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ChumpusRex

Any I. T. Guys Know Anything About S. A. N.s?

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This is a bit of a long shot, but I'm pretty sure there are some IT contractors here. I've got a couple of questions about SANs, which are hopefully straightforward.

I just want to be clear about a few things and sound intelligent when speaking to some managers at work

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This is a bit of a long shot, but I'm pretty sure there are some IT contractors here. I've got a couple of questions about SANs, which are hopefully straightforward. I just want to be clear about a few things and sound intelligent when speaking to some managers at work

Long gone is right but post or pm me and I will give you some intelligent words for the purpose of sounding professional

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I took out a SAN storage device for one of my servers.

I have a host name, user name and password.

A month on, and with limited time to look at this, I still have absolutely no idea whatsoever how to connect to it.

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SAN is an appliance usually ie, a storage server that isnt a server per se.

Like Cloud, much of the technobollocks is marketing.

simply put, its a hard disk on a network....hence, Storage Area Network.

Suspect any person giving it large with technobollocks.

As seen from this definition of what a SAN could be in an enterprise: lots of techno in this, but all they are saying is this particular application is hard disks on a FAST network between other servers that THEN connect to clients.:

A storage area network (SAN) is a high-speed special-purpose network (or subnetwork) that interconnects different kinds of data storage devices with associated data servers on behalf of a larger network of users.

Typically, a storage area network is part of the overall network of computing resources for an enterprise. A storage area network is usually clustered in close proximity to other computing resources such as IBM z990 mainframes but may also extend to remote locations for backup and archival storage, using wide area network carrier technologies such as ATM or SONET.

A storage area network can use existing communication technology such as IBM's optical fiber ESCON or use Fibre Channel technology. Some SAN system integrators liken it to the common storage bus (flow of data) in a personal computer that is shared by different kinds of storage devices such as a hard disk or a CD-ROM player.

SANs support disk mirroring, backup and restore, archival and retrieval of archived data, data migration from one storage device to another and the sharing of data among different servers in a network. SANs can incorporate subnetworks with network-attached storage (NAS) systems.

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Like Cloud, much of the technobollocks is marketing.

simply put, its a hard disk on a network....hence, Storage Area Network.

Suspect any person giving it large with technobollocks.

Right you, you're not working in sales any more! :blink:;)

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Servers can access network storage via LUNS, which are like gateways to a block of disk space. This space appears as a local hard disk to the host irrespective of it's remote nature.

Typically you don't have multiple devices connected to the same LUN as the same time. In a cluster environment you might have a iscsi connection to the SAN via a lun, and when you failover a cluster node, the failover moves the LUN to the active node. Don't think of it like a file repository or typical cifs share, as access it more exclusive than that, it's more like a network share where an application can put core files it uses that may need to available to another host in a sepcific scenario.

Typical example is a databse server cluster - you might be popping the data file and the log file on different luns and these apper as drive x and z locally to host 1, then you failover your database services to host 2, and the x and z drives move with it. The integrity of the configuration has been maintained across the nodes.

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Servers can access network storage via LUNS, which are like gateways to a block of disk space. This space appears as a local hard disk to the host irrespective of it's remote nature.

Typically you don't have multiple devices connected to the same LUN as the same time. In a cluster environment you might have a iscsi connection to the SAN via a lun, and when you failover a cluster node, the failover moves the LUN to the active node. Don't think of it like a file repository or typical cifs share, as access it more exclusive than that, it's more like a network share where an application can put core files it uses that may need to available to another host in a sepcific scenario.

Typical example is a databse server cluster - you might be popping the data file and the log file on different luns and these apper as drive x and z locally to host 1, then you failover your database services to host 2, and the x and z drives move with it. The integrity of the configuration has been maintained across the nodes.

Well that totally lost me! Anyone else?

I just see a disk drive on my network! :huh:

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This is a bit of a long shot, but I'm pretty sure there are some IT contractors here. I've got a couple of questions about SANs, which are hopefully straightforward.

