HP-UX 11.0 Patching dependencies question

[Lane Frazier]

Hello all,

I just recently went through a rather strange issue applying a patch on HP-UX. The issue concerns patch dependencies.

Here's my sceanrio:
I install the latest Ignite-UX....later read that I really should install the latest pax patch....PHCO_20416.

I go to read about the patch and its says in the dependencies section PHKL_19991 which I don't have on my system. Further more the patch database gives the indication that PHCO_20416 needs about 10 addn'l patches which I don't have on.

I'm running May 1999 level so I take a deep breathe and consider putting on the June 2000 update...just for grins I call HP to talk it over with them.

They tell me....that since I have an older pax patch on that the new one will go one without the the need for the June 2000 update or PHKL_19991 for that matter?! Huh?..

I grit my teeth and put on PHCO_20416...nary a problem..While I'm grateful for only needing to apply this one patch instead of many I am now totally confused about prerequisite or dependency patches! I'm an old mainframe guy and when something is dependent...it means you can't do it till the dependency is met!

I've read the doc on patch mgt and do not recall this really being discussed...Can someone explain to me what is going on here.

Thanks again

[Rick Garland]

You need to be careful about patch depends and loading them. If you check out a patch and it says it depends on another patch, get both of them. Put into a depot and you can install through one swinstall session. Be aware that there are superceded patches, patches that have a depend which depends on another patch, etc... End result is you may need multiple patches to install a patch that is what you wanted to begin with.

Need to follow the loops as to getting and installing patches. If you have a depot, put all the patches in there and this will allievate the need to be aware of the depends. You can install all your marked patches in the same swinstall session. If the patches require reboot. only one reboot.

Some patches that have depends can be troublesome if you do not load the depends.

[James R. Ferguson]

Lane:

I chased through this too. I believe the issue is simply to make sure that you have a version of pax that handles sparse files. The current level of patch available is far beyond the level that actually fixed the problem. If you drill down into the patch text notes I think you will find that you meet the requirements.

...JRF...

[Lane Frazier]

I agree about being careful...so how is it that that I got the patch installed without the dependency being on?....luck or is it because I already had an older pax patch on..

Unfortunately, the dependcency patch has dependents as well...it gets to be a mess in a hurry...still don't understand how I got PHCO_20416 on without PHKL_19991..

How does one explain the discrepency between the dependencies in the patch description and what you get from the patch database shopping cart screen. They are vastly different.

[John Palmer]

Well...

PHKL_19991 has been superceded by PHKL_22022, have you got that one installed?

[Rick Garland]

Some of the dependiencies are for the specific utilities that you are patching. These will not necessilarily cause a system to go wierd but could make the utility do things it is not suppose to.

The descrepency in the patch description and the shopping cart can be because the shopping cart is not necessarily being updated with superceded patches. It can be mind-numbing (to say the least) when you have to go into each patch and check the text for depends, special instructions, etc. I remember once that it was that 1 patch was recommended, after I got done checking, I actually needed 7 patches.

[Lane Frazier]

Hello again...No I do not have PHKL_22022 on either.

What worries me about all this is that swinstall put the patch on without the dependencies being met....I thought it would not do that....scary to think about

[Mark Mitchell]

I just did this last weekend. Loading Ignite is quick and doesn't require a reboot. I didn't have many of those patches either and I didn't install them. The patches are for fixing problems with VXFS file systems, I use hfs so I skipped the whole bundel and haven't had a single issue.
If you do have VXFS file systems, take this list of patches and check them on your system
PHKL_20016 2nd CPU not recognized in G70/H70/I70
PHCO_20416 pax(1) cumulative patch
PHKL_20674 fix VxFS unmount hang & MMF, sync panics
PHCO_20882 fsck_vxfs(1M) cumulative patch
PHCO_21187 cumulative SAM/ObAM patch
PHKL_21392 VxFS performance, hang, icache DPFs
PHKL_21532 boot,JFS,IOperf,PA8600,3Gdata,NFS,IDS,PM,VM
PHKL_22022 rcp sparse file fix, mmap, IDS/9000 support
PHKL_19169 139 99/07/29 s700_800 11.00 Correct VxFS process hangs
PHKL_19991s700_800 11.00 Fixes mmap & I/O coherency, enables JFS ACL

these listed below are included in the ones above so don't worry about them
PHCO_13411 and 13377 to PHCO_20882 (up above)
PHCO_13387 now 18543 (already installed)
Now once you get them make a software depot, because 6 of them require a reboot. And make a good backup because 21187 is 19 megabytes and touches everything in site. When you see that most patches are about 500 kilobytes, you know what I mean.

