StorageIO Momentus Hybrid Hard Disk Drive (HHDD) Moments

This is the third in a series of posts that I have done about Hybrid Hard Disk Drives (HHDDs) along with pieces about Hard Disk Drives (HDD) and Solid State Devices (SSDs). Granted the HDD received its AARP card several years ago when it turned 50 and is routinely declared dead (or read here) even though it continues to evolve along SSD maturing and both expanding into different markets as well as usage roles.

For those who have not read previous posts about Hybrid Hard Disk Drives (HHDDs) and the Seagate Momentus XT you can find them here and here.

Since my last post, I have been using the HHDDs extensively and recently installed the latest firmware. The release of new HHDD firmware by Seagate for the Momentus XT (SD 25) like its predecessor SD24 cleaned up some annoyances and improved on overall stability. Here is a Seagate post by Mark Wojtasiak discussing SD25 and feedback obtained via the Momentus XT forum from customers.

If you have never done a HDD firmware update, its not as bad or intimidating as might be expected. The Seagate firmware update tools make it very easy, that is assuming you have a recent good backup of your data (one that can be restored) and about 10 to 15 minutes of time for a couple of reboots.

Speaking of stability, the Momentus XT HHDDs have been performing well helping to speed up accessing large documents on various projects including those for my new book. Granted an SSD would be faster across the board, however the large capacity at the price point of the HHDD is what makes it a hybrid value proposition. As I have said in previous posts, if you have the need for speed all of the time and time is money, get an SSD. Likewise if you need as much capacity as you can get and performance is not your primary objective, then leverage the high capacity HDDs. On the other hand, if you need a balance of some performance boost with capacity boost and a good value, then check out the HHDDs.

Image of Momentus XT courtesy of www.Seagate.com

Lets shift gears from that of the product or technology to that of common questions that I get asked about HHDDs.

Common questions I get asked about HHDDs include:

What is a Hybrid Hard Disk Drive?

A Hybrid Hard Disk Drive includes a combination of rotating HDD, solid state flash persistent memory along with volatile dynamic random access memory (DRAM) in an integrated package or product. The value proposition and benefit is a balance of performance and capacity at a good price for those environments, systems or applications that do not need all SSD performance (and cost) vs. those that need some performance in addition to large capacity.

How the Seagate Momentus XT differs from other Hybrid Disks?
One approach is to take a traditional HDD and pair it with a SSD using a controller packaged in various ways. For example on a large scale, HDDs and SSDs coexist in the same tiered storage system being managed by the controllers, storage processors or nodes in the solution including automated tiering and cache promotion or demotion. The main difference however between other storage systems, tiering and pairing and HHDDs is that in the case of the Momentus XT the HDD, SLC flash (SSD functionality) and RAM cache and their management are all integrated within the disk drive enclosure.

Do I use SSDs and HDDs or just HHDDs?
I have HHDDs installed internally in my laptops. I also have HDDs which are installed in servers, NAS and disk to disk (D2D) backup devices and Digital Video Recorders (DVRs) along with external SSD and Removable Hard Disk Drives (RHDDs). The RHDDs are used for archive and master or gold copy data protection that go offsite complimenting how I also use cloud backup services as part of my data protection strategy.

What are the technical specifications of a HHDD such as the Seagate Momentus XT?
3Gbs SATA interface, 2.5 inch 500GB 7,200 RPM HDD with 32MB RAM cache and integrated 4GByte SLC flash all managed via internal drive processor. Power consumption varies depending what the device is doing such as initial power up, idle, normal or other operating modes. You can view the Seagate Momentus XT 500GB (ST95005620AS which is what I have) specifications here as well as the product manual here.


One of my HHDDs on a note pad (paper) and other accessories

Do you need a special controller or management software?
Generally speaking no, the HHDD that I have been using plugged and played into my existing laptops internal bay replacing the HDD that came with those systems. No extra software was needed for Windows, no data movement or migration tools needed other than when initially copying from the source HDD to the new HHDD. The HHDD do their own caching, read ahead and write behind independent of the operating system or controller. Now the reason I say generally speaking is that like many devices, some operating systems or controllers may be able to leverage advanced features so check your particular system capabilities.

How come the storage system vendors are not talking about these HHDDs?
Good question which I assume it has a lot to do with the investment (people, time, engineering, money and marketing) that they have or are making in controller and storage system software functionality to effectively create hybrid tiered storage systems using SSD and HDDs on different scales. There have been some packaged HHDD systems or solutions brought to market by different vendors that combine HDD and SSD into a single physical package glued together with some software and controllers or processors to appear as a single system. I would not be surprised to see discrete HHDDs (where the HDD and flash SSD and RAM are all one integrated product) appear in lower end NAS or multifunction storage systems as well as for backup, dedupe or other system that requires large amounts of capacity space and performance boost now and then.

