It's a story that has been repeated many times: You buy a shiny new storage system..... and it is beautiful.
Then... a disk fails, which takes just the tiniest bit of shine off.
No problem you declare! You place a service call and the disk is replaced. So far so good.
But then as the vendor service representative is walking out the door, it suddenly occurs to you... hey, that person is taking away the failed disk. Doesn't that disk have my data on it?
The short answer is that unless you have purchased self encrypting drives or are encrypting your data prior to writing it, then that failed drive will almost certainly contain some readable data. How readable will depend on the product. If the disk contains de-duplicated compressed data, it would present a great (but I suppose not insurmountable) challenge to any would be data snooper. But a failed disk removed from a standard RAID array, would contain data in sequential chunks (that are perhaps 256 KB in size). Whether that would be useful is another question.
So what to do?
First up, every responsible vendor takes great pains to ensure failed hard drives are not simply thrown in the dumpster or sold in job lots. As Railcorp in Australia found out the hard way (when they started selling off the media they had in the lost and found department) not controlling media with client data is a very bad idea. Instead responsible vendors usually return failed drives either to the original manufacturer (to get a warranty rebate) or to a reutilization center (either their own, or a third-party). In either case, there is a financial benefit to them to do this. The shipment will be done in a secure fashion and any disk drive that can be repaired will be thoroughly wiped. If not it will be securely destroyed. Again, all the major vendors should be able to produce a policy document explaining how this is done. For the majority of clients out there, I personally think this is good enough.
But what if you don't think this is good enough? What if your data is way too sensitive to take any risks?
Simple answer: Keep the failed disks.
A quick Google search came up with lots of easy to find programs from most major storage vendors. Just search for something like disk retention service (retention is the key word here). Here are some examples:
The only fly in the ointment is that these services are generally not free... and if you realize this only after the first drive has failed, you may find yourself negotiating with your vendor on price, well after the main purchase is complete. The only exception I have found so far is that IBM Australia lets you retain failed drives for free, provided the machine is covered by a Service Pac.
Of course maybe you knew this already and have always retained failed drives, but now your store-room is slowly filling with failed disks. Now what? Well I do not suggest you do this, but I sure laughed while watching it (sorry if there is an advertisement before-hand):
Instead Google search for secure hard disk shredding or secure hard disk recycling. Examples I found in Australia very quickly ( I have not contacted or dealt with either of these) included this one and this one. I am sure there are plenty of choices out there.
IBM has today announced a whole swag of planned new features across the entire IBM Storage product line. You can read the announcement letter here and I have also dropped the text at the bottom of this blog post (to save you clicking on the link).
It's a very impressive list, but to hone in on a few of the more exciting offerings:
IBM Easy Tier will be enhanced to cache hot data in SSD storage installed in a client server. Looks like it will initially be a combination of DS8700/DS8800 and AIX with or Linux servers. I am sure there are plenty who will immediately think of EMC VFCache, so I am keen to get more details so I can see how the two compare. If you are curious in the meantime, check out this EMC fact sheet and then read this fascinating interview with the CMO of FusionIO.
A new high density storage module will be made available, initially I suspect for the DS8800. This is a really important step as we are seeing a lot of new technologies emerging in the SSD space. This is because the technical requirements of SSD don't always line up with the architectures of existing storage controllers, so a custom built enclosure designed just for SSD makes perfect sense.
The IBM XIV will be enhanced with the ability to cluster multiple XIVs together and migrate volumes non-disruptively between them. The non-disruptive volume migration is a great new feature which should definitely help with swapping XIVs out as new models come available.
There are plenty of other new features as well, so check out the announcement letter reproduced below:
IBM® intends to support a number of new enhancements to a variety of IBM storage systems in the future. These enhancements will leverage innovative research on intelligent algorithms, automation, and virtualization that is being incorporated into products in the IBM storage portfolio. The statements of direction highlighted here are intended to provide a glimpse into the IBM storage roadmap for selected product capabilities.
IBM intends to deliver:
Advanced Easy Tier™ capabilities on selected IBM storage systems, including the IBM System Storage® DS8000® , designed to leverage direct-attached solid-state storage on selected AIX® and Linux™ servers. Easy Tier will manage the solid-state storage as a large and low latency cache for the "hottest" data, while preserving advanced disk system functions, such as RAID protection and remote mirroring.
