IBM SAN Volume Controller (SVC) has offered Fibre Channel Storage Virtualization since June 2003. Two SVC nodes communicate with each other via fibre channel to form a high availability I/O group. They then communicate with the storage that they virtualize via Fibre Channel and with the hosts they serve that virtual storage to, via Fibre Channel. When IBM added real-time (metro mirror) and near real-time (global mirror) replication it was also done using Fibre Channel, with each SVC cluster communicating to the other by connecting using fibre channel protocol transported over dark fibre with or without a WDM or via FCIP (Fibre Channel over IP) routers.
Each Fibre Channel port on an SVC node can be a SCSI initiator to backend storage, a SCSI target to hosts and all the time communicate to its peer nodes using those same ports. With every generation of SVC node, these ports got faster and faster, going from 2 Gbps to 4 Gbps to 8 Gbps. In SVC firmware V5.1 IBM added iSCSI capability to the SVC using the two 1 Gbps ethernet ports in each node. This allowed each node to also be an iSCSI target to LAN attached hosts.
When the Storwize V7000 came out in Oct 2010 it offered all of this capability, plus offered two fundamental changes to the design.
- Firstly the two controllers in a Storwize V7000 can communicate with each other across an internal bus, eliminating the need to zone them together (or even attach the Storwize V7000 to Fibre Channel fabrics).
- The other more obvious difference is that a Storwize V7000 comes with its own disks, which it communicates with via multi-lane 6 Gbps SAS.
When IBM added 10 Gbps Converged Enhanced Ethernet adapters to the SVC and to the Storwize V7000, these adapters operated as iSCSI Targets, allowing clients to access their volumes via a high-speed iSCSI network. In V6.4 code IBM allowed these adapters to also be used for FCoE (Fibre Channel over Ethernet). These are also effectively SCSI targets ports allowing hosts that use CEE adapters to connect to the SVC or V7000 over a converged network.
If you have a look at the Configuration limits page for SVC and Storwize V7000 version 6.4 (the Storwize V7000 one is here), you will see this interesting comment:
"Partnerships between systems, for Metro Mirror or Global Mirror replication, do not require Fibre Channel SAN connectivity and can be supported using only FCoE if desired"
So does this mean we can stop using FCIP routers to achieve near real-time replication between SVC clusters or Storwize V7000s? The short answer is most likely not. Lets look at why...
The whole reason Fibre Channel became the standard method to interconnect Enterprise Storage to Enterprise hosts is simple: Packet loss is prevented by buffer credit flow control. Frames are not allowed to enter a Fibre Channel network unless there are buffers in the system to hold them. Frames are normally only dropped if there is no destination to accept them. Fibre channel is a highly reliable, scalable and mature architecture. When we extend Fibre Channel over a WAN we do not want to lose this reliable nature, so we use FCIP routers like Brocade 7800s, that continues to ensure frames are reliably delivered in order, from one end point to another.
Converged enhanced ethernet allows Fibre Channel to be transported inside enhanced ethernet frames. The one fundamental that CEE brings to the table is the same principle that a frame should not enter the network without a buffer to hold it. Extending FCoE over distance has the same challenge: the moment you start moving those frames over a WAN connection you need to ensure frames are not lost due to congestion. How do we do this? The same way we did with Fibre Channel: we use Dark Fibre, we use WDMs or we use routers. The same issues and requirements exist.
For more information on FCoE over distance check out this fantastic Q&A from Cisco:
If you want to understand FCoE better, this document from Brocade is very good:
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.
The IBM download site is here:
For SRM 4.0 with a Storwize V7000 or SVC on V6.3 you can use:
For SRM 5.0 with a Storwize V7000 or SVC on V6.3 you can use:
For both links please check the FTP site to see if there is a later version.
Please also keep checking the VMware support matrix for the official support statement. I can see at least one example of someone using the latest SRA here.
It is ironic that only days after I wrote that 497 is the IT number of the beast, I learn that Linux has another unfortunate number: 208.