Why do I think this? Simple, say you have five HHDDs each with 500GB of capacity configured as a RAID5 set resulting in 2TByte of capacity. Using as a hypothetical example the Momentus XT yields 5 x 4GByte or 20GByte of flash cache helps accelerate write operations during data dumps, backup or other updates. Granted that is an overly simplified example and storage systems can be found with hundreds of GByte of cache, however think in terms of value or low cost balancing performance and capacity to cost for different usage scenarios. For example, applications such as bulk or scale out file and object storage including cloud or big data, entertainment, Server (Citrix/Xen, Microsoft/HyperV, VMware/vSphere) and Desktop virtualization or VDI, Disk to Disk (D2D) backup, business analytics among others. The common tenets of those applications and usage scenario is a combination of I/O and storage consolidation in a cost effective manner addressing the continuing storage capacity to I/O performance gap.

Data Center and I/O Bottlenecks

Storage and I/O performance gap

Do you have to backup HHDDs?
Yes, just as you would want to backup or protect any SSD or HHD device or system.

How does data get moved between the SSD and the HDD?
Other than the initial data migration from the old HDD (or SSD) to the HHDD, unless you are starting with a new system, once your data and applications exist on the HHDD, it automatically via the internal process of the device manages the RAM, flash and HDD activity. Unlike in a tiered storage system where data blocks or files may be moved between different types of storage devices, inside the HHDD, all data gets written to the HDD, however the flash and RAM are used as buffers for caching depending on activity needs. If you have sat through or listened to a NetApp or HDS use of cache for tiering discussion what the HHDDs do is similar in concept however on a smaller scale at the device level, potentially even in a complimentary mode in the future? Other functions performed inside the HHDD by its processor includes reading and writing, managing the caches, bad block replacement or re vectoring on the HDD, wear leveling of the SLC flash and other routine tasks such as integrity checks and diagnostics. Unlike paired storage solutions where data gets moved between tiers or types of devices, once data is stored in the HHDD, it is managed by the device similar to how a SSD or HDD would move blocks of data to and from the specific media along with leveraging RAM cache as a buffer.

Where is the controller that manages the SSD and HDD?
The HHDD itself is the controller per say in that the internal processor that manages the HDD also directly access the RAM and flash.

What type of flash is used and will it wear out?
The XT uses SLC (single level cell) flash which with wear leveling has a good duty cycle (life span) and is what is typically found in higher end flash SSD solutions vs. lower cost MLC (multi level cell)

Have I lost any data from it yet?
No, at least nothing that was not my own fault from saving the wrong file in the wrong place and having to recover from one of my recent D2D copies or the cloud. Oh, regarding what have I done with the HDDs that were replaced by the HHDDs? They are now an extra gold master backup copy as of a particular point in time and are being kept in a safe secure facility, encrypted of course.

Have you noticed a performance improvement?
Yes, performance will vary however in many cases I have seen performance comparable to SSD on both reads and writes as long as the HDDs keep up with the flash and RAM cache. Even as larger amounts of data are written, I have seen better performance than compared to HDDs. The caveat however is that initially you may see little to marginal performance improvement however over time, particularly on the same files, performance tends to improve. Working on large tens to hundreds of MByte size documents I noticed good performance when doing saves compared to working with them on a HDD.

What do the HHDDs cost?
Amazon.com has the 500GB model for about $100 which is about $40 to $50 less than when I bought my most recent one last fall. I have heard from other people that you can find them at even lower prices at other venues. In the theme of disclosures, I bought one of my HHDDs from Amazon and Seagate gave me one to test.

Will I buy more HHDDs or switch to SSDs?
Where applicable I will add SSDs as well as HDDs, however where possible and practical, I will also add HHDDs perhaps even replacing the HDDs in my NAS system with HHDDs at some time or maybe trying them in a DVR.

What is the down side to the HHDDs?
Im generating and saving more data on the devices at a faster rate which means that when I installed them I was wondering if I would ever fill up a 500GB drive. I still have hundreds of GBytes free or available for use, however I also am able to cary more reference data or information than in the past. In addition to more reference data including videos, audio, images, slide decks and other content, I have also been able to keep more versions or copies of documents which has been handy on the book project. Data that changes gets backed up D2D as well as to my cloud provider including while traveling. Leveraging compression and dedupe, given that many chapters or other content are similar, not as much data actually gets transmitted when doing cloud backups which has been handy when doing a backup from a airplane flying over the clouds. A wish for the XT type of HHDD that I have is for vendors such as Seagate to add Self Encrypting Disk (SED) capabilities to them along with applying continued intelligent power management (IPM) enhancements.

