Synology Backups.....

One of the most popular uses for a NAS is a place to store backups (Tape is dead!  Remember?) So now that the backups exist on <insert favorite NAS device>, how does one get that data off site?

Synology will back up to another CIFS share, RSYNC, or another Synology.

Using two virtual Synology devices I tested using one as a source and a 2nd as the destination.

Backing up a LUN (what Synology calls a "LUN Backup Set") , yielded a bunch of 4gb volumes.  I have yet to figure out if it is doing block level backups or not.  For instance, let's say one has a virtual machine living on an iSCSI LUN, if only a small amount of data is changed, how much is going to be backed up?  The entire VM?   The Entire volume?


If they Synology has a CIFS share, and that is told to backup (what Synology calls a "Network Backup Set"), it makes an exact copy on the receive box.  So that means no compression or no historical backups.

Two things really disappoint me.  The first being the logs and notifications.  All the information one gets is if the job completed or not.  No mention of the amount of changed data, time consumed, nothing!

Restoring: I haven't tried restoring the iSCSI volume yet.  However the CIFS share, it does a full restore of the entire volume!  One cannot pick and choose files or folders to restore.  The work around there, is to browse to the destination Synology and manually copy off the missing/corrupt data.  During my test I simply deleted a chunk of folders from source NAS, did a restore.  Surprisingly, it does only copy back the missing data, not the entire data set, as can be seen at on the progress meter.

Use a Synology NAS on physical hardware or as a VM!

The Synology DiskStation is written using the GPL licensing scheme, therefore it is open to third parties to manipulate and do feature adds.  Some people have ported the OS to run on most physical hardware and as a Virtual Machine.  The version emulates a DS3612xs, which is Synology's big boy 12 bay chassis.

I do like the Synology, it is one of the few entry level NAS's on the market to actually be on the VMware Hardware Compatibility List.  The App Store approach for plugins works well, and has some nice features.

I am not sure I would run this for production.  It MIGHT be easier to deal with than a FreeNAS or Openfiler.  It is however GREAT for learning about the product, and related items such as RSYNC, iSCSI, NFS, Media streaming servers, ect.

Here is the main site:
http://www.xpenology.nl/

Here are the instructions I followed:
http://patrickscholten.com/install-synology-dsm-esxi-5-x-virtual-machine/

Summarized install instructions for VMware ESXi:
-create a new custom VM using Linux 2.6 x64, 2gb ram, 1 cpu, use VMXnet3 nics, the data drive will be of type scsi.
-Upload the 32mb VMDK (and it's descriptor file) that has the ported DSM image on it, add it to the VM using disk type IDE

A few observations:
-Just like all Synology devices, one must have a DHCP server, else one cannot configure it, as they don't come preprogrammed with a static IP.
-Use the Synology Assistant to find the new device; as much as I hate installing extra apps on a PC, it is easier than doing an IP scan or looking through the DHCP server to find the device, and remembering to use http://ip.address:5000
-The device will alert you to new updates, but it will not apply them.  I assume it has to do with them not being ported.
-The app store works!
-I haven't attempted to load VMware tools.
-It detected my locally attached storage as type SSD, and my Xeon 54xx cpu's as Core i3's, no issues, just interesting.
-iSCSI does work.  Using a virtual DiskStation I was able to attach to it as an iSCSI target from the host ESXi machine.

hard drive benchmarks.....v1.2

More not super scientific benchmarking...

Dell PE2900, Perc 6i, 15k 146gb SAS * 8 drives RAID5

Dell PE2900, Perc 6i, 15k 146gb SAS * 4 drives RAID5
Interesting how little difference between 4 drives and 8 drives is.

Dell PE2900 on board SATA port to Hitachi 7200rpm 1tb drive.

Dell PE2900 on board SATA port to Intel 160gb SSD drive.
Interesting that write speed is about the same as the spinning drive, and writes are just over twice, but still can't compete w/ the 15k SAS drives RAID.  Is this a result of a poor SATA controller?

