EMC Storage Product Knowledge Sharing

We have discuss about Fibre Technology in brief in earlier post. We will be discussing about FC Port Addressing and Fabric Ports. There are certain rules for Port addressing and different ports used for it. Lets summarise point for each in breif.FC Port Addressing:FC uses a 3 Byte address identifier. Dynamically assigned during the LOGIN process.Reserved well known addresses used for Fabric, Alias Server, or the Multicast Server - hex'FFFFF0' to hex'FFFFFE'. hex'FFFFFF' is the Broadcast address. Arbitrated Loop addresses are...

Lets discuss about LUNz/LUN_Z in Operating System specially in CLARiiON environment. We know that what is LUN?? LUN is nothing but logical slice of disc which stands for Logical Unit Number. This terminology comes with SCSI-3 group, if you want to know more just visit www.t10.org and www.t11.orgA SCSI-3 (SCC-2) term defined as "the logical unit number that an application client uses to communicate with, configure and determine information about an SCSI storage array and the logical units attached to it. The LUN_Z value shall...

Lets discuss about most important thing in SAN environment ZONING. Zoning is the only way to restrict access for storage to all the host. We will be discussing about Zoning in details.There are two type of Zoning basically : Hard Zoning and Soft Zoning. Lets first define what is Zoning??Zoning is nothing but map of host to device to device connectivity is overlaid on the storage networking fabric, reducing the risk of unauthorized access.Zoning supports the grouping of hosts, switches, and storage on the SAN, limiting access...

I have been receiving mail to write on basic storage topic rather than only EMC. Here is first basic thing to know about FC technology.Fibare Channel is nothing but just a medium to connect host and shared storage. When we talk about SAN first things comes in mind about Fibre Channel.Fibre Channel is serial data transfer interface intended for connecting shared storage to computer. Where storage is not connected physically to host.Why FC is most important in SAN? Because FC gives you high speed through the following process:1)...

When running inq or syminq, you'll see a column titled Ser Num. This column has quite a bit of information hiding in it. An example syminq output is below. Your output will differ slightly as I'm creating a table from a book to show this; I don't currently have access to a system where I can get the actual output just yet.Device Product Device ------------------------ ---------- ---------------------- ----------------------...

SYMCLI BASE Commandssymapierr - Used to translate SYMAPI error code numbers into SYMAPI error messages.symaudit - List records from a symmetrix audit log file.symbcv - Perform BCV support operations on Symmetrix BCV devices.symcfg - Discover or display Symmetrix configuration information. Refresh the host's Symmetrix database file or remove Symmetrix info from the file. Can also be used to view or release a 'hanging' Symmetrix exclusive lock.symchg ...

MDS Interoperability Mode Limitations When a VSAN is configured for the default interoperability mode, the MDS 9000 Family of switches is limited in the following areas when interoperating with non-MDS switches: • Interop mode only affects the specified VSAN. The MDS 9000 switch can still operate with full functionality in other non-interop mode VSANs. All switches that partake in the interoperable VSAN should have that VSAN set to interop mode, even if they do not have...

What are the CLARiiON SAN fan-in and fan-out configuration rules?"Fan-In Rule: A server can be zoned to a maximum of four storage systems. Fan-Out Rule: For FC5300 with Access Logix software - 1 - 4 servers (eight initiators) to 1 storage system. For FC4500 with Access Logix - 15 servers to 1 storage system; each server with a maximum of one (single) path to an SP. For FC4700 with Base or Access Logix software 8.42.xx or higher - 32 initiators per SP port for a maximum of 128 initiators per FC4700....

Save Set Staging: Save set staging is a process of transferring data from one storage medium to another. Staging reduces the time it takes to complete a backup by directing the initial backup to a high performance file type or adv_file device. The data can then be staged to a storage medium, freeing up the disk space. Any volume type, such as Default, Index Archive, or Default Clone, can be staged. Staging is particularly well suited for data that has been backed up on file type or adv_file devices....

