I have been asked to provide a new fileserver to store our medical images (raw format, not dicom). As we have no IT staff, I have to find a solution, and I hardly know anything about this topic.

The requirements we have are: scalable to 24 TB in 3 years, windows file sharing and the share has to be as big as possible (1x24TB share). First thing I found is the NETGEAR ReadyNAS 3200. Seems like a very good system, accompanied by a big community, which could come in handy if we run into trouble.

But how scalable is this system? Everywhere I'm told that this system is 'not stackable'. I don't know how stacking NAS' work, but maybe we could buy an iSCSI initiator, configure all NAS' as iSCSI targets, then build a raid on the initiator covering all targets, then share this big raid as one windows share? Or can't this be done? I'm clearly at a loss on how scalability works, so if anyone could explain this, I'd be very grateful.

If anyone sees another solution (like another NAS comparable to the readynas'specs but stackable), you can suggest this too of course.


Stackable means that there is a method to connect more disks to the same NAS controller, usually via SAS or something like that, so you can increase the capacity of the same device.

While the Netgear will be available with a 12x2TB (24GB) configuration shortly, according to their website, I don't think that this system will fit your needs, as you will be left with far less storage when configured properly. Depending on your safety requirement, the capacity of one to three disks will be lost (RAID5 means 1 disk lost, the recommended RAID 6 means 2 are gone and if you use a hotspare, you have only 18TB left).

If you are willing to build a file server 'head' anyway, as suggested with your iSCSI RAID idea, one possible solution would be to either buy a server with 24 or even 48 drive bays and install either Win Server or some Linux variant or a more common 1U pizza box server and a RAID box connected via either iSCSI, SAS or Fibre Channel. This RAID boxes, i.e. from Infortrend, are usually stackable, so you can extend the storage afterwards.

BTW, building a RAID from "cheapish" NAS class iSCSI targets is nothing I would recommend, as your whole raid will be lost if you lose the connection to one of the NAS boxes.

If you are not short on budget, you might consider devices like the NetApp FAS2000 series, which are scalable up to more than 100TB, but still offer CIFS file server functions.

What I really would recommend though is looking for a company specializing in storage applications, which often sell many brands and can advise you on what is best for your specific environment, including the all important backup scenarios ( which is really important to do right).


The Sun x4540 will support the storage size you need and ZFS makes it easy to share via CIFS for your Windows machines or you can export the storage over iSCSI. However, as other have mentioned, you should really have a plan for backups and redundancy. Since you don't have any IT staff a vendor who will set everything up for you is probably a good choice.


Normally I'd recommend a NetApp 3100-series for something like this, they're fast, easy to setup/use and pretty resilient but they have a hard-limit of 16TB per presented volume. If seeing this 24TB storage as a single volume is really important then perhaps you could use an HP EVA FC SAN box combined with Veritas Storage Foundation for Windows - that will allow you to see a single volume of up to 32TB. You should know that FC SANs are usually a lot more complex to setup and manage than NAS boxes.


I just installed an Isilon clustered NAS. Started with 24 tera useable on a few nodes & can scale up to over a peta by just plugging in additional nodes. The nice thing is each node added gives both additional storage & throughput, as each node acts as a head node to the clustered. All in a single large filesystem

  • Its important to note that Isilon is a particularly expensive solution to this problem, especially when dealing with a large amount of storage, there are much cheaper alternatives now although less "plug and play"
    – MattyB
    Nov 3 '09 at 16:53

Sun Storage 7000 Unified Storage Systems

  • ZFS: 1x 24TB share is no problem
  • end-to-end checksumming
  • ARC (Adaptive Replacement Cache), Hybrid Strage pool / SSD support for read and write cache
  • snapshots / clones
  • NFS4 / CIFS
  • nice Web interface with "Analytics" analyzer module
  • RAIDZ2 (soon RAIDZ3), RAID1, redundancy modes
  • Infiniband interconnect support; iSCSI
  • all licenses included
  • soon: deduplication

Depending on your OS/hardware you may have issues with arrays over 2TB. There are products which are fine with larger but it requires some research to avoid the problem.


You should be looking at something "enterprise" grade, or at the very least cheap enough to build a redundant online disk solution. Storing the data is only part of the problem, it needs to be redundant, be easily recoverable, and be built on a system that allows for the inevitable failure of disks, corruption etc. I would look at using the SATABeast http://www.nexsan.com/satabeast.php as a high density storage solution. It supports fibre and iscsi connections to a backend server, and then use either a Solaris server running ZFS for the actual data storage on that array or a Linux server running XFS / LVM.

You didn't speak much to price range, but in the case of large storage you get what you pay for, and if the data is important than you should do what you can to ensure that it is safe. If you don't have IT staff you should contract someone to build this for you, because again if it fails and the data is important and its not an open solution built well you will be in for a lot of pain. As the poster above mentioned if you are in the 35k+ range for a solution than Netapp may be applicable as a vendor, very easy to work with but expensive gear.


I recommend having a look at: www.scalableinformatics.com

and their JackRabbit and Delta-V products.


If you know nothing about the topic, and don't have in-house access to people who have such knowledge, you need to go elsewhere. If you have alot of money, find an EMC reseller and buy a lower-end NAS appliance with remote management services.

If you don't have alot of money, find a small business computer consulting place that can build and support a solution for you.

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