An application-aware storage application programming interface (API) to help deploy storage more efficiently by enabling applications and middleware to direct more optimal placement of data by communicating important information about current workload activity and application performance requirements.
A new high-density flash storage module for selected IBM disk systems, including the IBM System Storage DS8000 . The new module will accelerate performance to another level with cost-effective, high-density solid-state drives (SSDs).
IBM intends to extend IBM Active Cloud Engine™ capabilities to:
Allow files on selected NAS devices to be virtualized by SONAS and Storwize® V7000 Unified. Virtualization capabilities provide access across a unified global namespace, while facilitating transparent file migrations in parallel with normal operations. This capability will help provide customer investment protection as clients continue to leverage their existing NAS assets while exploiting the capabilities of IBM Active Cloud Engine .
Enable file collaboration globally via IBM Active Cloud Engine . This capability will help enhance productivity where users at geographically dispersed locations can both share and modify the same file.
IBM intends to deliver Cloud features to SONAS and Storwize V7000 Unified to support:
Web Storage Services, a standards-based object store and API that implements the Cloud Data Management Interface (CDMI) standard from Storage Networking Industry Association (SNIA) to support the implementation of storage cloud services.
Self-service portal designed to speed storage provisioning, monitoring, and reporting.
IBM intends to support an increased scalability of capacity, performance, and host bandwidth by clustering IBM XIV® Gen3 systems together and providing the capability to migrate volumes across the cluster without disrupting applications. Management of the cluster will remain simple with consolidated views and shared configurations across the systems. These capabilities are intended to help clients address the scalability and management requirements for effective cloud computing.
IBM intends to extend NAS data retention enhancements for IBM Storwize V7000 Unified and IBM SONAS to provide file "immutability" to help support file integrity from the time the file is designated as immutable through its lifecycle. Immutability is intended to secure files from inadvertent or malicious change or deletion.
IBM intends to enable Real-time Compression for block and file workloads on Storwize V7000 Unified systems. This enhancement is designed to help clients experience the same high-performance compression for active primary block and file workloads on Storwize V7000 Unified that is being announced for block workloads on Storwize V7000. IBM Storwize V7000 Real-time Compression is designed to deliver enhanced storage efficiency with potential benefits including lower storage acquisition cost (because of the ability to purchase less hardware), reduced storage growth, and lower rack space, power, and cooling requirements.
All statements regarding IBM's future direction and intent are subject to change or withdrawal without notice, and represent goals and objectives only. The information in the above paragraphs are intended to outline our general product direction and should not be relied on in making a purchasing decision. The information is for informational purposes only and may not be incorporated into any contract. This information is not a commitment, promise, or legal obligation to deliver any material, code, or functionality. The development, release, and timing of any features or functionality described for our products remains at our sole discretion.
One common question that I hear on a regular basis regards the availability of an SRA for VMware SRM 5.0 when using Storwize V7000 or IBM SVC running V6.3 firmware. This combination is currently unsupported as per the alert found here.
The good news is that there are now IBM SRAs available for clients running SRM in combination with V6.3 firmware. While this combination is still not listed on the VMware support matrix found here, you can download the SRAs direct from IBM if your need is urgent.
A few weeks ago I wrote a piece called How to spot an old IBMer. It was a sort of reminiscence about my early days with IBM but it turned out to be one that really touched a chord with many Big Blue veterans. In fact the response was overwhelming, I have never received more hits or more comments for anything I have written. It was also pleasing that these responses were almost universally positive.
So it's ironic that today I am becoming an ex-IBMer.
Yes it's time for me to move on, so I have decided to try something new. I am joining a really exciting IT startup called Actifio.
So for all of you who have worked with me and helped me over the past 23 years: Thank you. It has been an honor to work at IBM and I wish Big Blue and all who continue to work there, nothing but success and happiness.
So you need to do some disk performance testing? Maybe some benchmarking? What tools are out there to help you out? Well I am glad you asked... here are some that I use on my daily travels:
IOmeter is an old classic, with emphasis on the word old. At time of writing, the most recent update was from 2006. However it remains very popular mainly because it is free and easy to use.