There is available WWN decoder tool for EMC but I am going to discuss how to decode manually?Each Symmetrix SAF port, RAF port, EF ficon port or DAF port (DMX only) has a unique worldwide name (WWN). The WWN is associated with the Tachyon chip on the director. It was intended to remain unique per director so that the director can be accessed on a storage area network. The Symmetrix SAF/RAF/DAF/EF WWN is dependent on the Symmetrix serial number, the director number, the processor letter, and the port on the processor. When...

Generally we never give thought about VCMDB database once we initialize first time. It does make sense when you messup or did some thing disaster. This database is most impppppportaaaaaaant for DMX. Once you loose this database means you can't get DMX configuration back at any cost. So, I am discussing different type of VCMDB on DMX.We can now support up to 16,000/64000 addressable devices enginuity 5771 onward and therefore the Volume Control Manager Database needs to be physically larger. At 5670, as per EMC recommend CE's...

I am going to discuss about TimeFinder BCV Split operation where Host running on Oracle Database. This split operation is different from normal BCV split operation. There are differences in command as well. Thats reason I am putting steps for this:The following steps describes splitting BCV devices that hold a database supporting a host running an Oracle database. In this case, the BCV split operation is in an environment without PowerPath or ECA. The split operation described here suspends writes to a database momentarily while...

Vendor Worldwide Names WWN :Twenty-four of the sixty-four bit •World Wide Name• must be unique for every vendor. A partial listing of those vendors most familiar to EMC with regard to Symmetrix Fibre Channel connectivity.If decoding a HBA WWN, then issue an 8f, command to view the WWN in the FA login table. Bytes 1-3 of the World Wide Names contain the unique vender codes. Note that if there is a switch connected between the FA and the host bus adapter, then the name and fabric servers of the switch will login to the FA. These...

Brocade Switches:How to merge two switches with different active zone sets."Merging Two B-series Directors and/or Switches with Different Active Zoning ConfigurationsBefore Beginning The following procedure is disruptive to fabric traffic.:--It will require disabling the switch and the removal of the effective zoning configurations at one step. Removing this configuration will stop the data flow. Since this step in the procedure takes only a few moments to complete, data should resume as soon as the new configuration is activated.To...

There are different type of SAN like IP SAN, NAS over SAN etc... We will discuss about Fibre Channel SAN. It gives you more option in order to manage and minimize downtime means reducing company cost.In general if you think storage environments, physical interfaces to storage consisted of parallel SCSI channels supporting a small number of SCSI devices. With Fibre Channel, the technology provides a means to implement robust storage area...

Lets first disuss what is Powerpath software. If you are familiar with EMC product and then definitelly will be using EMC Powerpath software. Those who are new to storage world, it will interesting to know about this product as there are only few software in this category like DMP,PVLINK, LVM etc from other vendor. This sofware is one of the most robust compare to other, thats reason EMC generationg more revenue out of this Product.......

What are the differences between failover modes on a CLARiiON array?A CLARiiON array is an Active/Passive device and uses a LUN ownership model. In other words, when a LUN is bound it has a default owner, either SP-A or SP-B. I/O requests traveling to a port SP-A can only reach LUNs owned by SP-A and I/O requests traveling to a port on SP-B can only reach LUNs owned SP-B. It is necessary to have different failover methods because in certain situations a host will need to access a LUN on the non-owning SP.The following failover...

DMP With CLARiiON:-CLARiiON arrays are active-passive devices that allow only one path at a time to be used for I/O. The path that is used for I/O is called the active or primary path. An alternate path (or secondary path) is configured for use in the event that the primary path fails. If the primary path to the array is lost, DMP automatically routes I/O over the secondary path or other available primary paths.For active/passive disk arrays, VxVM uses the available primary path as long as it is accessible. DMP shifts I/O to...