upgrading server

[Andy So]

We have an old subversion version 1.4.3 (r23084) running on Solaris.
We would like to upgrade to use new hardware on Linux based OS (CentOS 6.9), possibly version 1.8.x or 1.9.x

Our plan is to installed and configure the latest SVN on CentOS 6.9. Then go through dump and load of the repository as described in various online post and documentations. The repository is quite large
guessing the size to be in the order of 20-40GB

Before we start undertaking such tasks

1. Does anyone know if there are there any problem/gotcha in migrating the repository?

2. Does anyone know how long it would take to export the repository of this size? This will give us an estimate how long to schedule down time and cut off time.

Thanks for any insight.

[Mark Phippard]

We have an old subversion *version 1.4.3 (r23084) *running on Solaris.
We would like to upgrade to use new hardware on Linux based OS (CentOS
6.9), possibly version 1.8.x or 1.9.x
Our plan is to installed and configure the latest SVN on CentOS 6.9. Then
go through dump and load of the repository as described in various online
post and documentations. The repository is quite large
guessing the size
to be in the order of 20-40GB
Before we start undertaking such tasks
1. Does anyone know if there are there any problem/gotcha in migrating the repository?
2. Does anyone know how long it would take to export the repository
of this size? This will give us an estimate how long to schedule down time
and cut off time.
Thanks for any insight.

Dump and load is a good idea because it lets the repository be rewritten
using the newer code and repository format which will give you a smaller
repository that will run a little faster. That said you do not HAVE to
dump/load. You have other options:

1. Just move the repository folder to the new server. Perhaps using tar
and then moving the archive.

2. Instead of using dump/load, use svnsync. This gives all the benefits of
the dump/load but allows you to shrink your downtime to almost nothing.
Just svnsync the repository to the new server. This will probably take a
long time, but it does not matter since the original server can be running
while it happens. At the time of your choosing, do a final svnsync, and
then shutdown the old server and use the new one.

3. Do option 1 now and then do a dump/load or svnsync at some future time
that is more convenient for downtime. It will probably run faster since it
is on new and better hardware too.

There are some gotchas no matter what:

1. Does the new server have a new hostname or do you intend to update DNS
to point to new server? If you are not doing the latter, then all of your
existing working copies and scripts have to be modified for the new
server. Also any use of svn:externals property has to be modified.

2. With an old repository there is a good chance you will run into bugs in
your data that cause svnsync or load to fail. There are workaround for
different failures but be prepared to run into them and account for finding
the solutions. SVN 1.8 and 1.9 have added various options to let you
workaround some of the known bugs. A common problem is having svn:
properties that are not UTF-8 encoded or do not have LF line endings.
svnsync has this option to work around the encoding problem:

--source-prop-encoding ARG : convert translatable properties from encoding
ARG
to UTF-8. If not specified, then properties are
presumed to be encoded in UTF-8.

And it automatically fixes the LF problems.

svnadmin load does not have any options to fix the problems, but you can
add the --bypass-prop-validation option to ignore them and just carry
the problems into your new repository.

[David Chapman]

We have an old subversion /version 1.4.3 (r23084) /running on Solaris.
We would like to upgrade to use new hardware on Linux based OS (CentOS
6.9), possibly version 1.8.x or 1.9.x
Our plan is to installed and configure the latest SVN on CentOS 6.9.
Then go through dump and load of the repository as described in
various online post and documentations. The repository is quite
large
guessing the size to be in the order of 20-40GB
Before we start undertaking such tasks
1.Does anyone know if there are there any problem/gotcha in migrating
the repository?
2.Does anyone know how long it would take to export the repository of
this size? This will give us an estimate how long to schedule down
time and cut off time.
Thanks for any insight.

I recommend CentOS 7.x; CentOS 6.x is nearing the end of its support
lifetime. I also installed an SSD on my new machine - much faster than
rotating media, and Subversion's "write once" philosophy (old revisions
are essentially immutable) works well on an SSD.

[Andrew Reedick]

Post by Andy So
Does anyone know how long it would take to export the repository of this size? This will give us an estimate how long to schedule down time and cut off time.

Svnsync is the easy option.

If you insist on doing a dump/load, then a) you can time a test run of a dump/load, and b) "svnadmin dump" allows you to specify revision ranges which means you can do incremental dumps. You can dump/load the bulk of the repo now and then during the migration, run another dump/load to catch any new commits.
http://svnbook.red-bean.com/nightly/en/svn.reposadmin.maint.html#svn.reposadmin.maint.migrate

The only caveat I can think of is if someone changes revision properties (e.g. the commit message) between the time of the initial dump and the migration. But you can track/prevent those with a hook script. (And is another reason why svnsync is pref

[Ryan Schmidt]

Don't forget that svnadmin dump/load and svnsync don't preserve hook scripts or other ancillary data that might be in your repository directory on the server, so if you have hook scripts, authorization rules or other customizations, carry those over to the new server manually. And of course any configuration files for httpd or svnserve.