Some tips when using IOmeter:
On Windows, IOmeter needs to be run as an Administrator, which seems to be the most common mistake people make (not running as Administrator means you don't see any drives). You can only run one instance of IOmeter in Windows, which means if multiple users logon to the same server, only one user can run IOmeter. You also really need to run IOmeter with a queue depth ( or number of outstanding I/Os) greater than one, with multiple workers. If you don't, you will not be able to drive the storage to saturation. For instance here are some results running 75% read I/O, 0% random, 4 KB blocks on a Windows 2008 machine with 4 workers. In each case against the same 128 GB volume on a Storwize V7000 backended by 4 x 300 GB SSDs in a RAID10 array. In each case I let the machine run for 10 minutes before taking the screen capture to ensure the performance was steady state and not peaking.
Firstly I used a queue depth of one. Aggregate performance was around 27000 IOPS.
Then I used a queue depth of 10. Aggregate performance was around 81000 IOPS.
I then used a queue depth of 20. Aggregate performance was around 113000 IOPS.
What I am trying to show is that taking the defaults (one worker with a queue depth of 1) will not drive the storage to a useful value for comparison... you need to do some tuning and some experimenting to get valid results. At some point increasing queue depths will not improve performance (it may actually decrease it).
There is an alternative to IOmeter called IOrate (created by an EMC employee). It is also very popular and appears to still be in active development. It is not unusual to see IBM performance whitepapers that used IOrate to generate the workload.
This is a fairly recent tool that I have not had a chance to try out (due to time pressures). The tool uses virtual machines under VMware to generate the I/O and includes some very nice workload capture and playback tools as well as reporting tools.
Jetstress is a benchmarking tool created by Microsoft to simulate Microsoft Exchange workloads. I like the fact you can configure it to run for very long periods and it has a more real world feel about it than just running empty I/Os. You can get the base software here, but you will also need some files from a Microsoft Exchange install DVD (or from an installed instance of Microsoft Exchange). If you cannot get to those files you cannot complete the startup process inside Jeststress.
Oracle offer a tool on their website called Orion, which will simulate the workload of an Oracle database. You can get the tool from here (although you will need to create a free Oracle user account before you can download it).
SDelete is not a benchmarking tool or a performance modelling tool. But it is a great way to generate I/O with very little effort. Just create a new drive in Windows and then run SDelete against it with the -c parameter. This parameter is used for secure deletion, so generates random patterns (which is real traffic - albeit 100% sequential writes). The syntax is like:
(updated April 20, 2012 - I found in version 1.6 of SDelete the meaning of the -z and -c parameters got swapped. In version 1.6 if you want random patterns use -c, if you want zeros use -z. In previous versions it is the other way around!).
Just doing file copies is probably the worst way to generate benchmarks, especially as a single copy is usually a single threaded operation.
I am sure there are plenty of other tools out there to generate benchmarks and simulate workload. My main concern with many of them is that synthetic (artificial) workloads do not reflect real world workloads.
If you work (or have worked) for IBM then you have probably met many old timers. IBMers who have been with the company for 25 years or more (or even 50!).
But how do you spot an old IBMer?
Is it by the cut of their suit? Not sure about that anymore.
An IBM General Systems Division marketing rep in New Jersey in 1978.
It's certainly not by their extensive beards.
Development of the 3800 printer, taken in the early 1970s by Ray Froess (http://www.froess.com/IBM/3800printer.htm)
Is it by the size of their laptop? I hope not!
IBM 5100 Portable Computer (1975)
No... you can spot them by their use of certain words and phrases.
Here are a few I can think of... you may know more. Try this out as a test on someone who you think is an old IBMer and see how they go:
1) While showing a powerpoint presentation they keep saying they are showing foils (despite having not seen an overhead projector in over 10 years).
2) They refer to disk storage as DASD (pronounced Dazz-Dee).
3) They still call a Sales Rep a Marketing Rep (check out Buck Roger's book The IBM Way to see why).
4) They refer to their inbox as their reader (see #6 below).
5) They refer to the IBM corporate personnel database as callup (it has been a Web based application called BluePages for around 15 years).
6) If you say I will PROFS you (or I will send you a PROFS mail), they don't blink an eye-lid (PROFs was IBM's Mainframe based mail system, replaced by OfficeVision which was replaced by Lotus Notes in the 1990s).
