Showing posts with label cdot. Show all posts
Showing posts with label cdot. Show all posts

Monday, December 9, 2019

Netapp: How to do perform Disk Erasure, Disk Clearing and Wipe Configuration on CDOT Netapp disks.

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Depending on what scenario is applicable to you in your environment, there are two ways to run data erasure and disk configuration wipe out activity. By simply pushing the data disk to spare pool after removing it from aggregate may not suffice some of the data erasure function requirement. Disk degaussing by feeding the drive into traditional degauss machine that uses magnetic function to certify degauss might leave some data owners in a questionable position about their comfort before disk disposal. Here are two scenarios that are standard practices which Netapp supports without intervention from third party software or application that runs disks data erasure and wiping configuration.

Scenario 1 Usage: Disk Initialize
If there is flexibility to reboot the node and entire disks data needs to be wiped or configuration reset, then “disk Initialize” is the right option.

Prerequisites.
1. If the disks are part of an aggregate and/or holds volumes, volumes must be taken offline, destroyed followed by taking aggregate offline and aggregate deletion.
2. Disks must be in a spare pool, but can be owned by nodes.
3. Only root aggregate disks should be present.

Actual Action:
Step 1. Boot each node by while accessing from console or SP (if configured) and take it to the loader prompt.
Boot each node to the LOADER/CFE prompt and ensure that the below variables are set. These variables remove the cluster RDBs, CDBs and the varfs from mroot, boot device and nvram.
setenv bootarg.init.boot_clustered true
setenv bootarg.factory_init_completed true
setenv bootarg.init.clearvarfsnvram true

Step 2. Then run boot_ontap from loader prompt and while node reboots, Press CTRL + C to go to special boot menu.

Step 3. Out of 8 special boot menu option, dont select any option yet. Rather Type “wipeconfig” on each node.

Step 4. Then select Option no. 4. that says “Clean configuration and initialize all disks”
(This will prompt if you want to zero disks, reset config and install a new file system. Type “yes”)

Step 5. This will run disk initialize operation in the background which is indicated by dots (…….) fillling the screen till its done. Each and every drives gets initialized and upon completion, it will take you to a prompt where it asks if you want to create or join cluster or new filesystem.

At this time, it is safe to power down Controller head and Disk Shelves. Disk have been reset and data have been completely erased.


Scenario 2 Usage: Disk Sanitization
Data ONTAP 8.0 and earlier, the disk sanitization feature needed a disk sanitization license.
Data ONTAP 8.1 and later, Just need to enable the feature per step 1, under Actual Action below.
If you only few drives in a stack, or just one shelf from a set of stack of shelves, you cannot use scenario 1 based solution for complete data erasure as we are not going to erase data from entire array, but only from selective disks.
Disk sanitization is the process of physically obliterating data by overwriting disks with specified byte patterns or random data so that recovery of the original data becomes impossible. You use the sanitization process to ensure that no one can recover the data on the disks. This functionality is available through the nodeshell.

Pre-Requisites.
1. Disks in question must be in spare pool, but can be owned by nodes.

How Disk sanitization works?
Disk sanitization process uses three successive default or user-specified byte overwrite patterns for up to seven cycles per operation. The random overwrite pattern is repeated for each cycle.

**Sanitization contains two phase:
a. Formatting phase
b. Pattern overwrite phase

**Disk Sanitization Feature is applied at Storage system level, and once it is enabled, it cannot be disabled.

Actual Action:
Step 1. Go to nodeshell from cluster.
node::>options nodescope.reenabledoptions licensed_feature.disk_sanitization.enable
node::>options licensed_feature.disk_sanitization.enable on

Step 2.Start disk sanitize on disk or disklist.
node::> disk sanitize start disk_list

Step 3. Check disk sanitize status
node::> disk sanitize status disk_list

Step 4. After disk sanitization is complete, return the sanitized disk to spare pool, it wont automatically send disk to spare pool.
node::> disk sanitize release disk_name

Step 5. Exit from node shell and go to cluster shell.
node::> CTRL + D
Cluster::>>

Step 6. Verify disk have been properly placed on spare pool.
cluster::> storage disk show -container-type spare

By now, disk is sanitized with no data and is in hot spare pool for it be ready to be used.

