Upgrading to a New Version of Lustre

This section provides information about supported upgrades, upgrade paths, and interoperability of nodes with different versions of Lustre installed. It also describes procedures for upgrading your Lustre file system to a new version of Lustre. For information about available releases, see Lustre Release Information.

Supported Upgrades

For Lustre 1.8.x, the following upgrades are supported:

• Lustre 1.6.x to Lustre 1.8.0.
• One minor version to the next (for example, 1.8.0 > 1.8.x). [[Should this say 1.8.0 > 1.8.1?]] Or is it OK to skip over a minor release?

For Lustre 1.8.0, if you have upgraded from an earlier version, you can downgrade to that version or any version in between?. For example:

• If you upgrade from Lustre 1.6.x > 1.8.0, you can downgrade to version 1.6.x. Can 1.6.x be any version of 1.6?
• If you upgrade from one minor version to the next (for example Lustre 1.8.0 > 1.8.x), you can downgrade to an earlier minor version (e.g., version 1.8.x). Should this say ...? If you upgrade from one minor version to the next (for example, Lustre 1.8.0.1 > 1.8.1), you can downgrade to an earlier minor version (e.g., version 1.8.0.1 or 1.8.0).

To downgrade from 1.8.x to 1.6.x, see More Information.

Caution: A new installation of Lustre 1.8.x is not guaranteed to be downgradeable to an earlier Lustre version Does this mean you may not be able to downgrade to 1.8.0 or does it mean you may not be able to downgrade to a 1.6.x version?).

Note: If you are upgrading from Lustre 1.4.6 or later to Lustre 1.6, see Upgrading from 1.4.6 and later to 1.6

Supported Upgrade Paths

Two Lustre upgrade paths are supported. Either can be applied to the entire file system or a combination of the two can be used to upgrade individual servers and clients.

• Rolling upgrade - Individual servers (or their failover partners) and clients are upgraded one at a time and restarted, so that the file system never goes down. This type of upgrade limits the ability to change certain parameters.
• Entire file system upgrade - All servers and clients are shut down and upgraded at the same time.

Interoperability between Nodes with Different Versions of Lustre Installed

Interoperability between clients, OSTs, and MDTs with different versions of Lustre installed is described below.

Does "old" mean a node with any older version of Lustre installed or just 1.6.x?

Does "new" mean specifically 1.8.x??

Does "mixed" mean a group of servers, some with older versions of Lustre and some with newer versions of Lustre installed?

Clients

• Old live clients can continue to communicate with old/new/mixed servers.
• Old clients can start up using old/new/mixed servers.
• New clients can start up using old/new/mixed servers (use old mount format for

old MDT).

OSTs

• New clients/MDTs can continue to communicate with old OSTs.
• New OSTs can only be started after the MGS has been started (typically this

means "after the MDT has been upgraded.")

MDTs

• New clients can communicate with old MDTs.
• New co-located MGS/MDTs can be started at any point.
• New non-MGS MDTs can be started after the MGS starts.

Interoperability limitations:

• Old clients cannot mount a file system which was created by a new MDT.

• If your file system was originally created using Lustre 1.8.x, you will not be

able to mount the (a?) file system created using an earlier Lustre version. However, if your system has been upgraded from 1.6.x to 1.8.x, you can mount Lustre clients on both Lustre versions. Lustre 1.8.x clients are interoperable with 1.6.x servers.

Find a place for this note Note: In Lustre version 1.6 and later, the file system name (--fsname parameter) is limited to 8 characters so that it fits on the disk label.

Prerequisites to Upgrading Lustre

This content was in the OM section "Upgrading from Lustre 1.6.x to Lustre 1.8.0"

What are these procedures? Do they need to be completed before the upgrade is started?

Remember the following points before upgrading Lustre.

The MDT must be upgraded before the OSTs are upgraded. summarize steps in a sentence

1. Shut down lconf failover.

2. Install the new modules.

3. Run tunefs.lustre.

4. Mount startup.

A Lustre upgrade can be done across a failover pair. - In a failover pair, do the backup server first

1. On the backup server, install the new modules.

2. Shut down lconf failover.

3. On the new server, run tunefs.lustre.

4. On the new server, mount startup.

5. On the primary server, install the new modules.

Upgrade procedures

Which topics should be included in the wiki topic and which referred to in the manual (Chapter 13)?

Upgrading from Lustre 1.6.x to Lustre 1.8.0

• Prerequisites to Upgrading Lustre (see section above)
• Starting Clients - if upgraded client only would need to know how to start a new client with an old MDT - says use old command - relevant depending on which machines you start with - if you start with clients you need to know this information. Need instructions on upgrading a clientsee initial client install ch 3 - intermingled - discuss with Sheila - something missing
• Upgrading a Single File System X

Upgrading Lustre 1.8.0 to the Next Minor Version X

section will change for every release substantial content for 1.8 - 2.0

More Information

See the Lustre Operations Manual for information about:

• Upgrading Multiple File Systems with a Shared MGS
• Downgrading from Lustre 1.8.0 to Lustre 1.6.x