LCTL-REPLACE_NIDS(8)

NAME
lctl-replace_nids - Replace LNet NIDs for an MDT or OST

SYNOPSIS
lctl replace_nids DEVICE_NAME NODEA_NID1[,NODEA_NID2[:NODEB_NID1,NODEB_NID2...]]

DESCRIPTION
The lctl replace_nids command is used to replace Network Identifiers (NIDs) in a Lustre file system.

This is useful when a server's network address changes and you need to update the file system configuration to reflect the new address.

This command must be run on the MGS node. Only MGS server should be started (command execution returns error in another case).

To start the MGS service only: mount -t lustre MGT_DEVICE -o nosvc,noclient MOUNT_POINT

Note the replace_nids command removes any invalidated records in the configuration log. The previous log is backed up with the suffix '.bak'.

Failover nids must be passed after ':' symbol. More then one failover can be set (every failover nids after ':' symbol).

The replace_nids command differs from tunefs.lustre --writeconf in that it does not erase the entire configuration log, precluding the need to "writeconf" all servers and re-specify all permanent parameter settings.

OPTIONS

DEVICE_NAME
    Device name there changes applied to.

NODEA_NID1
    Primary node first NID

NODEA_NID2
    Primary node second NID

NODEB_NID1
    Failover node first NID

NODEB_NID2
    Failover node second NID

EXAMPLES
To replace an old NIDs for device lustre-MDT0000 with new one use the following command:
    # lctl replace_nids lustre-MDT0000 192.168.1.112@tcp1, 169.254.161.205@tcp2:192.168.1.113@tcp1, 169.254.161.206@tcp2:192.168.1.114@tcp1, 169.254.161.207@tcp2

192.168.1.112@tcp1,169.254.161.205@tcp2 - primary NIDs
192.168.1.113@tcp1,169.254.161.206@tcp2 - NIDs of first failover node
192.168.1.114@tcp1,169.254.161.207@tcp2 - NIDs of second failover node

AVAILABILITY
lctl replace_nids is part of the lustre(7) filesystem package since release 2.4.0

SEE ALSO
lustre(7), lctl(8), tunefs.lustre(8)