**At this time, you can use the degauss machine to crush the drive**

**Some of the Industry Standards on how to run disk sanitization or data erasure procedure**

https://kb.netapp.com/app/answers/answer_view/a_id/1034565/~/how-to-use-disk-sanitize-to-meet-department-of-defense-5220.22m-
https://kb.netapp.com/app/answers/answer_view/a_id/1072424/~/how-to-perform-disk-erasure%2C-disk-clearing-and-disk-sanitization-

You are Welcome :)

Tuesday, November 26, 2019

Netapp: How to remove Nodes from multi-node cluster running CDOT with Examples


I am a seasonal IT professional with a background on VMware, Storage, Backup, Unix, and Project liaison experience. I have held positions working on technologies like Netapp, EMC, IBM, Cohesity storage and Backup supporting SAN and NAS Environment. I have held roles of IT administrator, engineer, team lead and project liaison. This blog is for Storage and Backup Professionals, and content are derived from vendor as well as my own experience.
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I recently did cluster unjoin and removed nodes from multi-node cluster running CDOT 9.3Px without any service disruption and with seamless activities. 

##Visibility to system is the KEY. Log into SP or Console of nodes all the time during this activity. Helps if you run into some unforeseen or unpredicted situations.


Prerequisites:
  1. Disable Storage failover (cf status) between HA nodes.
  2. Migrate data lifs home and home port from nodes in question over to other healthy nodes/ports by net interface modify.
  3. Remove ports of nodes from broadcast domain / failover-groups leaving only ones that would be present after nodes removal.
  4. Delete intercluster lifs, and remove Intercluster ports from corresponding broadcast domain.


Actual Steps:

Step 1. 
Log into adv mode in cluster by:
cluster: set advanced
Warning: These advanced commands are potentially dangerous; use them only when directed to do so by NetApp personnel.
Do you want to continue? {y|n}: (Press y)

Step 2. 
Confirm that the nodes in questions is serving as master node. If it is working as master node, make it ineligible. (Caution, Once you have it made it ineligible, you would need to reboot the node to make it eligible again, if you need to.) This can be done by checking cluster ring status from adv mode.
cluster*::>cluster ring show

Verify that there is still no lif or data on nodes in question:
net int show -home-node node1

net int show -home-node node2

cluster*::> cluster modify -node node2 -eligibility false
Double confirm by running below to ensure there is no lif dependency except cluster port and/or node management port/lif. It would complain if there is still something left on nodes being worked.

cluster*::>cluster ring show
(This would list node2 being offline as it has been deemed ineligible. Other node will display as master)
(You run the same for both nodes in HA.)


Node      UnitName Epoch    DB Epoch   DB Trnxs      Master    Online
---------     --------      -------       --------       --------           ---------      ---------
node2     mgmt         0               25       736267                           offline
node2     vldb           0               23       1913                               offline
node2     vifmgr        0               25       11031                             offline
node2     bcomd       0               26       4                                     offline
node2     crs             0               23       1                                     offline

Step 3.  Verify:
cluster::*>storage failover show
cluster::*>cluster ring show

Step 4. 
Now run actual unjoin action.
cluster::*> cluster unjoin -node node2

(This will provide some warnings, but as long as checklist of pre-req and other is completed, proceed)

(At this time, you can wipe disk data by pressing step 4 by doing “Ctrl + C” during reboot. You will have visibility to console, if you have been accessing the node via console or service processor. It is strongly advised, that nodes in question be accessed using sp in a different session than actual session where cluster unjoin session is being executed.)

Step 5. 
Halt the nodes in question by logging into individual nodes, if applicable. You can uninstall the Hardware after completion of disk initialization (if chosen). Otherwise, its safe to remove cables, uninstall hardware.



You are welcome :)