SUMMARY: 2.6 initial install or upgrade from 2.5.1

From: Brown, Melissa (
Date: Tue Nov 30 1999 - 16:08:22 CST

I had nine responses. Most supported the initial upgrade whenever possible.
There were some really great comments for some gotchas to look out for, if
any, if you do the upgrade. It's definately worth reading if you're trying
to decide which route to take.
One of cons of the upgrade that I listed, "New versions of patches, mixed
with older patches can cause the system to become unstable" should be
modified. Apparently, the patches are updated, but references to old
patches that are no longer existent, remain.
My original posting, followed by the responses:
>Experienced Gurus :-)
>Does anyone have any written pros and cons about the subject of 2.6
>install or upgrade?
>I always prefer an initial install when the time is available and that's

>what I've been doing, but a colleague of mine wants to do an upgrade.
>So, has anyone done the upgrade and wished they hadn't?
>This is what I have so far for NOT doing the upgrade... and I know some
>these would be issues on an initial as well..... Of course, feel free to

>correct me on any of these!!
>>Upgrades from 2.5.1 to 2.6 do not upgrade all the libraries, especially
>>ones the compiler references, so the kernel might not be able to
>>2.6 takes more space than the 2.5.1 OS and requires larger partitions.
>>Some third party software or device drivers won't be compatible.
>>Old configuration files that are not compatible with the new 2.6 OS.
>>New versions of patches, mixed with older patches can cause the system
>>become unstable
 Thank you to Mark Langston, Dave Foster, Tom Jones, John McIntire, David
 gcarr, Dave Horsfall, Graham Shedd, and Marina Daniels
Well, I just went through a batch of these at work, since I didn't have
the luxury of time. Some "gotchas" I had to deal with included:
1) The presence of non-root-fs disks physically and in /etc/vfstab can
really confuse the auto-resize option in the upgrade, up to and including
the inability to upgrade the machine. Ended up turning off/detaching
the external drives, commenting out the mounts from /etc/vfstab. This
allowed the upgrade to proceed.
2) The total loss of an install after an upgrade, because the system
backed up the disks, resized the partitions -- wiping them -- and
then error'd out, complaining it was unable to recover the backed up
data. Seems the auto-resize didn't do its calculations properly.
(ended up having to clean-install that box).
3) The loss of swap file mount info from /etc/vfstab. Had to re-add
these manually.
#1 and 3 made me make a backup copy of /etc/vfstab before doing an upgrade.
4) On one system (the print server), the lp packages didn't install
properly. Ended up having to pkgrm and pkgadd them manually from the
5) Total loss of the Solstice Backup config info and indexes. Ether I
didn't see any warning about this anywhere, or it just wasn't documented.
Ended up having to do a catostrophic restore. Fun and time-consuming.
Unmount your real /nsr partition, or move the entire tree elsewhere
before upgrading.
6) Make *very* sure you've got the very latest patches. Discovered a
nasty CDE bug that causes the session to die unexpectedly. Patch for
this is not in the two-week-old 2.6_Recommended cluster I had. Ended
up running patchdiag and hand-scripting a mass-retrieval program to
get the latest patches from sunsolve, using ncftpget.
7) Run SunScan against the install to make sure you're Y2K-compliant.
8) Japanese Solaris: Looks as though they renumbered the /etc/rc2.d
scripts for Wnn6 between 2.5.x and 2.6, leaving you with two copies
trying to execute.
...and then there's the killing and moving of the powerd, nscd, snmpdx,
and dmi scripts, and turning on priority_paging in the kernel, as well as
tweaking maxpgio. But those are system- and use-specific, of course, and
not specific to an upgrade vs. initial install. Just 2.6-centric. :)

Mark C. Langston  < "> <> >
I upgraded 4 machines from Solaris 2.5 to 2.6, with no problems related to
actual upgrade process itself. We had some hardware and software that didn't
particularly like 2.6, but that's another issue. I've found the newer
of Solaris to have very clean installation tools, and have never had
with doing the upgrades. Save a lot of re-configuration!
OTOH, if you have the time, a fresh install is always better.
David Foster < <>  >
We have around 19 Sun boxes that were upgraded from 2.5.1 to 2.6 with the
only problem experienced was with CiscoSecure. (upgrading CiscoSecure solved
Tom Jones < <> >
I got bit when I upgraded to 2.6 from 2.5 with the /usr partition growing by
200 MB
John McIntire  < <> >
The 2.6 upgrade does not update all the manual pages and does not 
remove the references to 2.5.1 patches. The patches are non-existent 
but the references to them are still there. 
The compiler references will be updated if you reinstall the compiler. 
I have done many 2.5.1 -> 2.6 upgrades with no problems but for 
philosophical reasons I prefer a fresh install where possible. 
David Evans  < <> >
We did an upgrade from 2.5.1 to 2.6 on about a dozen machines and didn't
see any significant problems except for the larger partitions. Found it
difficult to get 2.6 into a 1 Gbyte disk with our standard configuration.
< <> >
I've always upgraded instead of installed - no problems. And watching
it re-partition the root disk on the fly is a real buzz :-)
Dave Horsfall VK2KFU 
I have done both the initial install and the upgrade and I prefer the
initial install.
With the upgrade apart from the comments you had in your email regarding
libraries you also have to consider disk space. If you don't have enough on
your internal hard disk then you can copy files off to another system and
then bring back. The upgrade utility does this for you, but you have to
consider things lke .rhosts or hosts.equiv files when planning the upgrade.
I always try to do a new install, especially if you are going from Solaris
2.2 to 2.6. You can patch from 2.2 to 2.3, to 2.4 to 2.6 but it is a real
pain. Far better to go for the straight forward initial install.
That's my two pence worth anyway
regards Graham < <> >
That last line doesn't make sense. When you do an upgrade it removes 
all the old operating system patches and then you install the latest 
recommended set and it is fine.
Marina < <>

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