On 05/10/2016 12:19 AM, Johnny Hughes wrote:> On 05/10/2016 02:08 AM, Venkateswara Rao Dokku wrote: >> Hi, >> >> I would like to know whether the valid upgrade path will be present from >> CentOS 7 to future versions like we get for Ubuntu or some other operating >> systems. >> >> Right now, I am sure that we do not have proper update path in CentOS to >> move from one version to another. >> > > If you mean upgrade to all CentOS-7 point releases, yes (from source > code for RHEL-7.0 to RHEL-7.1, to RHEL-7.2). If you mean from CentOS-7 > to CentOS-8, there is no way to know. There is no RHEL-8 to look at. > > Red Hat has source code for preupgrade-assistant and > redhat-upgrade-tool. That is created for inplace upgrades from one > major version to another. Currently those tools are community and > maintained and they are several updates behind because currently no one > in the community has stepped up to maintain them. > > But, CentOS-7 has an EOL of June 30, 2024 .. so there is security > updates for 8 more years. > >I tend to keep all server content in /srv and all user content in /home Upgrading from one major version to another then is pretty simple - but not on the same machine. I do a fresh install of the new version in a new vm, make sure all the services are in place, and all the user and group ids match. I can then rsync the old /home and /srv to the new system. Yes there are server migration files that need to be migrated but what I like about this approach is I can keep serving from the old server until this is done and tested in the new server, and then it is just a simple DNS change and the new server is used. Migrating configuration files to me means starting with the defaults in the new version and modifying them to match the needs of the service, not replacing them with the old files. I have tried updating between major versions in Fedora before and there were always too many glitches, it really is better to clean install and migrate the data. In my opinion. Especially if you skip a release like I tend to do.
m.roth at 5-cent.us
2016-May-10 20:29 UTC
[CentOS] Upgrade path from CentOS 7 to future versions
Alice Wonder wrote:> On 05/10/2016 12:19 AM, Johnny Hughes wrote: >> On 05/10/2016 02:08 AM, Venkateswara Rao Dokku wrote: >>> >>> I would like to know whether the valid upgrade path will be present >>> from CentOS 7 to future versions like we get for Ubuntu or some other >>> operating systems. >>> >>> Right now, I am sure that we do not have proper update path in CentOS >>> to move from one version to another. >> > I tend to keep all server content in /srv and all user content in /home > > Upgrading from one major version to another then is pretty simple - but > not on the same machine. > > I do a fresh install of the new version in a new vm, make sure all the > services are in place, and all the user and group ids match.<snip> I had an article published in the late, lamented SysAdmin magazine about 10 years ago, where I recommended having a three of spare partitions, doing an install using those for /, /usr and /boot - though now you could get away with / and /boot. Then, if you had show-stopper issues, you could always boot back via the old partitions. Where I work, I don't think we have a handful of VMs... because in a lot of cases, we need every bloody CPU cycle. For example, we have an SGI UV2000, a small, true supercomputer, 512 cores, 2TB RAM...and I see top telling me that one of my users's multithreaded parallel job has a load of it of 467 (and no, I'm not misplacing the decimal point....) mark
On 05/10/2016 01:29 PM, m.roth at 5-cent.us wrote:> Alice Wonder wrote: >> On 05/10/2016 12:19 AM, Johnny Hughes wrote: >>> On 05/10/2016 02:08 AM, Venkateswara Rao Dokku wrote: >>>> >>>> I would like to know whether the valid upgrade path will be present >>>> from CentOS 7 to future versions like we get for Ubuntu or some other >>>> operating systems. >>>> >>>> Right now, I am sure that we do not have proper update path in CentOS >>>> to move from one version to another. >>> >> I tend to keep all server content in /srv and all user content in /home >> >> Upgrading from one major version to another then is pretty simple - but >> not on the same machine. >> >> I do a fresh install of the new version in a new vm, make sure all the >> services are in place, and all the user and group ids match. > <snip> > I had an article published in the late, lamented SysAdmin magazine about > 10 years ago, where I recommended having a three of spare partitions, > doing an install using those for /, /usr and /boot - though now you could > get away with / and /boot. Then, if you had show-stopper issues, you could > always boot back via the old partitions. > > Where I work, I don't think we have a handful of VMs... because in a lot > of cases, we need every bloody CPU cycle. For example, we have an SGI > UV2000, a small, true supercomputer, 512 cores, 2TB RAM...and I see top > telling me that one of my users's multithreaded parallel job has a load of > it of 467 (and no, I'm not misplacing the decimal point....) >Ah - yes, different perspective I suppose. Vast majority of servers I manage are VMs purchased for a monthly fee from a service provider like linode. If you run the physical hardware yourself that is a completely different set of circumstances, point taken.