Openfiler, Optiplex 755, 750gb SATA 7.2k  iSCSI

Openfiler, Optiplex 755 1tb *2 SATA 7.2k RAID1 iSCSI


HP DL380, P410 w/ 512mb, 146gb 10k SAS *7 RAID5
I have no idea why the HP is falling on its face when it comes to read at 1mb.



Lenovo i5w/ 256gb mSATA

Dell Precision T5400 Sandisk 24gb mSATA on a mSATA to SATA adapter

Dell Precision T5400, Seagate 1tb Hybrid drive



Dell Laditude e6500, on Seagate Hybrid 750gb.  This machine has always seemed a little bit of a slug, so who knows on this one.


also see my previous posts of bench marks:
http://jungle-it.blogspot.com/2013/08/hard-drive-benchmarksv11.html
and
http://jungle-it.blogspot.com/2013/03/hard-drive-benchmarks.html

Databases for hosting a VMware environment.

SQL Express 2008+
-limited to use a single cpu & 1gb ram (aka performance issues may occur)
-10gb database limit size; a ceiling may be hit, but thus far I cannot find any sizing guides from VMware
-VMware recommend maximum for this is 5 ESXi hosts and/or 50 VM’s

Work Abounds:
Option A:
-Install vCenter on standalone server with SQL Express
-VMware Update Manager, install it on vCenter or break out to separate server with separate SQL Express
-Install VMware View Composer on a standalone server with SQL Express
The idea being that  two or three different SQL Express installs to spread the load around.  Hopefully that 10gb size limit would not be reached.

Option B:
-Use vCenter Virtual Appliance: VMware says it is compatible, it supports 100 hosts & 3000 VMs.  There might be issues in upgrading infrastructure components down the road, IE will VCA be compatible w/ View Horizon 6.0?  And if not will the upgrade of VCA be straight forward and not a rip & replace?  This option saves a Windows license, saves a from the 10gb database limit, saves from not having to purchase a full copy of SQL.  This approach is also somewhat new territory, and hasn’t been widely implemented.  Lastly Update Manger does not function in VCA, the method is to install it on another Windows server, which again needs to talk to a database either SQL or SQL Express. 

Option C:
-Spend money!  Buy SQL standard and another Windows License.   Be sure to limit SQL to not use ALL of the ram and CPU, also set the recovery mode to simplified data recovery, unless one wants to deal with all the SQL log files.

VMware vSphere Replication, a quick overview

VMware's vSphere Replication (VR), is a good way to duplicate VM's from one host/datastore to another.

The appliance comes with vSphere Essentials Plus and above.

The VM's are duplicated on an individual basis.  Meaning, one can do things like having the critical server replicated every four hours, but less critical ones every 24 hours.

VR can replicate either in the same datacenter or across a WAN.  For my quick testing I replicated a VM from my lab cluster, to another physical ESXi server on the the same subnet but a different VMware Cluster.  This meant I only needed one Virtualcenter Server and one vSphere Replication Appliance.

VR is an appliance so it installs much like any other appliance in no time at all.  Configuring VR was just a matter of telling it what VirtualCenter server to talk to, where the source and destinations are.

Configuring a VM for replication is a simple right-click and six questions.

This is what the destination datastore looks like after a successful replication.  The replicated VM does not show up in the machine inventory.  When browsing the respective folder, one may notice there is not .vmx file so there is no option to add it to inventory and power on the VM.  In order to use the replicated machine go to Home, vSphere Replication, "Replication Server", click the VR server, then the Monitor tab.  Highlight the VM in question, and choose recover.
Here are the options presented during the restore process.  One can also see status of the replication on this screen shot.  

This scenario only works to recover the VM's to the recovery server, it will not restore the VMDK's back to the original server.  One would have to copy off the VMDK to another storage to get the VMDK back to its original location.    It could recover the VMDK back to its original location if both ESXi server had access to the same storage.  In my lab, direct attached storage was in use.

