Netapp – Rename Filer in SnapMirror Relationship

As organizations change so do the standards which guide them.  As part of these changes pre-existing filers names may need to be updated and changed.  Before attempting to update a filers name you must first perform a number of confirmation steps.  This will ensure that you do not lose connectivity to your filer and that existing snapmirror relationships can be re-established after the change.

Prep

  • Create a new DNS entry for the new filer name
  • Prep the /etc/hosts file on the filer with the new name and IP (comment it out) on both source and destination filers.
  • Add the VLAN to the filers VIF or new VIF depending on how you’d like routing configured.
  • Prep the /etc/rc file with the new filer name and default gateway details.
  • Prep the NTP server details (only if a new server will be used on the new network…)
  • Confirm all management stations and NetApp monitoring utilities have access to filers new IP address. ie. add any necessary firewall rules.
  • Confirm network connectivity between the old and new network. This is critical if the filers name and IP address will only be changed on one site.

Execution (Note: during these steps all existing snapmirror relationships will disappear)

  1. Take note of the existing snapmirror relationships & their associated volume names
  2. Break the relationship (From the destination)
  3. Update the filers IP address, hostname, and default gateway
  4. Update the /etc/hosts file on the source and destination filer. It should reflect the new hostname and associated IP.
  5. Use ping to confirm both source and destination filer can see each other.
  6. BEFORE re-establishing the mirror relationship double check that the hosts file has been correctly updated on both the source and destination filer.
  7. Update your snapmirror options to allow the new filer names to establish relationships with each other.
  8. Re-Establish the mirror from the destination by using snapmirror resync.

Example:

nap003> snapmirror status
Snapmirror is on.
Source Destination State Lag Status
nap003:source_new nap004:dest_new Source 00:05:25 Idle

nap004> snapmirror status
Snapmirror is on.
Source Destination State Lag Status
nap003:source_new nap004:dest_new Snapmirrored 00:06:25 Idle

nap004> snapmirror break dest_new

Update both filers associated configuration files
nap003>rdfile /etc/rc
nap003>rdfile /etc/hosts
nap004>rdfile /etc/rc
nap004>rdfile /etc/hosts

nap004 /etc/hosts updates to make it nap006
192.168.0.201 nap006 nap006-e0a
192.168.0.200 nap005

nap004 /etc/rc updates to make it nap006
hostname nap006

nap004> hostname nap006
nap006>

Perform the same steps on the second filer. Once completed you can now re-establish the relationship from the destination filer. Do not be alarmed that the snapmirror status shows no relationships exist.

nap005> options snapmirror.access host=nap006
nap006> options snapmirror.access host=nap005

nap006> snapmirror resync -S nap005:source_new nap006:dest_new
The resync base snapshot will be: nap004(4055372815)_dest_new.4
These older snapshots have already been deleted from the source
and will be deleted from the destination:
nap004(4055372815)_dest_new.3
Are you sure you want to resync the volume? yes
Volume dest_new will be briefly unavailable before coming back online.
Wed Feb 13 22:43:13 EST [nap006:snapmirror.dst.resync.info:notice]: SnapMirror resync of dest_new to nap005:source_new is using nap004(4055372815)_dest_new.4 as the base snapshot.
Wed Feb 13 22:43:16 EST [nap006:wafl.snaprestore.revert:notice]: Reverting volume dest_new to a previous snapshot.
Revert to resync base snapshot was successful.
Wed Feb 13 22:43:17 EST [nap006:replication.dst.resync.success:notice]: SnapMirror resync of dest_new to nap005:source_new was successful.
Transfer started.
Monitor progress with ‘snapmirror status’ or the snapmirror log.

nap006> snapmirror status
Snapmirror is on.
Source Destination State Lag Status
nap005:source_new nap006:dest_new Snapmirrored 00:08:06 Idle

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NetApp – Rename SnapMirror Volumes

The goal of this post is to outline how to cleanly update the volume name of both the source and the destination volume of a NetApp snapmirror relationship.  These steps allow for  no loss of initialized snapmirror relationships and existing snapshots.

  1. Confirm the status of the snapmirror relationship is “idle” by running snapmirror status
  2. Rename the source and destination volume names
  3. Break the snapmirror relationship (Note: use the new destination volume name)
  4. Resync the snapmirror relationship using the new volume names

Example Step Output:
nap002> snapmirror initialize -S nap001:source_test nap002:dest_test
nap002> snapmirror status
Snapmirror is on.
Source Destination State Lag Status
nap001:source_test nap002:dest_test Snapmirrored 00:00:07 Idle

nap001> vol rename source_test source_new
nap002> vol rename dest_test dest_new

nap002> snapmirror status (Note: the source is now missing)
Snapmirror is on.
Source Destination State Lag Status
– nap002:dest_new Snapmirrored 00:01:49 Idle

nap002> snapmirror break dest_new
nap002> snapmirror resync -S nap001:source_new nap002:dest_new
The resync base snapshot will be: nap002(4055372815)_dest_test.1
Are you sure you want to resync the volume? yes

nap002> snapmirror status
Snapmirror is on.
Source Destination State Lag Status
nap001:source_test nap002:dest_new Snapmirrored 00:00:05 Transferring (84 KB done)

NetApp – SMB Tuning

Key NetApp settings to keep in mind when tuning CIFS/SMB performance.

• Use SMB 2.0 over SMB 1.0 wherever possible because SMB 2.0 provides better performance and more security than SMB 1.0.

• TCP Window Size: Set the value to 64K or more if SMB 2.0 is the protocol used.
options cifs.tcp_window_size 64240
Setting TCP window size to 2MB gives very good performance when combined with Windows 7 clients.

• Max outstanding requests per session (Max Mpx): Keep the Max mpx more than the 50 (the default).
This setting improves performance for parallel reads and writes. The values that can be set are 126, 253, or 1124.
options cifs.max_mpx <value>

• Negotiated Buffer Size: This setting controls the maximum negotiated read/write buffer size that can be used. The default is 32k and the size can also be set to 64k.
options cifs.neg_buf_size <value>

Source: NetApp SMB Best Practices Guide