[CentOS] upgrading 7.5 ==> 7.6

[Simon Matter]

> On Wed, Dec 19, 2018 at 01:50:06PM -0500, Fred Smith wrote:
>> hI ALL!
>>
>> There have been a large enough number of people posting here about
>> difficulties when upgrading from 7. to 7.6 that I'm being somewhat
>> paranoid about it.
>>
>> I have several machines to upgrade, but so far the only one I've dared
>> to work on (least critical if it goes bad) is my new-to-me-but-used
>> laptop.
>>
>> First I did a 'dd' backup of the whole drive onto an external USB drive
>> then did the upgrade. Since I use the Mate desktop, I enabled the
>> epel testing repo (per postings on Mate troubles at the time of the
>> upgrade).
>>
>> Result: Boots to GDM just fine, but Mate is a black screen. Switching
>> to Gnome, works fine, but I can't stand Gnome.  Not knowing what else
>> to try I restored the dd backup.
>>
>> Later I inserted a spare HD and did a new install from the DVD
>> media. This installed without issue, but now no desktop works.
>> Switching to a console (CTRL-ALT-F2) I did a full "yum update",
>> which installed quite a few packages, but upon reboot nothing had
>> improved. So I added the epel repo (and testing) and installed Mate.
>> Ditto, nothing had changed.
>>
>> This laptop is fairly old, and according to lshw, has a RV635/M86
>> [Mobility Radeon HD 3650]I] video chipset, in case it matters.
>> CPU is identified as: Intel(R) Core(TM)2 Duo CPU     T9400  @ 2.53GHz
>>
>> Having previously installed 7.5 on it without trouble, on which Mate
>> works just fine, I wonder what could have become so broken that neither
>> an upgrade nor a fresh install works.
>>
>> I have, as I said, several other machines to  upgrade, too, some of them
>> have Nvidia grahics (esp. my main desktop box, which also uses Linux
>> software RAID-1) and all run Mate. Then there is a netbook (low
>> priority)
>> a couple of VMs (in virtualbox) and at work several other VMS as well as
>> bare-metal on a Lenovo deskside machine, and I'm afraid to do an update
>> on all of them because I need them to be in usable condition. The Lenovo
>> box in my office is somewhat urgent, as I am about to retire and turn
>> it over to someone else who doesn't know much about Linux.
>>
>> I'd appreciate any advice I can get on how to get these systems upgraded
>> without breaking them.
>>
>> thanks in advance for your help!
>>
>> Fred
>
> One more data point: After taking a dd backup of the HD in my Acer
> Aspire One netbook (screaming 1.6 GHz Atom, dual core!!), I did the
> 7.5 to 7.6 update and it went perfectly fine, although it had 800
> packages to update, so it was kinda slow.
>
> Do any of you know if the various Nvidia issues, and problems upgrading
> software RAID1 systems have reached resolution? I haven't seen postings
> here regarding solutions for those problems, and knowing my luck, I would
> hit both of 'em on my personal desktop.

I didn't see any issues with RAID. I think those problems arise only if
you have old RAID devices created with older CentOS releases than 7. Those
were probably created with 0.9 metadata version which may be a problem.
Currently 1.2 metadata version is created and I didn't see any issues with
it.

Maybe others can confirm my conclution.

Regards,
Simon