For more information:

Backup Exec 2012 & VMware ESXi

Using Backup Exec 2012 (BES) to backup Virtual Machines (BES) to talk directly to the VMware environment (aka agentless).  It works fairly well.  One can restore individual files without installing the agent on the VM, the backup jobs continually give warnings about not being able to do granular restores without the agent.  Just to be clear, if one wants to restore the VMDK, click on the vCenter/ESXi host and hit restore, if one wants to restore files from the VM, click the server, then click restore.  Along that lines, while restoring the at the VM level, it looks like that is all one can restore; lets say one needs the VMX.  One would have to do a complete VM restore.
Notice only the VMDK is there for restoring.
It also appears that one must back up the whole VM or nothing.  In this case I only want to backup the one VMDK but not the second.
There is checkboxes next to each VMDK but once cannot uncheck them.
One can right click on a VMDK and choose the "include/exclude" option which brings up a new window, where it looks like a filter is created to exclude that VMDK, however one cannot click the "OK" button.

Another side note, BES has no idea what to do w/ the vCenter Management Appliance. 






OpenFiler...a Free NAS

OpenFiler (OF) is an open source file server.  One can use it for anything they would normally use a NAS for, it is much the same as thing as FreeNAS.  This one supports CIFS, iSCSI (block level as well!), NFS, and it can be joined to an Active Directory.  It doesn't to DNLA or any other media services that FreeNAS does.  It also doesn't do the ZFS file system.  Part of the reason why is that the development of OF has stopped.  Version 2.99.2 is the most current release.

My victim is a Dell Optiplex 755 desktop.  It has been upgraded to an Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz, 8gb of ram, an Intel PCIE dual port NIC, four hard drives, 250gb, 750gb, and a pair of 1gb drives.  The cpu and ram maybe over kill on this build, but I had it laying around so this was a good way to put it to use.  The goal of this build is to be shared storage for another VMware lab.

One could install the OS on a 4gb USB thumb drive, but others advise against it.  Although if one did a manual install of the OS and had the the swap partition on a different drive, I don't see why not.  So that being said, OF was installed onto the 250gb SATA drive.  One of the two ports of the dual port NIC is used for CIFS and management, the other port and the onboard NIC are to be used on the iSCSI VLAN.

I ran into a ton of issues; the software is really unpolished, and is basically beta level grade.  Rather than tell you all of my road blocks I will just tell you the fixes and what I learned.

-There is a bunch of updates to do via the GUI interface, reboot when done.
-When creating volumes, only 95% of the drive can be used.  Something is wrong with the coding, some say they fixed it by actually editing the HTML that is for the GUI, some create their partitions either via the CLI or w/ GParted.
-The final release is v2.99.2, however the link on the download page from SourceForge is v2.99.1; Here is a link for v2.99.2 http://sourceforge.net/projects/openfiler/files/
-One cannot create mirrored RAID sets in the GUI.  To fix the issue run the following command from the console:
conary update mdadm=openfiler.rpath.org@rpl:devel/2.6.4-0.2-1
This will install the correct mdadm files, once installed type the next command in.
ln -s /sbin/lvm /usr/sbin/lvm
This ensures that the GUI is populated correctly.
-Creating partitions can be frustrating because then never seem to take; the solution seems to be to either create them outside the GUI have the starting cylinder be 80 higher than the suggested.
-There are more updates, not available via the GUI, from the CLI: run these commands:
conary update conary
conary updateall
conary update openfiler
-at one point while trying to create a volume on the software RAID1, that page would never finish, and no matter what I did from that point I could create a volume.  Either creating the partition with GParted or one of the updates took care of that issue.

I have it presented to a VMware lab as an iSCSI target; thus far the only thing it is doing is a destination target for backups.  So far so good.  Near as I can tell there is almost no cpu usage during file transfers.  It lacks the ability to easily see network, cpu, and disk usage.
......more to come....

Veeam 7.x "FREE"

Some may have noticed a plethora of ads for Veem lately, and many of them say their product is free.  Well what it really is, that you get there full blown software for a trial period, but at the end of the trial you get to keep their "free software" Veeam Zip.