[Thomas Schler_1 · Accepted solution]

The dependency section of a patch description tells you what patches should be on the system before installing or with installing the new patch.

The fact that you do not see patches on the system that are listed as dependent patches in the patch description does not mean that dependencies are necessarily not solved. Your system may have older patches that can be superseded by newer patches listed in the dependency section of your patch description.

This seems to be a little bit complex.

In your special case PHCO_20416 depends on PHKL_19991 which is not on your system, but you may have installed an older patch. Try to verify this with 'swlist | grep -i mmap'. "mmap" is part of the patch description which does not change with higher numbers of superseding patches. Compare the patch description of PHKL_19991 with that swlist gives you. If they are the same the dependency of PHCO_20416 is solved. If they are not the same you should think of installing PHKL_19991 (or its superseding patch: there's a new one: PHKL_22022).

If you choose to install PHKL_19991 (or its superseding patch PHKL_22022) you have to be sure that dependencies are solved for this new patch. Check this with the patch description. You can imagine that there is a chain of patch dependencies with each other patch and sometimes it is hard to follow the dependencies until you resolved them all. Don't do that.

Hold on and go back to the first step: Install or not install PHCO_20416?

You installed the May 1999 patch level which means that you have a patch bundle on your system with all dependencies solved (since this bundle is released by HP). Therefore, you were able to install PHCO_20416. If you used swinstall you should have used the option "Enforce dependency analysis errors in agent". This option is enabled by default. So, swinstall would tell you if it could not install the patch due to not resolved dependency.

Trying to summarize, the problem is twice: 1.
Each patch may be a superseding patch of another, or may be superseded by another. 2. The dependency list of the actual patch PHxx_11111 only lists patches that are the newest ones when PHxx_11111 was released.

For the future I recommend:

a) Install one or two patch bundles released by HP each year. Dependencies are resolved.
b) If you want to install one patch with dependencies check if your system has patches installed that are listed in the actual patch description text, or that are superseded by patches listed in the actual patch description text. If so, dependencies are resolved.
c) If you want to install one patch with all its dependencies using the newest patches give the order to HP support to send you a tape with the patch and all its dependencies.

[Tracey]

Did you check to see if you swinstall options still have the default "Check dependencies" option set on?

[Mark Mitchell]

As for patch management, I will have to offer this opinion. I don't believe in blasting a functional system with patch bundles. If you look at this page you see people who ended up restoring their server because of boot problems after the install. I would recommend using a patch when you have a problem and you can see that it resolves it. Like above, I don't have VXFS fs on the system so I am not going to load 20 megs of patches that can create more problems. If I have a parse problem then I will load the one, you have to think about it like surgery with a scalpel or a shotgun.
Take the time to create a tree diagram of the patch and dependancies after you know that you really need them.

[Lane Frazier]

This has gotten way more complex than it needs to be. I tend to subscribe to the school that if it aint broke don't fix it....( I usually don't have to look too far for broken stuff). That said I hate to get hung out to dry putting on individual patches...

I called HP again (not that I don't trust you folk) and pressed them on the dependency issue. Here's what I found.

the pax patch PHCO_20416 needs PHKL_19991 now superceeded by PHKL_22022....I have neither of these on....

BUT....Because I had PHKL_16983 on my system swinstall put PHCO_20416 on.

Autoselect depedencies is on in my swinstall options which is what enforces this I guess....I don't think I'll ever "understand" this....

Think I'll wait till December and put the June 2000 patches on......way too much sugar for a dime!

[marc seguin]

Be careful !
Patches which are necessary for other ones are not automatically selected, even with the "autoselect_dependencies=true" option. And the installation will go on without the dependencies, even if you use "enforce_dependencies=true" option (the default one).
The only exception I saw was with dependent patches of PHKL_18543, which can't be installed if you don't have PHKL_18543.
So don't expect swinstall to warn you about dependencies not installed. You have to read the text file and to look for dependencies by yourself.
And don't trust the guy who says (above) that an older version of a dependency should be enough. You can't know if the older version meets the requirements or if you really need the new version HP ask for.