7) If you say you F4ed or PF4ed an email... they know what you mean (it meant that you deleted it in PROFS/OfficeVision).
8) They reveal they are a veteran of IBM Typewriters by regaling you with their knowledge of Selectric Rotate Tapes.
We just updated our Cisco MDS9509s to NX-OS 4.2.7b (from Cisco SAN-OS 3.3.1c) and now we are getting emails from this source: GOLD-major.
The actual message looks like this:
Time of Event:2012-03-05 15:07:21 GMT+00:00 Message Name:GOLD-major Message Type:diagnostic System Namexxxx Contact Namexxx@xxx.com Contact Emailxx@xxx.com Contact Phone:+61-3-xxxx-xxxx Street Addressx Road, xxxx, VIC, Australia Event Description:RMON_ALERT
WARNING(4) Falling:iso.220.127.116.11.18.104.22.168.1.10.18366464=2401032512 <= 4680000000:135, 4 Event Owner:ifHCOutOctets.fc4/5@w5c260a03c162
So who is GOLD-major?
GOLD actually stands for Generic OnLine Diagnostics. From Cisco's website: GOLD verifies that hardware and internal data paths are operating as designed. Boot-time diagnostics, continuous monitoring, and on-demand and scheduled tests are part of the Cisco GOLD feature set. GOLD allows rapid fault isolation and continuous system monitoring. GOLD was introduced in Cisco NX-OS Release 4.0(1). GOLD is enabled by default and Cisco do not recommend disabling it.
So in our example GOLD is actually reporting a major event (to do with exceeded thresholds, in this example utilisation on interface fc4/5).
Most clients using Cisco MDS switches are now moving to NX-OS (over SAN-OS, the name Cisco used for MDS firmware between version 1 and version 3) so this question will become more common. I am working on a post that discusses recommended versions (and the sunsetting of SAN-OS), so expect something soon. If on the other hand you are thinking.... how do I setup call home on a Cisco MDS switch? The information for NX-OS is here.
Curiously my brain cannot help itself, when I hear Gold Major I think it means Gold Leader which leads me to Red Leader which leads me to Red October. Maybe it's just me? Enjoy:
Because if a product uses a 32 bit counter to record uptime, and that counter records a tick every 10 msec, then that 32-bit counter will overflow after approximately 497.1 days. This is because a 32 bit counter equates to 2^32, which equals 4,294,967,296 ticks. If a tick is counted every 10 msec, we create 8,640,000 ticks per day (100*60*60*24). So after 497.102696 days, the counter will overflow. What happens next depends on good programming: normally the counter just starts again, but worst case a function might stop working or the product might even reboot.
Fortunately we are seeing less and less of these issues but just occasionally one still slips out. Recently IBM released details of a 994 day reboot bug in the ESM code of some of their older disk enclosures (EXP100, EXP700 and EXP710). Details about this bug can be found here. What I find interesting is the number of days it takes to occur, since 994 is actually 497 times two. This suggests that this product records a tick every 20 msec. This meant we got past 497 days without an issue but hit a problem after exactly double that number. So if you still have these older storage enclosures, you will need to reboot the ESMs (after checking the alert).
I googled 497 to see what images that number brings up and was amazed to find the M-497 jet powered train. More details on this rather interesting attempt at speeding up the commute home can be found here and here. It adds a whole new meaning to keeping behind the yellow line.
If you have combined vSphere 5.0 with XIV, then you may want to try out the new IBM Storage Provider for VMware VASA (vSphere Storage APIs for Storage Awareness). You can download the installation instructions, the release notes and the current version of the IBM VASA provider from here. Clearly because VASA is introduced in vSphere 5.0 your VMware vCenter also needs to be on version 5.0.
Now IBM have had a vCenter plugin for a very long time (which I have written about here, here and here) and while you still need that plugin if you want to do storage volume creation and mapping from within vCenter (as opposed to using the XIV GUI), the VASA provider makes storage awareness more native to vCenter. This is a very important step. It means instead of using vendor added icons and tabs (like the IBM Storage icon and the IBM Storage tab that are added by the IBM Storage Management Console for vCenter), you just use the default vCenter tabs.
