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 (latest version) to Lustre 1.8.x (latest version).
• Lustre 1.8.x (any minor version) to Lustre 1.8.x (latest version).

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 Lustre 1.6.x (latest version?).
• If you upgrade from one minor version to the next (for example, Lustre 1.8.0 >

1.8.x), you can downgrade to the earlier minor version (Lustre 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.

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.

Lustre Manual Version	Supported Lustre Version
Lustre_1.4.8.1_man_v37	1.4.10
	1.4.9
	1.4.8
Lustre_1.4.8.1_man_v37	1.4.10
	1.4.9
	1.4.8
Lustre_1.4.8.1_man_v37	1.4.10
	1.4.9
	1.4.8

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.

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

Upgrading Clients

• 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

You can start a new client with an old MDT by using the old format of the client mount command:

client# mount -t lustre <mdtnid>:/<mdtname>/client <mountpoint>

You can start a new client with an upgraded MDT by using the new format and pointing it at the MGS, not the MDT (for co-located MDT/MGS, this is the same):

client# mount -t lustre <mgsnid>:/<fsname> <mountpoint>

Old clients always use the old format of the mount command, regardless of whether the MDT has been upgraded or not.

Upgrading a Single File System

tunefs.lustre will find the old client log on an 1.4.x MDT that is being upgraded to 1.6. (If the name of the client log is not "client", use the lustre_up14.sh script, described in Step 2 and Step 3.)

1. Shut down the MDT.

mdt1# lconf --failover --cleanup config.xml

2. Install the new Lustre version and run tunefs.lustre to upgrade the configuration.

There are two options:

• Rolling upgrade keeps a copy of the original configuration log, allowing immediate reintegration into a live file system, but prevents OSC parameter and failover NID changes. (The writeconf procedure can be performed later to eliminate these restrictions. For details, see Running the Writeconf Command.)

mdt1# tunefs.lustre --mgs --mdt --fsname=testfs /dev/sda1

• i.--writeconf begins a new configuration log, allowing permanent modification of all parameters (see Changing Parameters), but requiring all other servers and clients to be stopped at this point. No clients can be started until all OSTs are upgraded.

[root@mds1]# tunefs.lustre --mgs --writeconf --mgs --mdt --
fsname=ldiskfs /dev/hda4
checking for existing Lustre data: found CONFIGS/mountdata
Reading CONFIGS/mountdata
Read previous values:
Target: testfs-MDT0000
Index: 0
UUID: mds-1_UUID
Lustre FS: testfs
Mount type: ldiskfs
Flags: 0x205
(MDT MGS upgrade1.4 )
Persistent mount opts: errors=remount-ro,iopen_nopriv,user_xattr
Parameters:
Permanent disk data:
Target: ldiskfs-MDT0000
Index: 0
UUID: mds-1_UUID
Lustre FS: ldiskfs
Mount type: ldiskfs
Flags: 0x305
(MDT MGS writeconf upgrade1.4 )
Persistent mount opts: errors=remount-ro,iopen_nopriv,user_xattr
Parameters:
Writing CONFIGS/mountdata
Copying old logs

3. Start the upgraded MDT.

mdt1# mkdir -p /mnt/test/mdt
mdt1# mount -t lustre /dev/hda4 /mnt/test/mdt
mdt1 # df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/hda2 10080520 4600820 4967632 49% /
/dev/hda1 101086 14787 81080 16% /boot
none 501000 0 501000 0% /dev/shm
/dev/hda4 23339176 455236 21550144 3% /mnt/test/mdt

4. Upgrade and start the OSTs for the file system in a similar manner, except they need the address of the MGS. Old installations may also need to specify the OST index (for instance, --index=5).

ost1# tunefs.lustre --ost --fsname=lustre --mgsnode=mds /dev/sda4
checking for existing Lustre data: found last_rcvd
tunefs.lustre: Unable to read /tmp/dirQi2cwV/mountdata (No such
file or directory.)
Trying last_rcvd
Reading last_rcvd
Feature compat=2, incompat=0
Read previous values:
Target:
Index: 0
UUID: ost1_UUID
Lustre FS: lustre
Mount type: ldiskfs
Flags: 0x202
(OST upgrade1.4 )
Persistent mount opts:
Parameters:
Permanent disk data:
Target: lustre-OST0000
Index: 0
UUID: ost1_UUID
Lustre FS: lustre
Mount type:ldiskfs
Flags: 0x202
(OST upgrade1.4 )
Persistent mount opts: errors=remount-ro,extents,mballoc
Parameters: mgsnode=192.168.10.34@tcp
Writing CONFIGS/mountdata 11.1.5 Upgrading Multiple File Systems
with a Shared MGS
Ost-1# mount -t lustre /dev/sda4 /mnt/test/ost/
Ost1# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda2 10080520 3852036 5716416 41% /
/dev/sda1 101086 14964 80903 16% /boot
none 501000 0 501000 0% /dev/shm
/dev/sda4 101492248 471672 95781780 1% /mnt/test/ost

Upgrading Lustre 1.8.x to the Next Minor Version

To upgrade Lustre 1.8.x to the next minor version, for example, Lustre 1.8.0.1 > 1.8.x, follow these procedures:

• To upgrade the complete file system or multiple file system components at the same time, requiring a file system shutdown, see Performing a Complete File System Upgrade
• To upgrade one Lustre component (server or client) at a time, while the file system is running, see Performing a Rolling Upgrade

More Information

See Chapter 13 in the Lustre Operations Manual for information about:

• Downgrading from Lustre 1.8.x to Lustre 1.6.x