Veeam Zip, is a program to backup VM's into a single file.  It cannot be scheduled (at least through the GUI), there is no job log to go back to, one cannot include or exclude files, folders, or drives, it is the whole VM or nothing.

Once the trial period ends, changing the configuration becomes difficult.  For instance, I had a test ESXi server up for a while.   I cannot remove that test server from the Veeam GUI because it says it is in use by job "backup job1".  Ok, so I will just delete the backup job, Oh wait, can't do that because that portion of the program has been been crippled.

It is CPU intensive for the backup server.  I had two vCPU's assigned to the backup server and during the jobs it would have both of them at 100% utilized.  Upgrading to four vCPU's, made the backup job go faster and all four vCPU's hovered around 80% used.  In this test my throughput went from roughly 30Mbps to 38Mbps.  At this point Veeam reported that the "source" (meaning the source VM) was the bottle neck, which could be as the VM being backuped up as well as the backup server both live on a set of mirrored SATA drives.

How it works.  Once a job is started. 1. A Vmware snapshot is taken of the target VM.  2. The original VMDK for that target VM is mounted to backup server.  3. The backup takes place.  4. Target VMDKs are unmounted, ESX merges the snapshots.

I did play with the compression settings a bit.  Veeam does get ride of white space and the swap file, then compresses the backup.  Some of the VM's I was backing up saw roughly 30% decrease in space.  Switching the compression to maximum added another 5 minutes to a 15 minute job and took the backup file from 7.3gb down to 6.5gb.

Veeam Zip is a cool tool.  I forse using it instead of copying VMDK's around, or other ways to migrate VM's to different ESXi servers.  Or using it for a monthly backup in addition to another method; I am thinking of some smaller clients who are only using Agent/file based backup programs and aren't willing to spend the money to upgrade their software.
<pics to follow>
http://www.veeam.com/virtual-machine-backup-solution-free.html

FreeNAS usage part1

For a quick test I used Veeam Zip 7.0.x to backup my VM's to the FreeNAS.  Electricity usage spiked at 71 watts, at rest the server consumes a mere 61 watts.  It looks as though we are getting 30~40Mbps sustained transfer rates, Veeam showed spikes up to 70Mbps.  Currently, assuming I am reading the graphs right it is not CPU or ram bound, that being said perhaps I will switch to ZFS.  Also I don't have LACP/RoundRobin, or any sort of load balancing between the NICs on the FreeNAS. I have ESXi set up to use RoundRobin on two NICs.



FreeNAS build

I got a Lacie 1U NAS from a customer, it unfortunately died, the cpu fan quit working and the poor little Atom proc. melted itself.  So basically I got a 1U ITX case and power supply for free.  This gave me a good excuse to redo my shared storage in my home lab.  My requirements are that it have low power consumption, cheap, support iSCSI, and cheap.

I shopped around a bit for an ITX motherboard.  I settled on the Gigabyte GA-C1037n.  I paid roughly $103 for it shipped.  I choose this board because it has dual 1gbps NICs, it has more than one desktop ram slot, supports 16gb of ram (unfortunately it doesn't do ECC), it has an expansion slot (albeit 32-bit PCI an not PCI-X).  It only has three SATA ports, one of which is a 6gbps port.  So I am stuck at three drives, unless I use a SATA controller in the PCI slot, but MEH, if I need more space I will just put bigger drives in.  A 64bit cpu, as developers are stopping production of x86 code.  This cpu consumes a mere 17watts!  Compare that to a dual core pentium at 65 watts, or a quad core at 95.  

Celeron 1037u 1.8ghz, 1737 cpu mark, 2mb cache, 17w
Celeron 1007u 1.5ghz, 1379 cpu mark, 2mb cache, 17w
Atom D2700 2.1ghz 841cpu mark, 1mb cache, 10w
Celeron 847 1.1ghz, 985 cpu mark, 2mb cache, 17w
Intel e2160 Core2Duo 1.8ghz, 996 cpu mark, 1mb cache, 65w 

The ram was kinda sort free, as they were pulls from other projects,  so 6gb PC3 total (4gb & 2gb).  One day it will get upgraded to 16gb.  Unfortunately it is highly recommended to NOT run the ZFS file system with less than 8gb.  So UFS and 6gb for the time being, but more on that part later.

