Pass the Netapp NetApp Certified Data Administrator NS0-155 Questions and answers with CertsForce

http://vipulvajpayeestorage.blogspot.com/2012/01/manually-failover-activity-in-netapp.html

In order to test or effect a Disaster Recovery operation, you must restrict access to the disaster site node to prevent the node from resuming service. If you do not, you risk the possibility of data corruption.

Access to the disaster site note can be restricted in the following ways:

Turn off the power to the disaster site node Use "manual fencing" (Disconnect VI interconnects and fiber channel cables; either physically or through configuration changes on the fabric switches.)

Isolating the failed node from the surviving node could still lead to the possibility of a split brain, so this is not a correct answer.

Sadly, you cannot convert a LUN into a Vulcan Language Dictionary.

https://library.netapp.com/ecmdocs/ECMP1210206/html/GUID-A865DB95-9418-4ED2-A993-74F347F674A0.html

1. Validate that you can access the remote storage by entering the following command:

aggr status -r

Note: A (level-0 resync in progress) message indicates that a plex cannot be rejoined.

2. Turn on the power to the node at the disaster site. After the node at the disaster site boots up, it displays the following:

Waiting for giveback...(Press Ctrl-C to abort wait)

3. If the aggregates at the disaster site are online, take them offline by entering the following command for each aggregate that was split:

aggr offline disaster_aggr

disaster_aggr is the name of the aggregate at the disaster site.

Note: An error message appears if the aggregate is already offline.

4. Destroy every target plex that is in a level-0 resync state by entering the following command:

aggr destroy plex_name

5. Re-create the mirrored aggregates by entering the following command for each aggregate that was split:

aggr mirror aggr_name -v disaster_aggr

aggr_name is the aggregate on the surviving site’s node.

disaster_aggr is the aggregate on the disaster site’s node.

The aggr_name aggregate rejoins the disaster_aggr aggregate to reestablish the MetroCluster configuration.

6. Enter the following command at the partner node:

cf giveback

The node at the disaster site reboots.

https://communities.netapp.com/groups/chris-kranz-hardware-pro/blog/2009/03/05/fractional-reservation--lunoverwrite

From the article:

"If you reduce the Fractional Reservation to 0, you need to make sure the rate of change is within the volume size, or you need to make sure the volume can auto-grow when required or even snap auto-delete to reduce the reserved blocks and free up space (although I am not a huge fan of snap auto-delete for various reasons)."

iSCSI and Fiber Channel encapsulate SCSI protocol, simulating direct disk access. These are commonly referred to as a block storage protocols. FCoE is another such protocol.

CIFS and NFS, HTTP and FTP provide file access not block access.

https://library.netapp.com/ecmdocs/ECMP1196986/html/GUID-87340429-8F4A-4AA6-B081-0F5040089C78.html

Data compression requires 64-bit aggregates.

https://library.netapp.com/ecmdocs/ECMP1196979/html/man1/na_snapvault.1.html

http://www.geekyfacts.com/index.php?option=com_content &view=article&id=64:snapvault

snapvault snap sched [ -f ] [ -x ] [ -o options ] [ volname [ snapname [ schedule ]]]

schedule is cnt[@day_list][@hour_list] or cnt[@hour_list][@day_list]

In the schedule, cnt tells SnapVault how many of the snapshots to keep for primaries and for non-SnapLock secondary volumes. The snapshots will be numbered newest to oldest from 0 to cnt-1. When creating a new snapshot, SnapVault will delete the oldest snapshots, increment by one the number on the remaining snapshots and then create a new number 0 snapshot. If a snapshot is missing from the sequence (e.g. sv.0, sv.1, and sv.3 exist but sv.2 does not), only snapshots that need to be renumbered to make room for the new sv.0 snapshot will be renumbered. In the example, sv.0 and sv.1 would be renamed to sv.1 and sv.2, but sv.3 would remain unchanged.

The cnt in the schedule is interpreted differently for SnapVault secondary SnapLock volumes. For SnapLock secondary volumes, snapshots are created with a name that includes an encoded date and time of when the snapshot is created. These snapshots are never renamed and they are never automatically deleted. These snapshots may be deleted using snap delete after the retention period of the snapshot has expired. If cnt is 0, no snapshots will be taken. If cnt is any non-zero value, snapshots will be taken and no snapshots will be automatically deleted.

