev/dsk) that will be recognized by the conversion software.

Type of Card     Device-File Name          Example
-
 
Single-ended     c<XXX>d<disk_addr>s0      c201d0s0
SCSI             where <XXX> is the        (for built-in
                 high 3 nibbles of         SE-SCSI with
                 the minor number,         disk_addr 0)
                 in hexadecimal
 
EISA             c4[1234]d<disk_addr>s0    c43d0s0
                                           (for EISA card
                                           in slot 3 with
                                           disk_addr 0)
 
Fast/Wide SCSI:                            (for Fast/Wide
                                           SCSI in slot 1)
9.05             c[ABCDEF]0ds0[ABCDEF]s0   cA0dB0s0
9.07             c[abcdef]0d[abcdef]s0     ca0dbs0




	NOTE: For Fast/Wide SCSI, if `disk_addr` is greater than 9, the disk address will be represented in hexadecimal upper case for 9.05 and in hexadecimal lower case for 9.07.

If you have SDS device files that do not meet these criteria, snoop will warn you that you need to create new ones. You must do this before you upgrade.

The following is an example of a warning message from snoop for a single-ended SCSI disk which has "201" as the minor number:

NOTE:    Found SDS disk /dev/dsk/c201d0s0
PROBLEM: upgrade has detected a SDS disk on your system.
         but the corresponding device file
         /dev/dsk/c201d0s0 does not exist. Please create
         the device files (both block and raw) for this disk.
         example:
         mknod /dev/dsk/c201d0s0 b <dev major number> 0x201000
NOTE:    Found SDS disk /dev/dsk/c201d1s0

Drivers

When you upgrade to 10.01, the following things will happen:

The upgrade software will remove all 9.x drivers from the kernel.
Drivers bundled with the 10.01 software being loaded onto your system will be bound into the new 10.01 kernel.

This means that the following classes of driver will not be bound into the kernel from which the new 10.01 system boots:

Custom drivers written by your in-house programmers.
Drivers written by third-party (non-HP) vendors.
HP drivers that are not bundled with 10.01 (or that are bundled with 10.01 products that you haven't loaded).

What You Need to Do

For in-house drivers (if any):
- Warn programmers responsible for any in-house drivers that they should begin revising their code to comply with 10.x.
  The Release Notes for HP-UX 10.10 provide a summary of the changes needed; for details, programmers writing for the Series 700 will need the 10.0 Driver Development Guide. HP is not publishing any guidelines for writing Series 800 drivers for 10.x.
For third-party (non-HP) drivers:
- Check with the vendors to find out when 10.x-compliant drivers will be available.
For HP-supplied drivers that do not come bundled with HP-UX:
- Check with your HP Service Engineer (SE) to find out when 10.x-compliant versions of these drivers (or the applications to which they belong) will be available.
- For the autochanger:
  Modify scripts and procedures, if necessary, to take account of a restriction in the 10.x driver, ssfrc, that allows you to mount only as many filesystems in the autochanger as the autochanger has drives.
  See “Autochanger Driver Changers ”, later in this section.

Are all 9.x drivers incompatible with 10.x? Not necessarily; in fact most drivers written according to guidelines in the 9.0 version of the Driver Development Guide should continue to work on 10.x. But HP cannot guarantee that they will work, which is why they will not be bound into the kernel built by the upgrade software, the kernel from which your 10.01 system will initially boot.

After booting 10.01 or 10.10, you can try rebuilding the kernel so as to include 9.x drivers that have been removed and not replaced during the upgrade (see “Adding Drivers ”).

But, for drivers that critical applications depend on, it is not a good idea to wait and see. Contact the supplier, find out when a 10.x-compliant version of the driver (or the application it is part of) will be ready, and wait until that time to upgrade.

Autochanger Driver Changers

Autochanger driver behavior has changed as of 10.0. On 10.x systems:

You can mount only as many platters as there are actual autochanger drives.
HP-UX creates only as many device files as are needed to communicate with those drives.
Hard-partitioning on autochanger surfaces is no longer supported,
The device-file naming convention has changed.
9.x autochanger device files will be removed during the upgrade to 10.01, and only those that relate to actual drives will be replaced (see “Device Files ” later in this chapter).