Right now version 1.1.1 of the IBM VASA provider delivers information about storage topology, capabilities, and state, as well as events and alerts to VMware. This means you will see new additional information in three tabs: Storage Views, Alarms and Events.
After installing and setting up the VASA provider, in vCenter select your VMware cluster, go to the Storage Views tab and select the view Show all SCSI Volumes (LUNs) there are four columns with more information. The Committed, Thin Provisioned information, Storage Array and Identifier on Array (indicated with red arrows) comes straight from the XIV (hit the Update button at upper right if you are not seeing anything yet). This is really useful information as it lets you correlate the SCSI ID of a LUN to an actual volume on a source array. Here is a cut-down view of that extra information:
If you want a larger screen capture you can find one here.
The Task & Events and Alarms tabs will also now contain events reported by the VASA provider such as thin provisioning threshold alerts (although if you have just installed the provider you may see nothing new, as nothing has occurred yet to provoke an alert or event).
As usual I have some handy tips on the steps you will need to take to get VASA going:
First up you will need to identify a virtual machine to run the provider on (or just create a new one). I chose to deploy a new instance of Windows 2008 from a template. Because the VASA provider communicates to vCenter via an Apache Tomcat server listening on port 8443, that port needs to be free and unblocked. This also means you should not run the VASA provider in the same instance of Windows as the vCenter server (see below for more information as to why).
Download the IBM Storage Provider for VMware VASA as per the link above (use version 1.1.1, see the user comments in this post for details about a bug in version 1.1.0).
Install the provider in the Windows VM you created in step 1. The tasks are detailed in the Installation Instructions, but it is a simple follow-your-nose application installation. As per most XIV software packages, it will install a runtime environment (xPYV which is Python) as part of the install.
Now we need to define the credentials that VMware vCenter will use to authenticate to the IBM VASA Storage Provider. These should be unique (and are not an XIV userid and password - this is only between vCenter and the provider software). In my example I use xivvasa and pa55w0rd. The truststore password is used to encrypt the username and password details (so that they are not stored in plain text). Open a Windows command prompt (make sure to right select and open it as an Administrator) and enter the following commands:
cd "C:\Program Files (x86)\IBM\IBM Storage Provider for VMware VASA\bin" vasa_util register -u xivvasa -p pa55w0rd -t changeit
Don't close the command prompt, because we now need to define the XIV to the IBM VASA provider.
You need the IP address of your XIV and a valid user and password on the XIV that can be used to logon to the XIV. So in this example my XIV is using 10.1.60.100 and I am using the default admin username and password (which I know does not set a good example). This is the command you need to run:
If this command fails, reporting your firmware is invalid, you are probably using the original 1.1.0 version of the VASA provider, go back to the IBM Fix Central website and make sure you have the latest version (at least version 1.1.1). If it reports the firmware cannot be read, make sure you are running the Command Prompt as an Administrator.
Once you successfully added the XIV to the provider, you need to restart the Apache webserver. Do this by starting the services.msc panel and looking for the Apache Tomcat IBMVASA service as pictured below. Stop it and then start it. Once you have done that you can logoff from the VASA VM.
Now connect to your vSphere Client (which needs to be on at least version 5.0.0) and from the Home panel, open the Storage Providers panel.Then select the option to Add a new provider. The URL needs to include the correct port number (by default 8443), so it will look something like this (where the provider is running on 10.1.60.193). Note also that the VASA provider version number is in the URL, so if you upgrade the provider you will need to change the URL (currently v1.1.1):
The Login and password should match the user id and password you defined in step 4 (remember it is not logging into the XIV, it is logging into the VASA provider).
If you get a message saying your user id and password are wrong, you probably forgot to stop and start Apache in step 6 above. If you succeed you should see a new provider listed. Highlight the provider and select sync to update the last sync time.
Your setup tasks are now all completed. Now go and explore the panels I detailed above to see what new information you have available to your vCenter server.
Why a separate server for the VASA provider?
The IBM VASA provider uses Apache Tomcat, which by default listens on port 8443. However since vCenter already has a service listening on port 8443, it means we have a clash. I googled and found the Dell and Netapp VASA providers also listen on port 8443 and they also recommend separate servers. I noted Fujitsu's provider uses a different port but still requires a separate server. So it seems if you have multiple vendors you will either have to spin up a separate server for each vendors provider, or start playing with changing the port number. The installation instructions for the IBM VASA Provider explain how to change the default port number if you are truly keen.