If specified, the day_list specifies which days of the week the snapshot should be created. The day_list is a comma-separated list of the first three letters of the day: mon, tue, wed, thu, fri, sat, sun. The names are not case sensitive. Day ranges such as mon-fri can also be given. The default day_list is mon-sun, i.e. every day.

If specified, the hour_list specifies which hours of the day the snapshot should be created, on each scheduled day. The hour_list is a comma-separated list of the hours during the day, where hours are integers from 0 to 23. Hour ranges such as 8-17 are allowed. Also, step values are allowed in conjuction with ranges. For example, 0-23/2 means "every two hours". The default hour_list is 0, i.e. midnight on the morning of each scheduled day.

https://library.netapp.com/ecmdocs/ECMP1196986/html/GUID-E5AD37DE-2F44-47DB-90A3-C8E115FCBFB7.html

SnapVault replicates at the file level not the block level.

Deduplication is always a post-processed activity for Data OnTap, while compression is an inline process.

The deduplication schedule depends on the SnapVault update schedule on the destination system.

A new Snapshot copy replaces the archival Snapshot copy after deduplication finishes running on the destination system. (The name of this new Snapshot copy is the same as that of the archival copy, but the Snapshot copy uses a new timestamp, which is the creation time.)

The SnapVault update recognizes the deduplicated blocks as changed blocks. Thus, when deduplication is run on an existing SnapVault source for the first time, all saved space is transferred to the destination system.

https://library.netapp.com/ecmdocs/ECMP1196979/html/man1/na_fcp.1.html

fcp show adapter [ -v ] [ adapter ]

If no adapter name is given, information about all adapters are shown.

This command displays information such as nodename/portname and link state about the adapter.

If the -v flag is given, this command displays additional information about the adapters.

http://www.netapp.com/us/media/tr-3326.pdf

http://backdrift.org/man/netapp/man5/na_snapmirror.conf.5.html

http://hd.kvsconsulting.us/netappdoc/733docs/html/ontap/onlinebk/GUID-47724B21-7C7E-4AC9-A497-9505B42C27AF.html

With SnapMirror Sync and SnapMirror Semi-Sync, changes to the source volume do not show up immediately on the destination volume, even though the changes have been replicated. The changes are first shown after the source system creates an automatic Snapshot copy of the source volume.

Snapshot copies created on the source volume are immediately propagated to the destination volume. The automatic Snapshot copies are created every three minutes by default.

To change the interval for automatic Snapshot copies, change the visibility_interval in the

snapmirror.conf file; however, performance can degrade if set to a smaller interval because frequent

Snapshot copies cause additional processing such as cache consistency checking on the destination system.

There is also a disadvantage in setting this to a large value. When the connection between the systems has an outage and SnapMirror goes into asynchronous mode, SnapMirror uses the last common Snapshot copy to transition into synchronous mode. This means that all data from the last valid common Snapshot copy will need to be replicated from the source to the destination storage system. If the visibility_interval is set to a large value, a large amount of data might have to be transferred and it might take longer time for SnapMirror to transition into synchronous mode. For these reasons, keep the default value of three minutes.

visibility_interval

The value for this argument is a number optionally followed by the suffixes: s (seconds), m (minutes) or h (hours). If a suffix is not specified, value is interpreted as seconds. This argument controls the amount of time before an automatic snapshot is created on the source volume that is synchronously mirrored. The value is the number of seconds between automatically created snapshots. The default value is 3 minutes. A small number here can negatively affect the performance of the mirror. This argument is ignored for asynchronous mirrors.

visibility_interval={xs | xm | xh}

Determines the amount of time before an automatic Snapshot copy is created on the source volume that is being replicated using synchronous or semi-synchronous SnapMirror. When replicating synchronously or semisynchronously, using SnapMirror, changes to the source volume do not show immediately on the destination volume, even though the changes have been replicated. The changes are shown only after the source system takes an automatic Snapshot copy of the source volume. This event occurs every three minutes by default.

You can change the interval for automatic Snapshot copies, but performance can degrade if you set smaller intervals because Snapshot copies are taken more often. The smallest interval you can set is 30 seconds.

Note: The s, m, and h suffixes specify seconds, minutes, and hours, respectively.