Why do I like the HHDD?
Simple, it solves both business and technology challenges while being an enabler, it gives me a balance of performance for productivity and capacity in a cost effective manner while being transparent to the systems it works with.

Here are some related links to additional material:
Data Center I/O Bottlenecks Performance Issues and Impacts
Has SSD put Hard Disk Drives (HDDs) On Endangered Species List?
Seagate Momentus XT SD 25 firmware
Seagate Momentus XT SD25 firmware update coming this week
A Storage I/O Momentus Moment
Another StorageIO Hybrid Momentus Moment
As the Hard Disk Drive (HDD) continues to spin
Has SSD put Hard Disk Drives (HDDs) On Endangered Species List?
Funeral for a Friend
As the Hard Disk Drive (HDD) continues to spin
Seagate Momentus XT product specifications
Seagate Momentus XT product manual
Technology Tiering, Servers Storage and Snow Removal
Self Encrypting Disks (SEDs)

Ok, nuff said for now

Cheers Gs

Greg Schulz – Author The Green and Virtual Data Center (CRC), Resilient Storage Networks (Elsevier) and coming summer 2011 Cloud and Virtual Data Storage Networking (CRC)
twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2011 StorageIO and UnlimitedIO All Rights Reserved

As the Hard Disk Drive HDD continues to spin

As the Hard Disk Drive HDD continues to spin

server storage data infrastructure i/o iop hdd ssd trends

Updated 2/10/2018

Despite having been repeatedly declared dead at the hands of some new emerging technology over the past several decades, the Hard Disk Drive (HDD) continues to spin and evolve as it moves towards its 60th birthday.

More recently HDDs have been declared dead due to flash SSD that according to some predictions, should have caused the HDD to be extinct by now.

Meanwhile, having not yet died in addition to having qualified for its AARP membership a few years ago, the HDD continues to evolve in capacity, smaller form factor, performance, reliability, density along with cost improvements.

Back in 2006 I did an article titled Happy 50th, hard drive, but will you make it to 60?

IMHO it is safe to say that the HDD will be around for at least a few more years if not another decade (or more).

This is not to say that the HDD has outlived its usefulness or that there are not other tiered storage mediums to do specific jobs or tasks better (there are).

Instead, the HDD continues to evolve and is complimented by flash SSD in a way that HDDs are complimenting magnetic tape (another declared dead technology) each finding new roles to support more data being stored for longer periods of time.

After all, there is no such thing as a data or information recession!

What the importance of this is about technology tiering and resource alignment, matching the applicable technology to the task at hand.

Technology tiering (Servers, storage, networking, snow removal) is about aligning the applicable resource that is best suited to a particular need in a cost as well as productive manner. The HDD remains a viable tiered storage medium that continues to evolve while taking on new roles coexisting with SSD and tape along with cloud resources. These and other technologies have their place which ideally is finding or expanding into new markets instead of simply trying to cannibalize each other for market share.

Here is a link to a good story by Lucas Mearian on the history or evolution of the hard disk drive (HDD) including how a 1TB device that costs about $60 today would have cost about a trillion dollars back in the 1950s. FWIW, IMHO the 1 trillion dollars is low and should be more around 2 to 5 trillion for the one TByte if you apply common costs for management, people, care and feeding, power, cooling, backup, BC, DR and other functions.

Where To Learn More

View additional NAS, NVMe, SSD, NVM, SCM, Data Infrastructure and HDD related topics via the following links.

Additional learning experiences along with common questions (and answers), as well as tips can be found in Software Defined Data Infrastructure Essentials book.

Software Defined Data Infrastructure Essentials Book SDDC

What This All Means

IMHO, it is safe to say that the HDD is here to stay for at least a few more years (if not decades) or at least until someone decides to try a new creative marketing approach by declaring it dead (again).

Ok, nuff said, for now.

Gs

Greg Schulz – Microsoft MVP Cloud and Data Center Management, VMware vExpert 2010-2017 (vSAN and vCloud). Author of Software Defined Data Infrastructure Essentials (CRC Press), as well as Cloud and Virtual Data Storage Networking (CRC Press), The Green and Virtual Data Center (CRC Press), Resilient Storage Networks (Elsevier) and twitter @storageio. Courteous comments are welcome for consideration. First published on https://storageioblog.com any reproduction in whole, in part, with changes to content, without source attribution under title or without permission is forbidden.