For more information, see the manual Installing and Administering Optical Jukeboxes on HP 9000 Series 700 and 800 Systems; the driver changes are described in an appendix, "HP-UX 10.0 Autochanger Driver Changes and Developer's Guide".




	NOTE: Order Installing and Administering Optical Jukeboxes on HP 9000 Series 700 and 800 Systems using the HP part number 5960-7624 Edition 3. The manual title and part number given in earlier versions of Release Notes (before 10.10) are incorrect.

You'll find a brief summary of the most important change, the restriction on virtual mounts, in the "I/O Convergence" section of the Release Notes for HP-UX 10.10, under the heading "Autochanger Virtual Mounting".

The restriction on mounts may affect scripts. For example, in 10.x, mediainit, newfs and mount open a device with the O_NODELAY (non-blocking) flag set. If the ssfrc driver receives such a request when all the drives are busy, it will fail with EBUSY.

The following script, for an autochanger containing two drives, presents no problems on 9.x, but needs to be modified for 10.x:

#!/bin/ksh
# mi.ksh:  9.0x script to mediainit the first six
# cartridges in the autochanger
#
mediainit /dev/rac/1a &
mediainit /dev/rac/1b &
mediainit /dev/rac/2a &
mediainit /dev/rac/2b &
mediainit /dev/rac/3a &
mediainit /dev/rac/3b &
mediainit /dev/rac/4a &
mediainit /dev/rac/4b &
mediainit /dev/rac/5a &
mediainit /dev/rac/5b &
mediainit /dev/rac/6a &
mediainit /dev/rac/6b &
wait

This script should be modified as follows for 10.x:

#!/usr/bin/ksh
# mi.ksh:  10.x script to mediainit the first six
#cartridges in the autochanger.
#The 'waits' are necessary because mediainit in 10.x
#performs opens with O_NDELAY.
#
mediainit /dev/rac/c1t3d0_1a &
mediainit /dev/rac/c1t3d0_1b &
wait
mediainit /dev/rac/c1t3d0_2a &
mediainit /dev/rac/c1t3d0_2b &
wait
mediainit /dev/rac/c1t3d0_3a &
mediainit /dev/rac/c1t3d0_3b &
wait
mediainit /dev/rac/c1t3d0_4a &
mediainit /dev/rac/c1t3d0_4b &
wait
mediainit /dev/rac/c1t3d0_5a &
mediainit /dev/rac/c1t3d0_5b &
wait
mediainit /dev/rac/c1t3d0_6a &
mediainit /dev/rac/c1t3d0_6b &
wait

If the script were left unmodified from the 9.x version, the last ten mediainits would fail with EBUSY, because no drives would be available.

For more information, see the appendix "HP-UX 10.0 Autochanger Driver Changes and Developer's Guide" in the manual Installing and Administering Optical Jukeboxes on HP 9000 Series 700 and 800 Systems, HP Part Number 5960-7624 Edition 3.

Device Files

Most of the device files on your 9.x system will be removed and replaced during the upgrade to 10.0. This is to accommodate a new naming convention and a new major and minor numbering scheme that support I/O convergence, that is, a single convention for both the Series 700 and 800.

You do not have to do a great deal to prepare for this change; although old device files will be removed, their names will be preserved as symbolic links to the new files. This means that code and scripts that invoke the old names will continue to work on 10.x.

But you do need to check for three things:

Use of mknod(1M or 2), in code, scripts, or written procedures to create device files. Use mksf or insf instead of mknod on 10.x.
Use the prepare(update_aid) tool to check for calls to mknod; see Chapter 5 “Converting Code and Scripts ” for details.
Symbolic links to 9.x device files.
Make a note of any such links that may exist on your current system. You will need to rebuild them after upgrading.
Autochanger device files that do not relate to actual drives.
The upgrade process will remove all the 9.x autochanger device files, and replace them with only as many new device files as the autochanger has drives.
The old names that related to actual drives will be retained on 10.x as links to the new files; but names of device files that have no corresponding drive will not.