Many years ago I picked up a book that literally blew my mind. It was the Cuckoo's Egg by Clifford Stoll and it's a genuine classic, a true tale of hackers and how one was tracked down in the very early days of the internet.
Now the story is about events in 1986, so it captures the state of technology at the time (which rather dates the book), but wow, what a great story.
So why mention the book? Well apart from the fact that it is well worth a read, the key issue that Clifford saw again and again was default passwords. The hacker would identify a target and then try to logon using default IDs and default passwords, usually with great success.
Now I have blogged in the past about the determined (but often ignored) way that Brocade switches berate you into changing default passwords. But pretty well all products need to do this, as they all have the same issue (and a truly problematic counter-point). You absolutely need to do two things with every product in your data center:
Change the default passwords on every device you deploy.
Record what those passwords got set to (preferably using a logical or physical password safe).
Now don't laugh, but forgotten/lost passwords on data center kit (like switches) is a VERY common problem. When I worked in the IBM Storage Support team I took calls EVERY WEEK from clients who had devices they could not logon to, for all manner of reasons. For some, supplying them with the default passwords saved them (and condemned their employer?), but for others they needed much more detailed assistance.
My preferred solution to this challenge is to use external authentication (like LDAP) but being able to reset passwords with an external tool is also a nice option to have available.
The reason I started thinking about this is a nice tool IBM offer for the Storwize V7000 called the Initialization Tool that you can download from here. Using this tool you can reset the password of the Superuser ID on a Storwize V7000 back to the default (passw0rd). The tool runs on a USB key. After requesting the tool to help you to reset the superuser password, you insert the USB key into the Storwize V7000, wait for the orange indicator light on the relevant node canister to stop blinking and the task is complete. Then put the USB key back into your laptop and run the init tool again to get a completion report that should look like this:
This is great to rescue customers who have lost their passwords, but the question then gets raised: Can I block this?
My first response is: if you are concerned about unauthorized people with malicious intent placing USB keys into your Storwize V7000, then don't let them into your computer room (presuming you can spot them by the colour of the hat they are wearing). If that is not an option, lock the rack that the Storwize V7000 resides in (change control does have its benefits). If that is not an option, there is one more alternative, but it is a tad extreme.
What we can do is prevent password reset via USB key (or in the case of the SVC, via the front panel). We do this by issuing the following CLI command: setpwdreset -disable
In the following example, I confirm that password reset is possible (value 1), I then disable it and confirm that password reset is no longer possible (value 0). If curious I could then get some help on that command:
Only if your paranoia is matched by your attention to detail.
My reason to hesitate recommending it is simple: If you prevent password reset and then forget your password (and have no other local Security Administrator accounts), you have locked the door and thrown away the key. Far better to physically lock the rack.
In the end though, your company needs to set a policy that is actively enforced (with no exceptions). So get to it.
When IBM brought out the SAN Volume Controller (SVC) in 2003, the goal was clear: support as many storage vendors and products as possible. Since then IBM has put a huge ongoing effort into interoperation testing, which has allowed them to continue expanding the SVC support matrix, making it one of the most comprehensive in the industry. When the Storwize V7000 was released in 2010 it was able to leverage that testing heritage, allowing it to have an amazingly deep interoperation matrix on launch date. It almost felt like cheating.
However I recently got challenged on this with a simple question: Where is the VNX? If you check out the Supported Hardware list for SVC V6.3 or Storwize V7000 V6.3 you can find the Clariion up to a CX4-960, but no VNX.
The short answer is that while the VNX is not listed there yet, IBM are actively supporting customers using VNX virtualized behind SVC and Storwize V7000. If you have a VNX 5100, 5300, 5500, 5700 or 7500 then ask your IBM pre-sales Technical Support to open an Interoperation Support Request. The majority are being approved very quickly. The official support sites that I referenced above will be updated soon (but don't wait, if you need support, ask for it). IBM is working methodically with EMC to be certain that when a general publication of support is released for VNX (soon!), both companies will agree with the published details.