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2024 Server StorageIO and UnlimitedIO. All Rights Reserved. StorageIO is a registered Trade Mark (TM) of Server StorageIO.

Another StorageIO Hybrid Momentus Moment

Its been a few months since my last post (read it here) about Hybrid Hard Disk Drive (HHDD) such as the Seagate Momentus XT that I have been using.

The Momentus XT HHDD I have been using is a 500GB 7,200RPM 2.5 inch SATA Hard Disk Drive (HDD) with 4GB of embedded FLASH (aka SSD) and 32MB of DRAM memory for buffering hence the hybrid name.

I have been using the XT HHDD mainly for transferring large multi GByte size files between computers and for doing some disk to disk (D2D) backups while becoming more comfortable with it. While not as fast as my 64GB all flash SSD, the XT HHDD is as fast as my 7,200RPM 160GB Momentus HDD and in some cases faster on burst reads or writes. The notion of having a 500GB HDD that was affordable to support D2D was attractive however the ability to get some performance boost now and then via the embedded 4GB FLASH opens many different possibilities particularly when combined with compression.

Recently I switched the role of the Momentus XT HHDD from that of being a utility drive to becoming the main disk in one of my laptops. Despite many forums or bulletin boards touting issues or problems with the Seagate Momentus XT causing system hangs or Windows Blue Screen of Death (BSoD), I continued on with the next phase of testing.

Making the switch to XT HHDD as a primary disk

I took a few precaution including eating some of my own dog food that I routinely talk about. For example, I made sure that the Lenovo T61 where the Momentus XT was going to be installed was backed up. In addition, I synced my traveling laptop so that it was the primary so that I could continue working during the conversion not to mention having an extra copy in addition to normal on and offsite backups.

Ok, lets get back to the conversion or migration from a regular HDD to the HHDD.

Once I knew I had a good backup, I used the Seagate Discwizard (e.g. Acronis based) tool for imaging the existing T61 HDD to the Momentus XT HHDD. Using Discwizard (you could use other tools as well) I configured it to initialize the HHDD which was attached via a Seagate Goflex USB to SATA cable kit as well as image or copy the contents of the T61 HDD partitions to the Momentus XT. During the several hours it took to copy and create a new bootable disk image on the HHDD I continued working on my travel or standby laptop.

After the image copy was completed and verified, it was time to reboot and see how Windows (XP SP3) liked the HHDD which all seemed to be normal. There were some parts of the boot that seemed a bit faster, however not 100 percent conclusive. The next step was to shutdown the laptop and physically swap the old internal HDD with the HHDD and reboot. The subsequent boot did seem faster and programs accessing large files also seemed to run a bit faster.

Keep in mind that the HHDD is still a spinning 7,200RPM disk drive so comparisons to a full time SSD would be apples to oranges as would the cost capacity difference between those devices. However, for what I wanted to see and use, the limited 4GB of flash does seem to provide a performance boost and if I needed full time super fast performance, I could buy a larger capacity SSD and install it. Im going to hold off on buying any more larger capacity flash SSD for the time being however.

Do I see HHDD appearing in SMB, SME or enterprise storage systems anytime soon? Probably not, at least not in primary storage systems. However perhaps in some D2D backup, archive or dedupe and VTL devices or other appliances.

Momentus XT Speed Bumps

Now, to be fair, there have been some bumps in the road!

The first couple of days were smooth sailing other than hearing the mystery chirp the HHDD makes a couple of times a day. Low and behold after a couple of days, just as many forums had indicated, a mystery system hang occurred (and no, not like Windows might normally do so for those Microsoft cynics). Other than the inconvenience of a reboot, no data was lost as files being updated were saved or had been backed up not to mention after the reboot, everything was intact anyway. So far just an inconvenience or so I thought.

Almost 24 hours later, same thing except this time I got to see the BSoD which candidly, I very rarely see despite hearing stories from others. Ok, this was annoying, however as long as I did not lose any data, other than lost time from a reboot, lets chalk this up to a learning experience and see where it goes. Now guess what, about 12 hours later, once again, the system froze up and this time I was in the middle of a document edit. This time I did lose about 8 minutes of typing data that had not been auto saved (I have since changed my auto save from 10 minutes to 5 minutes).

