Netapp NS0-155 - Data ONTAP 7-Mode Administrator

http://www.netapp.com/us/system/pdf-reader.aspx?m=tr-3786.pdf &cc=us

http://wafl.co.uk/ndmpcopy/

Because volume SnapMirror works at the block level, the source and destination must both be FlexVol volumes in the same aggregate type. The source and destination of a volume SnapMirror relationship must either both be FlexVol volumes in 32-bit aggregates or both be FlexVol volumes in 64-bit aggregates.

Therefore you cannot create a volume SnapMirror relationship from a FlexVol volume in a 32-bit aggregate to a FlexVol volume in a 64-bit aggregate or vice versa.

https://library.netapp.com/ecmdocs/ECMP1196890/html/man1/na_iscsi.1.html

iscsi security show

Display the default authentication and all the initiator specific authentication information.

Hint: Remember that the iscsi command is mostly structured "iscsi noun verb", unlike the fcp command which is structure "fcp verb noun". Example: iscsi initiator show, fcp show initiator.

http://www.brocade.com/downloads/documents/white_papers/Zoning_Best_Practices_WP-00.pdf

Separating the disk and tape devices into separate zones prevents disk RSCNs from impacting tape devices, which tend to be more sensitive to RSCNs.

Best practice is to zone each initiator WWPN to each target WWPN individually.

https://communities.netapp.com/servlet/JiveServlet/previewBody/4803-102-1-6405/tr-3548.pdf

It is important to remember that this is the case only when a complete site is lost. In the case of a failed controller at one of the sites, a normal cluster failover occurs. Due to the operation of SyncMirror, there is also added protection from multidrive or complete shelf failures. When a storage controller fails in an active-active configuration, the partner detects the failure and automatically (if enabled) performs a takeover of the dataserving responsibilities from the failed controller. Part of this process relies on the surviving controller being able to read information from the disks on the failed controller. If this quorum of disks is not available, then automatic takeover won’t be performed. In a MetroCluster configuration, manually executing a single command will allow a takeover to occur in spite of the lack of a quorum of disks. This "forced takeover" process breaks the mirrored relationships in order to bring the failed controller’s volumes on line.

forcetakeover -d is very dangerous. Not only can it cause data corruption, if not used carefully, it can also lead to a situation where both the node and its partner are operational (split brain). As such, it should only be used as a means of last resort when the takeover and forcetakeover commands are unsuccessful in achieving a takeover. The operator must ensure that the partner node does not become operational at any time while a node is in a takeover mode initiated by the use of this command. In conjunction with RAID mirroring, it can allow recovery from a disaster when the two nodes in the HA pair are located at two distant sites.

You can use the snapmirror resync command to reestablish the connection between the source and the destination. This command is applied after the SnapMirror relationship between the source and destination is broken.

https://library.netapp.com/ecmdocs/ECMP1196991/html/GUID-5D846D24-0903-4982-A429-71AE5C0F9033.html

The rules for the selection of disks or array LUNs, for using as mirrored aggregates, are as follows:

Disks or array LUNs selected for each plex must be in different pools.

The same number of disks or array LUNs must be in both the plexes.

Disks are selected first on the basis of equivalent bytes per sector (bps) size, then on the basis of the size of the disk.

If there is no equivalent-sized disk, Data ONTAP uses a larger-capacity disk, and limits the size to make it identically sized.

Data ONTAP names the plexes of the mirrored aggregate.

https://library.netapp.com/ecmdocs/ECMP1196991/html/GUID-F5F241AF-50C0-4FF3-8C01-96958581C4D9.html

For a detailed breakdown of the procedure see the following KB

https://kb.netapp.com/support/index?page=content &id=1011576