The first issue I ran into was the case need an appointment with Mr. Dremel as the sound card ports got in the way of the case.  Also the IO shield that came w/ the motherboard is too tall to fit.  The next issue was that it wouldn't power up.  The power supply that came with the case did not have the 28pin ATX motherboard connector nor did it have the 4pin ATX connector.  Unfortunately the 4pin connector is required for it to boot.  I attempted to make one by snipping a 4pin connector from a scrap power supply, and adapted it to a molex connector; no joy.  Purchased a new power supply from NewEgg for $30.  This case also has three fans in it, with a goofy two pin connector.  I ended up snipping that pig tall off of the old power supply and splicing it in on the new one, less than ideal but it will do.

FreeNAS 9.2.1 was installed on a 4gb USB thumb drive; turns out that a few of my 2gb drives (which is all that is required) where just a few bytes too small.  Two 1tb 7200rpm SATA drives are installed.  I added a Trendnet PCI 1gbps NIC, as I think what I want is to have this NIC for management, NTP, CIFS, etc.  The two onboards I will dedicated to iSCSI traffic, which is on a separate VLAN.  


New Genre of Computer Virus

I stumbled upon a new genre of computer virus today. The client called in saying printing was slow on their terminal server.  I logged onto  their terminal server; noticed the whole machine was rather slow.  Noticed in task manager that 100% of the CPU was consumed by an a program called "sysctrl32.exe" also noticed that there were four users logged in, each one had one instance of this program consuming 25%.  Researching this program came up with almost no results.  I then ran an Eset OnLine Virus scan, and it found a trojan.  Turns out this is a virus that mines BitCoins for some cybercriminal!  Brilliant! Kinda wish I had thought of it! :)

Shortcomings and notes of Backup-Exec 2012

-Simplified Disaster Recovery-It is a great idea.  To recover a damaged machine, simply boot up off a DVD that has a Windows PE environment, point it at either the Backup Exec Server (BES) OR the Backup Exec  backup files, and hit restore.  This is huge time saver; no longer does one need to install the OS, then install BES, then cat catalog the backup media, then restore.

However, this relies on the existence on a ".DR" file.  This file is ONLY created at the last full complete and successful backup.  So if the job has been erroring out for a while, you may be restoring from really old backups.  One cannot restore just the Windows System State, one must restore the system state with the entire c-drive.  Symantec's response on this is, that the system state requires files along w/ the registry and what not.  My response is well, yes, duh!  So when I click system state, it should backup/restore all that is necessary for a System State.  If I wanted to restore just a file out of there, say NTDIS.dat, I would choose that.

-Installing BES on a Active Directory Domain Controller (ADDC)-DON'T DO IT!  If your active directory gets damaged, and one needs to restore it, it normally requires going into Safe Mode or Directory Services Recovery Mode.  Well since BES was installed on a ADDC all of the services and backup jobs are tied to that AD account.  While one can get BES to launched by manipulating what credentials get used to start the service.  The backup jobs/media can be a different story.  Eventually in this particular case we had to rebuild the machine from scratch, and change the name of the machine to that of the previous machine, and put the DNS name in to "trick BES.  Then I was able to do a restore.  For this client, I am started using Windows Backup to backup the system state in addition to BES.
Oh, and changing the name of the machine, or changing it domain membership, usually breaks BES.  After fighting this issue for a while, we simply just uninstalled and reinstalled.  Supposedly it is an issue with SQL Express.

Symantec claims that restores can be done to dissimilar hardware.  Thus far I cannot get it to work.  We tried taking an SBS 2003 VM, and restoring it to a physical machine.  On a HP ML350 G5, the machine would boot to a black screen w/ a star moving across that would say "setup is preparing your computer".  Then a Dell PowerEdge 1900, we could never get past the disk partitioning portion.  We got past on the HP by manually preparing the volumes just as they were on the original machine.  Even restoring to a blank VM gave us grief.  At this point we bailed.

Reasons why Hyper-V is inferior to Vmware

****this post is unpolished, and will be randomly updated*******
I keep seeing traffic saying that Microsoft's Virtualization is free, or at least cheaper than Vmware.  Well, I going to make an attempt at debunking those statements.  Before anyone just dismisses this post on the merit of me simply being a Vmware fanboi; let me say that I was running Microsoft Virtual Server for years on my home lab dual Intel Pentium III server.  Yes that goes way back, even before the name change to Hyper-V.  Currently I am assisting in the administration of a small 2012 Hyper-V server farm.  Also I love the fact that another company is competing seriously with Vmware.  Competition keeps companies progressing in features and keeps costs "down".

Anti-Virus: Because Windows is the hypervisor, it should have Antivirus protection on it.  Their is a financial cost to having one more AV license, plus installing it consumes more ram, processor, and hard drive space, that should be used for VM's.  Vmware's ESXi is a harden appliance with almost no attack surface.  

Backup: Because Windows is the hypervisor, it should be backed up.  This adds the cost of another backup agent, and the cost of space of backing up one more machine.  One could argue, well to do it right the Windows HV host should ONLY be doing HV, and nothing else; therefore if it breaks it is easy to rebuild if necessary.  I fully agree, however, how long does it take to install Windows 2012, activate it, install all the updates, install AV, configure the HV roll?  Four hours?  Six hours?  

ESXi can be installed in under an hour.  ESXi because it is so small, and so quick and easy to install the vast majority of implementations don't bother backing it up the host.  For those that want to there is a command that dumps out the configuration out to a text file that can be imported at a later time.   The ESXi OS is so small that many installs are put on to a 2gb USB thumb drive/SD card.

Memory efficiency:  Because one must install Windows 2012/2008 on the bare metal, it consumes more ram, not to mention hard drive space; space better suited for VMs. The ESXi OS is so small that many installs are put on to a 2gb USB thumb drive/SD card.  The ram footprint is usually less than 1gb.  A 2gb minimum requirement is there to actually install ESXi.  

Hyper-V is simply not as efficient with ram as Vmware.  For instance, I have a client with a brand new install of Server 2012r2 running HV, in this case the host is also a member AD server.  It has 16gb of ram.  It has one Server 2008r2 VM with 10gb of ram assigned to it.  There are to XP VM's, one with 2gb and one with 1gb of ram assigned to them.  So 10 +2 +1 = 13gb of VM's leaving 3gb for the 2012 host, no problem right?  WRONG!  I cannot get both XP VM's to run at the same time, as there isn't enough ram.  Later on I was able to change the start up ram on both XP machines to 1gb, and change the dynamic ram to 512mb as a minimum and a 2gb maximum; this got all three machines to run simostainlsy.  With ESXi one could "over allocate" ram and run more than 16gb of allocated virtual ram.  In fact I often tell customers that they should be over allocating by 20%, but that is another post all to itself.
Vmware has Transparent Page file-where if more than one VM has a file in ram, and it is identical for another VM, only one copy of that file is stored in ram, and pointers assigned to it.  Memory compression-files in ram are actually compressed (kinda like WinZip).  Memory Balloon driver-if the host is running low on ram, it will trick the VM to move files in ram that are seldomly accessed to its swap file (aka Windows Swap file, of the VM).  


CloudCred

Here is a "fun" way to learn about cloud related technology.  It is sponsored by VMware, but it is somewhat vendor agnostic.  For instance there is Amazon's AWS tasks.

Vmware Certified Professional..now called VCP5-DCV

I finally signed up and took the Install/Configure/Manage class for VMware.  This class costs an MSRP of $3850, lasts apx. 40 hours, and is required to take if one wants to take the VCP certification test.
 
So I kind of new some of this, but it is more clear now.  IMHO, it was more of a Vmware 101-105 class.  It only scratches the surface in preparing one for the exam.  For instance, I took a practice exam, literally only a dozen questions out of the 60 where covered in the class.  Our instructor admitted that in order to truly prepare for the exam one should take the Optimize/Trouble shoot class and the install class will not adequately prepare one for the exam.  Sadly it is another week long coarse; however what it does is it goes deep into the features we don’t use, as all of our customer fall into the SMB category, thusly as do our skill sets.  We never use technologies such as Site Recovery Manager, Fault Tolerance, or the NV1000 to name a few. 

Great article talking about some of the differences in the VCP program and vSphere v5.5 changes.

VMware Partner Exchange…….
-Early registration ends Jan. 6th (save $600)
----exams are 75% off when taken there!
----Boot camp classes are 60% off (the optimize class is not offered, there are some View classes)

ESXi v5.5 and SSD's

Two great new features with v5.5:

VSAN: This is a dynamic shift if storage methodology, for the past 10 years or so we have been pushing people to shared storage SAN & NAS, for many reasons; flexibility, speed, shared access, dynamic sizing, etc.. etc..  Also if one wanted to take advantage high availability aka vMotion (where your virtual machine can float between VMware servers). 

No longer does one need shared storage for a Highly Available VMware cluster!  VSAN is essentially another software SAN that lives on ESXi.  I did say "another"; products like LeftHand/HP VSA, RocketVault, even FreeNAS, and OpenFiler, just to name a few.  Even VMware tried this once before, their VSA appliance was tried, and was ultimately given a death sentence.  VMware's VSA's weak points were that it was limited to three hosts and the licensing costs neared what one could buy an entry level SAN for.

So how does VSAN differ than VSA or any other software storage product?  It uses 3 to 8 nodes to contribute to the storage pool; note any number of devices can attach to the storage pool.  Also each contributing server needs to have direct attached storage and SSD.  Lastly, this product is integrated in the hypervisor, it is not an appliance/VM running on top of the hypervisor. 

At the time of writing this blog, the product has been in beta for quite sometime, since VMworld 2013.  The beta is a free and open product to test.  I don't like that one NEEDS to have SSDs; I understand why, the whole reason is to make replication and higher IOPs.  It is just that enterprise level SSD is expensive.  It also is a pain that one must have at least three hosts; the reason for it is to prevent the 'split brain syndrome' (where there is a disconnect, and both parties think they are the 'master').  Lastly, official pricing/licensing hasn't been released but more than likely it will be an advanced feature that won't be offered in the Essentials/Standard packages.  Those three things make it harder for the SMB to deploy this feature.  It is easier to justify spending dollars on a box where one can point to and say that: "this is what we spent $20k" on vs. PDF file with license numbers on it.

Speaking with a peer, they were testing using Intel 910 PCIE SSD cards, and their results showed that VSAN was much faster than their NetApp.  Which proves the theory that moving storage back to local host, closer to where it is needed can be faster.

FLASH READ CACHE: http://www.vmware.com/products/vsphere/features/flash.html  In a nut shell if there is SSD in the system one can set a chunk of that drive aside to be used as cache for any/each VMDK to be used as cache.  It is only read-cache, not write cache.  It is set at the VM level; there is no cluster/vAPP wide setting that can quickly be applied.  So if one has dozens of VM's this becomes a pain.

In my lab, I was about to deploy this feature, however like all v5.5 new features it can only be manipulated in the Web Client, it can only be configured for VM's of hardware level 10 VM's; again flipping a VM to hardware level 10 means that it cannot be manipulated via the thick/c# client.  Also the SSD drive must be blank before enabling it.  In my lab I already the SSD drive in use by Host Cache and moved all of the VM's swap file to the SSD.  Eventually I will get around to undoing those settings, formatting the SSD drive, turning on Flash Read Cache, then turn Host Cache, and relocate the swap files to SSD.  This SSD drive is now unavailable for anything else; Flash Read cash, and host cache, it is not a datastore, so one cannot relocate VM swap files there or anything else.