Migrating Legacy v3 (CentOS) to “Built on openSUSE”¶
Rockstor v3 was based on CentOS 7 and is no longer supported. Last updates per channel:
Stable (3.9.2-57) - April 2020
Testing (3.9.1-16) - November 2017
Starting with v4, Rockstor is “Built on openSUSE”. See: openSUSE:Trademark guidelines.
Our downloadable installers aim to have late stable release candidate (RC), or first published stable channel ‘rockstor’ packages pre-installed. Below is a non-exhaustive list of notes, recommendations, and warnings for those planning on going through the upgrade process.
Migration overview¶
Note
All v3 (and likely earlier) Pools and Configuration Backup and Restore files (once downloaded), are expected to import and restore respectively as they would in a v3 install. It is important to import all pools before uploading and applying a config save file.
Note
As of 3.9.2-56, in common with many NAS systems, the Apple Filing Protocol (AFP) was dropped.
Note
As from 5.0.9 “Built on openSUSE” versions no longer auto-import the system pool. This is intended to discourage the use of the system Pool for data storage. But when imported (advanced users only) this pool is labeled “ROOT”. Prior to v4 the system Pool was labeled “rockstor_rockstor”. Starting with v4 the inadvertent appearance of the “root” share/subvolume has also been removed.
Warning
As this migration requires an operating system re-install, it is imperative to ensure that backups have been created/refreshed and verified. Greater hardware compatibility is assumed given the years newer kernel. But there is always the possibility of regressions.
Warning
It is also possible, although unlikely, that once a pool is imported under a newer kernel, it may fail to import as read-write (rw) in the older v3 related kernel.
Use a new system disk¶
It is highly advisable to install the “Built on openSUSE” version onto a fresh system disk. This leaves open the possibility of re-attaching the old v3 system disk in case of any difficulties. Do not leave an old v3 system disk attached while installing a “Built on openSUSE” version; unless the same system disk is reused (not advised but entirely possible). The Rockstor’s “Built on openSUSE” installer is significantly faster and simpler than a v3 install, but will destroy all data on the target disk. Hence the advise here to preserve the original system disk and to detach it prior to the new install.
Warning
If, for whatever reason, there is a need to revert to the v3 system disk, avoid having more than one Rockstor system disk, of any version, attached simultaneously. This causes known confusion within the current and past versions of the Web-UI. This inflexibility will be improved in time.
Disconnect all Data disks¶
As a purely precautionary measure, it is highly advisable that all data disks be detached prior to the new install. Take careful note of their connections to the host system. This connection concern relates to potential hardware compatibility of these interconnects. Btrfs, our underlying file system and device manager, is not normally concerned with such changes, but the existing hardware pairings, assuming prior function, are best noted nevertheless. Just in case, after the last shutdown of v3, while attaching the new system disk, be sure to unplug all prior disks. This is simply to avoid an accidental selection of a data pool member for the fresh installs’ system disk.
Revised Installer¶
See Rockstor’s “Built on openSUSE” installer for a step-by-step explanation and guide.
Warning
The Rockstor’s “Built on openSUSE” installer will wipe all prior data on the target disk selected. A simple quick mistake at the initial Select Installation Disk step could inadvertently destroy a pool member’s data.
If the prior Disconnect all Data disks section’s advise is followed, there will only be one attached proposed system disk anyway.
Once the new install is in place, it is advisable to apply all upstream updates. See: Install updates from the Web-UI. Take care to ensure these have all been applied prior to rebooting. The Dashboard can help to determine this by observing the network and CPU activity. There is an outstanding bug where our ‘wifi-like’ busy indicator does not last the duration of the installs.
Ensure that the system reboots and returns as expected before re-attaching all prior data Pool/s members. Be sure to re-connected prior Pool members as before, prior to Pool/s import. And only attempt config restore after having successfully imported any prior data Pools.
V3 Pool/s import¶
The newer Pool import feature, although improved, is compatible with importing Pools created under a v3 (and earlier) Rockstor version. See: Import BTRFS Pool.
Warning
See also Import unwell Pool in case a pool requires special mount options.
V3 Config save files¶
“Built on openSUSE” versions can restore v3 config saves. See: Configuration Backup and Restore.
Note
Ensure to first download the v3 saved config as they otherwise reside on the system disk.
Warning
Although older config save files are compatible, there has been much work done on extending this features capability. Earlier config saves cover less elements of the system than later ones. E.g., Rock-ons installed and their associated share settings are not included in config saves before 3.9.2-52. Note that Rock-ons restore capability depends upon a non-system disk The Rock-ons root share location.
Other differences¶
Many bug fixes¶
In the process of moving from a CentOS base to a “Built on openSUSE” one, the developers have found and fixed a large number of bugs, and inherited such things as our Rockstor 4 Installer Recipe that trivially enables highly customised installer creation. There is also now ARM64 (e.g. Pi4/Ten64) compatibility, baring some Rock-ons, courtesy of openSUSE’s extreme heritage in ARM support.
Also note the following, Rockstor has moved past the Jump initiative:
In v3 the upstream of CentOS had in turn its upstream of RedHat’s RHEL.
openSUSE has in turn its binary compatible upstream of SuSE SLES.
If the prior v3 install has a customization involving a CentOS/RHEL compatibility, that should also be used on the “Built on openSUSE” version, check first for an openSUSE equivalent, and then for a SLES equivalent. Note that often packages are named differently between linux distributions, so it may require some detective work to find the matching package to install. This most likely only affects advanced users and should not be a concern when using Rockstor’s built-in capabilities.
Users and default group¶
Since the underlying OS has changed between v3 and v4 onwards, there are other more subtle differences that may only come to light in time. One such difference is the default use of the “users” group in openSUSE for newly added users. Our prior CentOS base defaulted to individual user group creation named after the user concerned. It is thought that the newer default is more suited to a shared resource, though this difference may come as a surprise to prior v3 administrators.