And for the wags who think that this is a ringing encouragement to buy VNX, you would be missing the point. You cannot be a serious Storage Virtualization vendor if you are not willing to support your clients purchasing decisions, regardless of which vendor they buy their storage from. IBM have been staying that course and demonstrating that willingness since 2003. It's a pretty good track record and one that they are determined to maintain.
I have updated my IBM Storage WWPN Determination Guide to version 6.5. You can find the updated guide on IBM Techdocs here.
The main change is that new DS8800s are now presenting slightly different WWPNs, so I added three new pages to describe the changes.
If this guide is new to you, its purpose it to let you take a WWPN and decode it so you can work out not only which type of storage that WWPN came from, but the actual port on that storage. People doing implementation services, problem determination, storage zoning and day to day configuration maintenance will get a lot of use out of this document. If you think there is an area that could be improved or products you would like added, please let me know.
It is also important to point out that IBM Storage uses persistent WWPN, which means if a host adapter in an IBM Storage device has to be replaced, it will always present the same WWPNs as the old adapter. This means no changes to zoning are needed after a hardware failure.
I also host the book on slideshare, so you can also view and download it from there:
Its been a long time coming, but I finally joined the cult of Mac in the form of a new MacBook Pro. Having not used an Apple Mac for over 15 years, I must say I am truly loving what they have done with the operating system and the hardware (my last Mac was a Mac SE bought in 1990).
Now this post is not a rant from a new convert to everything Apple. In fact my main gripe is that what you rapidly discover when you move to Mac OS is that not every piece of software is going to work in your new world. While Lotus Notes and Sametime have very nice Mac versions, my day to day work involves IBM Storage and there are several tools that I need that are Windows only. These include Capacity and Disk Magic (used to size solutions) and eConfig (used to order IBM products). This means for certain applications I need to use a Hypervisor (such as VMware Fusion or Parallels).
But what about managing IBM Storage? Well I have some good news on that front:
SAN Volume Controller and Storwize V7000: Because these products are managed from a web page, they are operating system agnostic. To be clear, officially only Firefox 3.5 (and above) and IE 7.0 and 8.0 are supported (support details are right at the bottom of this page while setup details are here). Since IE is no longer available for Mac, you should install Firefox (or try out Safari or Chrome, I have tried all three without issue).
XIV: The XIV GUI is available in a native Mac OS version from here. The release notes state that the XIV GUI works on Mac OS X 10.6 but I am happily using it on Mac OS X 10.7 (Lion). The Mac OS X installation process is simply beautiful (just drag and drop, one of the truly nice features of Mac OS X) and of course it works just as nicely on Mac as it does on the other supported operating systems.
Drag and drop done right.
Attaching OS X to IBM Storage
Of course maybe you want to attach your Mac OS X box to IBM Storage. If you visit the SSIC you will find IBM supports OS X on pretty well it's entire range including SVC, Storwize V7000, XIV, DS3500 and DCS3700. Mainly these use the ATTO HBA and multipath device driver. If your particular setup is not there, get your IBM Pre-sales Support to open a support request, depending on your request, approvals are normally very fast.
Of course I have to mention the iPhone and iPad. IBM have the XIV Mobile Dashboard for both devices, which I previously blogged about here (iPad) and here (iPhone). These are really elegant apps that even have a cool YouTube video.
Of course now I want all the goodies promised in Mountain Lion. With the convergence of OS X and iOS, I would love to see even more converged tools. A man can dream....
There is a demo mode, but right now there is no tick box to activate it. Simply use the word demo in all three fields at login. In other words:
IP address: demo User ID: demo Password: demo
2) Retina display requirement
The Mobile Dashboard was written for the Retina display (that comes with an iPhone 4 or iPhone 4S). This sadly means that the iPhone 3GS and earlier will not be able to use the new Mobile Dashboard. This wasn't done as part of some devious plan on IBM's part to force you to buy a new iPhone, the developers simply needed the better resolution to draw those graphs and provide the richest and clearest display of information on a single page (you will believe it when you see it, the detail is quite stunning).
