Upgrade ZFS from 0.8 to 2.3.0 version

[drdrew75]

I'm going to upgrade an old server from ZFS 0.8 to version 2.3.0 and want to clarify a few key points before proceeding.

If anyone has experience upgrading from 0.8 to 2.3.0, I’d greatly appreciate your insights.

1. Are there any particular steps in the upgrade process, both before and after, besides running zpool upgrade?
2. Is it necessary to stop any load (read/write operations) on the filesystem during the upgrade?
3. Have there been any failures when upgrading ZFS to version 2.3.0 (data loss or corruption)?

[IvanVolosyuk]

Never used 0.7, but did a few ZFS upgrades before. So, I let others comment on 0.7 specifics, but here are a few general suggestions: - Upgrade module and userspace only, but don't do 'zpool upgrade' for at least a week to make sure everything works as expected with the new version of kernel module. - I don't know if 'zpool checkpoint' is available at 0.7, but it is very useful to checkpoint the entire pool state before 'zpool upgrade' and revert to an older version of zpool if necessary. - I would personally avoid 'zpool upgrade' at all and manually enable features I care about, but this can be a less tested configuration I guess. There is a 'compatibility' property which can be used to silence warnings that some features are available, but not enabled. - Make sure to update both userspace and the kernel module at the same time, otherwise there can be some incompatibilities between them. There can be quite a few changes in API between those for 0.7 .. 2.3 migration.

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On Tue, Feb 25, 2025 at 8:36 PM drdrew75 ***@***.***> wrote: I'm going to upgrade an old server from ZFS 0.8 to version 2.3.0 and want to clarify a few key points before proceeding. If anyone has experience upgrading from 0.8 to 2.3.0, I’d greatly appreciate your insights. 1. Are there any particular steps in the upgrade process, both before and after, besides running zpool upgrade? 2. Is it necessary to stop any load (read/write operations) on the filesystem during the upgrade? 3. Have there been any failures when upgrading ZFS to version 2.3.0 (data loss or corruption)? — Reply to this email directly, view it on GitHub <#17092>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABXQ6HMRHEGV2LCRCLY3YPL2RQ2R7AVCNFSM6AAAAABX2ERQOGVHI2DSMVQWIX3LMV43ERDJONRXK43TNFXW4OZYGAYTAOBXHE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>