I just want to be clear about a few things and sound intelligent when speaking to some managers at work

Easy just through in a lot of meaningless jargon.

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This is a bit of a long shot, but I'm pretty sure there are some IT contractors here. I've got a couple of questions about SANs, which are hopefully straightforward.

I just want to be clear about a few things and sound intelligent when speaking to some managers at work

Whilst the term generarlly was used to refer to Fibrechannel SANs, I have also seen it used to described iSCSI and this seem more prevelant now we have 10G Ethernet and hence 10Ge iSCSI, especially as many storage arrays have interchangeable Fiberchannel/iSCSI ports.

The current top level Fiberchannel speed is 16Gb/s, having recently moved up from 8, but most Fiberchannel adapters/interfaces will clock down to support legacy technology.

Fiberchannel connections can be made directly between a storage array and a server with a Fiberchannel Adapter, or alternatively through either a Fiberchannel Switch or an even bigger Fiberchannel Switch which with more ports which people sometime call a Director - this effectively giving you a storage network.

There are also some very cool SAN appliances out there, that can do clever thing like move Hot Data Blocks around between different disk tiers (I know IBM SVC quite well). Typically Flash Solid State Disks might be used for the fastest read operation, whilst SAS 10/15K drives might be used for larger capacity pools that still need good IOP (Input Outputs per second) performance, whilst Nearline SAS or SATA with the slower 7.2K spindles might be used as a cheaper tier or perhaps for sequential workload (these disks are good for sequential as the 3.5 inch variants actually have larger platter than most SAS drives which are tending to 2.5" and consequently they can cover more surface area on each rotation - but the actuators are less able which is why their random is poor).

In terms of vendors, you could typically look at people like EMC, NetApp and HDS as dedicated storage companies with a SAN proposition. Firms like HP also have products that can be considered enterprise, though I'd perhaps avoid IBM now as I am not sure where their hardware business is really going, though there SVC easy tiering is good, but you might be better putting someone else disk behind it.

As mentioned above, blocks of storage are accessed via LUNs, which stands for Logical Unit Number, a terms left over from the early days of SCSI when SCSI disks had a number in the chain. So typically you'd present a LUN to a server to use. The term volume can also be used, though a volume might exist on a disk array and could be carved up into LUNs, so actually what a volume is really depends on you perspective, as a LUN presented to a server could also be carved up into separate volumes.

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Well that totally lost me! Anyone else?

I just see a disk drive on my network! :huh:

what he is saying is what you are presented with on the lan is a standard hdd to you , these are lun`s logical drive`s or volumes in the background.

clustering is creating redundancy i.e physical failure results in a seem less cut over to a mirrored system.

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As mentioned above, blocks of storage are accessed via LUNs, which stands for Logical Unit Number, a terms left over from the early days of SCSI when SCSI disks had a number in the chain. So typically you'd present a LUN to a server to use. The term volume can also be used, though a volume might exist on a disk array and could be carved up into LUNs, so actually what a volume is really depends on you perspective, as a LUN presented to a server could also be carved up into separate volumes.

in other words, as far as the practicality is concerned, its a hard drive on a network.

People dont know how the OS works, why should they need to know about LUNS, failover and redundancy?

People go all gooey over Servers....when in reality, the server is like the waiter in a restaurant, dishing out the orders from the chef...the user, who happens to be the chef and the client.

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in other words, as far as the practicality is concerned, its a hard drive on a network.

Remember to beware the consultant who cannot explain simple concepts in simple terms.

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Remember to beware the consultant who cannot explain simple concepts in simple terms.

Beware the "consultant" employed by your boss, who doesn't know as much as you do!

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Well that totally lost me! Anyone else?

I just see a disk drive on my network! :huh:

I lost the ability to b***shit when spigots, flanges, trunnions, grommets and gimbals went out of fashion!

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