The Apple Store clearly states the hardware and iOS requirements on the download page, however you can still try to install it on an iPhone 3GS. Curiously what you get is this rather bizarre message:
The reason you get this message is simple: There is no way to specify when uploading a new app to Apple that you need the Retina display. So instead the developer needs to specify a feature that is not found on earlier iPhones, such as a camera flash. So it is not that the XIV Mobile Dashboard needs a flash in your camera, it is simply a quirk of the Apple store.
And for those of you who are using Android devices, your calls are being heard. Watch this space for developments in that direction.
Here are two common statement I often hear from clients:
I don't just want SAS drives, I also want SATA drives. SATA drives are cheaper than SAS drives.
Nearline SAS drives are just SATA drives with some sort of converter on them.
So is this right? Is this the actual situation?
First up, if your storage uses a SAS based controller with a SAS backplane, then normally you can plug SAS drives into that enclosure, or you can plug SATA drives into that enclosure. This is great because when you plug SATA drives into a SAS backplane, you can actually send SCSI commands to the drive plus you can send native SATA commands t00 (which is handy when you are writing software for RAID array drivers).
But (and this is a big but) what we do know is that equivalent (size and RPM) SAS drives perform better than SATA drives. This is because:
SAS is full-duplex, SATA is simplex.
SAS uses the native SCSI command set which has more functionality (which leads to the next point).
A SAS drive uses SCSI error checking and reporting which is much more robust than the SATA error reporting. This allows your storage system to collect richer information from the drive if errors are occurring (such as a failing or marginal disk).
SAS drives are dual ported which is vital in dual controller enclosures.
So given a choice (and a very small price differential), why choose SATA over SAS? SAS is the clear winner. What we should instead differentiate on is speed (7.2K RPM vs 10K RPM vs 15K RPM vs SSD) and size (2.5" vs 3.5" form factor).
Which leads us to Nearline SAS
It is a common belief, that if you buy a Nearline SAS (or NL-SAS) drive it is really a SATA drive with a SAS connector (interposer) stuck on it. But this is confusion from the past.
What led to the confusion?
Most midrange and enterprise storage controllers and enclosures up until recent years, used disks that had fibre channel interfaces on them. We plugged those disks into fibre channel enclosures. Examples include the DS4700 or the DS8100. And yet these devices also offered SATA drives. How did they do this?
They took a SATA drive and added a SATA to Fibre Channel converter card to the disk. We call this extra piece of hardware an interposer or bridge card. So people start assuming that this is common practice in every product. In fact we are now seeing SAS drives being put into fibre channel disk enclosures by using a SAS to fibre channel interposer.
There are in indeed older products that did take a SATA drive and add a SATA to SAS interposer to achieve a similar thing. But that really is not necessary any more. The reason? The same hard drive can now be ordered from the factory as either a SAS drive or a SATA drive.
Seagate have a nice selector tool to let you see all their possible combinations. For instance you can order a 2 TB drive with a 6 Gbps SAS interface, which is a model ST32000444SS:
Or you can order a 2 TB drive with a 6 Gbps SATA interface, which is a model ST2000NM0011:
So what you get is very similar drive hardware (same spindles, heads, motors) but with different adapter hardware, built with the desired adapter at manufacture time. Meaning that if we install this drive into a SAS enclosure, there is no need to add an interposer or bridge card to the drive after you bought it.
This leads to the next question:
OK. So this is good, so Nearline SAS drives are MADE as SAS drives. Does that mean a drive manufactured with a SAS adapter is a SAS drive or a Nearline SAS drive?
Now we are mixing up two different things. SAS as a standard is a combination of a connection technology (the Serial Attached part) and a command set (the SCSI part). Actually SCSI as a standard also defines both connection methods and command sets. So SAS is really talking about how we connect to the disk and what command set we use to control the disk.
Nearline on the other hand is a statement about the disks rotational speed and it's mean time between failure (MBTF). A Nearline-SAS drive is Nearline because:
It rotates slower (7200 RPM) than the higher specified Enterprise drives (that spin at 10 K or 15K RPM). Because they are slower they can also hold way more data.
It has a lower MBTF (1.2 million hours) than the higher specified Enterprise drives (which are normally specified at 1.6 million hours).
So we have now gone full circle. A Nearline-SAS drive can use the same physical disk hardware as a SATA drive, but with a superior adapter that uses a superior command set, built onto the drive at manufacture time.
Still confused or want to read some more? Check out these links: