Tag Archive for NAS

Where and why is my data growing?…

I’ve written recently about issues of data gravity and data inertia, and about how important analytics are to managing your data “stockpile”, but one thing I haven’t gone into is the constant challenge of actually understanding your data composition, i.e. what the hell am I actually storing?!

Looking back to my days as a Windows admin maintaining what for the time were some massive, multi-terabyte (ooer – it was 10 years ago to be fair), filers and shared document storage systems; we had little to tell us what the DNA of those file shares was, how much of it was documents and other business-related content, and how much of it was actually people storing their entire MP3 collections and “family photos” on their work shared drives (yes, 100% true!).

Back then our only method of combating these issues was to run TreeSize to see who was using most space, then do windows searches for specific file types and manually clear out the crud; an unenviable task which came across a few surprising finds I won’t go into just now (ooer for the second time)! The problem was that we just didn’t know what we had!

Ten years later I have spoken to customers who are consuming data at very significant rates, but don’t have a grip on where it’s all going…

With that in mind, I was really interested in what the chaps at Qumulo had come up with when they presented at SFD8 recently. As they said at the time, the management of storage is getting easier, but the management of data is getting very much harder! Their primary vision is therefore quite succinctly described as “Build visible data and make storage invisible”.

Their “Data Aware” scale-out NAS solution is based around providing near-realtime analytics on the metadata, and was designed to meet the requirements of the 600 companies and individuals they interviewed before they even came up with their idea!

The product is designed to be software only and subscription-based, though they also provide scale out physical 1u / 4u appliances as well. I guess the main concept there is “have it your way”; there are still plenty of customers out there who want to buy software solution which is pre-qualified and supported on specific hardware (which sounds like an oxymoron but each to their own I say)! Most of Qumulo’s customers today actually buy the appliances.

The coolest thing about their solution is definitely their unique file system (QSFS – Qumulo Scalable File System). It uses a very clever, proprietary method to track changes within the filesystem based on the aggregate of child attributes in the tree (see their SFD8 presentation for more info). As you then don’t need to necessarily walk the entire tree to get an answer to a query (it should be noted this would be one specifically catered for by Qumulo though). It can then present statistics based on those attributes in near-realtime.

Whiteboard Dude approves!

Whiteboard Dude approves!

I would have killed for this level and speed of insight back in my admin days, and frankly I have a few customers right now who would really benefit!

Taking this a step further, the analytics can also provide performance statistics based on file path and type, so for example it could show you where the hotspots are in your filesystem, and which clients are generating them.

Who's using my storage?

Who’s using my storage?

Stuff I would like to see in future versions (though I know they don’t chase the Service Provider market), would be things like the ability to present storage to more than one Active Directory domain, straight forward RBAC (Role Based Access Control) at the management layer, more of the standard data services you see from most vendors (the RFP tick box features). Being able to mix and match the physical appliance types would also be useful as you scale and your requirements change over time, but I guess if you need flexibility, go with the software-only solution.

At a non-feature level, it would be sensible if they could rename their aggregate terminology as I think it just confuses people (aggregates typically mean something else to most storage bods).

Capacity Visualisation

Capacity Visualisation

Overall though I think the Qumulo system is impressive, as are the founder’s credentials. Their CEO/CTO team of Peter Godman and Aaron Passey, with whom we had a good chinwag outside of the SFD8 arena, both played a big part in building the Isilon storage system. As an organisation they already regularly work with customers with over 10 billion files today and up to 4PB of storage.

If their system is capable of handling this kind of scalability having only come out of stealth 8 months ago, they’re definitely one to watch…

Further Reading
Some of the other SFD8 delegates have their own takes on the presentation we saw. Check them out here:

Dan Frith – Qumulo – Storage for people who care about their data

Scott D. Lowe – Data Awareness Is Increasingly Popular in the Storage Biz

Disclaimer/Disclosure: My flights, accommodation, meals, etc, at Storage Field Day 8 were provided by Tech Field Day, but there was no expectation or request for me to write about any of the vendors products or services and I was not compensated in any way for my time at the event.

 

Cannot See Any iSCSI Devices on Synology from a vSphere Host

Just a quick fix I discovered this weekend. It’s probably quite specific but hopefully if you come across this in future it will save you some time.

I had just finished rebuilding the second node in my lab from 5.1 with a fresh install. I added the software iSCSI initiator and connected it to my iSCSI target (Synology DS412+) using Dynamic Discovery. I then rescanned for a list of devices, and although I was picking up the IQN for the iSCSI server, I couldn’t see any devices!

I tried lots of things including removing and re-adding the initiator, messing with iSCSI bindings, but nothing! Very frustrating.

After a bit of googlage, I came across this KB article from VMware:

Cannot see some or all storage devices in VMware vCenter Server or VirtualCenter (1016222)

Although this was specific to VI3/vSphere 4, it did trigger a thought! Just before I built the new node, I rejigged all of my storage LUNs, deleting 3 old ones in the process (which just so happened to be the first 3 LUNs on my NAS). What I believe this caused is that the LUNs were viewed by node 1 as different LUN IDs on node 2, so they refused to show up!

So now, the fix. Incredibly simple as it turns out:

  1. Created three new temp 10GB LUNs on my old NAS which would then assume LUN IDs 1/2/3 as they originally had (before I deleted them).
  2. Rescan the new node of the cluster for storage
  3. Confirmed all of the LUNs are now visible
  4. Deleted the three temp LUNs from the Synology (I don’t plan to add any more nodes for now so I have no need of these temp LUNs, but as they’re thin provisioned anyway it actually wouldn’t hurt to leave them there).
  5. Rescan the ESXi host again to ensure it can still see the LUNs.
  6. Job done!

Synology iSCSI Devices

Not much to it, but worth a quick post I thought as this simple issue wasted a chunk of my time!

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