With this BSoD incident, I took some notes and using the X61s, started checking some web sites and verified the BIOS firmware on the T61 which was up to date. However I noticed that the Seagate Momentus XT HHDD was at firmware 22 while there was a 23 version available. Reading through some web sites and forums, I was on the fence on trying firmware 23 given that it appears a newer firmware version for the HHDD is in the works. Deciding to forge forward with the experiment, after all, no real data loss had occurred, and I still had the X61s not to mention the original T61 HDD to fall back to worse case.

Going to the Seagate web site, I downloaded the firmware 23 install kit and ran it to their instructions which was a breeze and then did the reboot.

It has not been quite a week yet, however knocking on wood, while I keep expecting to see one, no BSoD or system freezes have occurred. However having said that and knocking on wood, Im also making sure things are backed up protected and ready if needed. Likewise, if I start to see a rash of BSoD, my plan is to fall back to the original T61 HDD, bring it up to date and use it until a newer HHDD firmware version is available to resume testing.

What is next for my Seagate Momentus XT HHDD?

Im going to wait to see if the BSoD and mystery system hangs disappear as well as for the arrival of the new firmware followed by some more testing. However, when Im confident with it, the next step is to put the XT HHDD into the X61s which is used primarily for travel purpose.

Why wait? Simple, while I can tolerate a reboot or crash or data loss or disruption while in the office given access to copies as well as standby or backup systems to work from, when traveling options are more limited. Sure if there is data loss, I can go to my cloud provider and rapidly recall a file or multiple ones as needed or for critical data, recover from a portable encrypted USB device. Consequently I want more confidence in the XT HHDD before deploying it for travel mode which it is probably safe to do as of now, however I want to see how stable it is in the office before taking it on the road.

What does this all mean?

  • Simple, have a backup of your data and systems
  • Test and verify those backups or standby systems periodically
  • Have a fall back plan for when trying new things
  • Keep productivity in mind, at some point you may have to fall back
  • If something is important enough to protect, have multiple copies
  • Be ready to eat your own dog food or what you talk about
  • Do not be scared, however be prepared, look before you leap

How about you are you using a HHDD yet and if so, what are your experiences? I am curious to hear if anyone has tried using a HHDD in their VMware lab environments yet in place of a regular HDD or before spending a boat load of money for a similar sized SSD.

Ok, nuff said.

Cheers gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press), The Green and Virtual Data Center (CRC Press) and Resilient Storage Networks (Elsevier)
twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2024 Server StorageIO and UnlimitedIO LLC All Rights Reserved

Industry Trends and Perspectives: Tiered Storage, Systems and Mediums

This is part of an ongoing series of short industry trends and perspectives blog posts briefs.

These short posts compliment other longer posts along with traditional industry trends and perspective white papers, research reports, solution brief content found at www.storageioblog.com/reports.

Two years ago we read about how the magnetic disk drive would be dead in a couple of years at the hand of flash SSD. Guess what, it is a couple of years later and the magnetic disk drive is far from being dead. Granted high performance Fibre Channel disks will continue to be replaced by high performance, small form factor 2.5" SAS drives along with continued adoption of high capacity SAS and SATA devices.

Likewise, SSD or flash drives continue to be deployed, however outside of iPhone, iPod and other consumer or low end devices, nowhere near the projected or perhaps hoped for level. Rest assured the trend Im seeing and hearing from IT customers is that some will continue to look for places to strategically deploy SSD where possible, practical and affordable, there will continue to be a roll for disk and even tape devices on a go forward basis.

Also watch for more coverage and discussion around the emergence of the Hybrid Hard Disk Drive (HHDD) that was discussed about four to five years ago. The HHDD made an appearance and then quietly went away for some time, perhaps more R and D time in the labs while flash SSD garnered the spotlight.

There could be a good opportunity for HHDD technology leveraging the best of both worlds that is continued pricing decreases for disk with larger capacity using smaller yet more affordable amounts of flash in a solution that is transparent to the server or storage controller making for easier integration.

Related and companion material:
Blog: ILM = Has It Losts its Meaning
Blog: SSD and Storage System Performance
Blog: Has SSD put Hard Disk Drives (HDDs) On Endangered Species List
Blog: Optimize Data Storage for Performance and Capacity Efficiency

That is all for now, hope you find this ongoing series of current and emerging Industry Trends and Perspectives interesting.

Ok, nuff said.

Cheers gs

Greg Schulz – Author Cloud and Virtual Data Storage Networking (CRC Press), The Green and Virtual Data Center (CRC Press) and Resilient Storage Networks (Elsevier)
twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2024 Server StorageIO and UnlimitedIO LLC All Rights Reserved