How to build an iSCSI SAN

[DannoSV]

Hi,

I'm new to SAN's and storage but have been reading up on them. I would like to build an iSCSI SAN as that seems to be the leaset expensive way to do it. If someone disagree's, please let me know. (EqualLogic's start at $20K - $40K per their Sales Rep. for 2 - 3 TB's)

My understanding is that the iSCSI SAN consists of the iSCSI target (or the storage), a Gigabit switch (recommended) and the SAN Hosts (or servers that will connect to the iSCSI target). And of course there are the decisions of whether to use HBA's or TOE's or just Gigabith NIC's for which I'm aware of but not too educated on just yet.

My confusion is with the iSCSI target. How do I build this? Looking at examples of iSCSI targets I see a 2 or 3 U unit that consists of a row of disks. Where do I find this enclosure? Am I barking up the wrong tree?

Once I figure this out, I believe there is then software that is required for the SAN to function. Is this right?

Your help is appreciated. I'm trying to learn all there is to know about this so I set it up properly.

 

[comtec17]

First, you will not use HBA's for iSCSI storage. You will either use your existing NIC or a TOE.

The iSCSI target is the Disk you want to present to the host. This target is made from a disk array you have allocated as the central storage point (tier 1 storage).

These enclosures are sold by the vendor.

iSCSI is just SCSI running over your IP infrastructure with your host being an initiator and the disk being a target. This is not CIFS or NFS, these are actual Logical Units of disk.

 

[DannoSV]

thanks for the clarification on the HBA's.

I'll be using this SAN for archiving messaging data so will probably use mid-range or tier2 storage. Just determined this from looking up tier1 storage.

I'm still wondering if I can buy a white-box enclosure for the array and build it myself or if I have to purchase this from a vendor.

 

[WhiteVolg]

You might look at

http://www.falconstor.com/

I'm currently working with their product, and once we get our HDS problems resolved, It looks like it may be a solid solution.

 

[jmreinwald]

Just to expand the above, your two main choices are iSCSI and FCP. For cost reasons, iSCSI is the way to go since you can leverage the IP framework you've already got established with no need for extra hardware.

Fibre-channel can be quite expensive since you're dealing with specialized hardware (the HBAs), then you have to deal with the cabling and whatnot.

In either case, most (if not all vendors) should support both protocols. If you do decide to expand on down the road to FCP (if you decide to go with iSCSI initially) you can very likely use the same data backend and deal with probably just licenses and the extra hardware.

 

[speculos]

Fibre-channel is expensive but performance is better, I/O are fast and stable;
iSCSI performance will depend on your network infrastructure.