The reason for this is a defect in the internal Linux kernel used in recent firmware levels of SVC, Storwize V7000 and Storwize V7000 Unified nodes. This defect will cause each node to reboot after 208 days of uptime. This issue exists in unfixed versions of the 6.2 and 6.3 level of firmware, so a large number of users are going to need to take some action on this (except those who are still on a 4.x, 5.x, 6.0 or 6.1 release). If you have done a code update after June 2011, then you are probably affected. This means that if you are an IBM client you need to read this alert now and determine how far you are into that 208 day period. If you are an IBMer or an IBM Business Partner, you need to make sure your clients are aware of this issue, though hopefully they have signed up for IBM My Notifications and have already been notified by e-mail.
In short what needs to happen is that you must:
- Determine your current firmware level.
- Check the table in the alert to determine if you are affected at all, and if so, how far you are potentially into the 208 day period.
- Use the Software Upgrade Test Utility to confirm your actual uptime.
- Prior to the 208 day period finishing, either reboot your nodes (one at a time, with a decent interval between them) or install a fixed level of software (as detailed in the alert).
To give you an example of the process, my lab machine is on software version 126.96.36.199 which you can see in the screen capture below. So when I check the table in the alert, I see that version 188.8.131.52 was made available on January 24, 2012, which means the 208 day period cannot possibly end before August 19, 2012.
|Version Number||Release Date||Earliest possible date that a system running this release could hit the 208 day reboot.|
SAN Volume Controller and Storwize V7000 Version 6.3
|184.108.40.206||30 November 2011||25 June 2012|
|220.127.116.11||24 January 2012||19 August 2012|
Regardless, I need to know the uptime of my nodes, so I download the Software Upgrade Test Utility (in case you have an older copy, we need at least version 7.9) and run it using the Upgrade Wizard (NOTE! We are NOT updating anything here, just checking):
I Launch the Upgrade Wizard, use it to upload the tool and follow the prompts to run it, so that I get to see the output of that tool. The output in this example shows the uptime of each node is 56 days, so I have a maximum of 152 days remaining before I have to take any action. At this point I select Cancel. You can run this tool as often as you like to keep checking uptime.
Note if you are on 6.1 or 6.2 code you may see a timeout error when running the tool, especially for the first time. If you do see an error, please follow the instructions in the section titled "When running the the upgrade test utility v7.5 or later on Storwize V7000 v6.1 or v6.2" at the Test Utility download site.
As per the Alert:
- If you are running a 6.0 or 6.1 level of firmware, you are not affected.
- If you are running a 6.2 level of firmware, the fix level is v18.104.22.168 which is available here for Storwize V7000 and here for SVC.
- If you are running a 6.3 level of firmware, the fix level is v22.214.171.124 which is available here for Storwize V7000 and here for SVC.
- If you are using a Storwize V7000 Unified, the fix level is v126.96.36.199 which is available here.
You should keep checking the alert to find out any new details as they come to hand. If you are curious about Linux and 208 day bugs, try this Google search.
*** Updated April 4, 2012 with links to fix levels ***
If you have any questions or need help, please reach out to your IBM support team or leave me a comment or a tweet.
*** April 10: The IBM Web Alert has been updated with new information on what to do if your uptime has actually gone past 208 days without a reboot. In short you still need to take action. Please read the updated alert and follow the instructions given there. ***
I always laugh when people say to me: I wouldn't know what to blog about!
When you work in pre-sales support, you constantly get asked questions and each one of them could be the subject of a new blog post. Right now the most common question I am getting is:
I am implementing VMware Site Recovery Manager (SRM). One of the components I need are vendor specific Site Recovery Agents (SRA). I have searched IBM's website but cannot find them. Where are they?
So the short answer is: you get them from the VMware SRM download site.
However before downloading, there is a key task that absolutely needs to be performed:
- Visit the VMware vCenter Site Recovery Manager Storage Partner Compatibility Matrix. This site will confirm what products are supported by each version of SRM. You can find it here, but clearly you need to check back regularly to ensure you have the latest information.
- Now find your storage device in the matrix and confirm what firmware levels are supported. This is really important. For example, the Feb 27, 2012 edition of the matrix tells me that the Storwize V7000 is supported for SRM version 5.0, but only when running Storwize V7000 firmware version 6.1 or 6.2. This is significant because if you upgrade to version 6.3 you are not supported. In fact that combination doesn't actually work yet, as detailed here. Clearly something you need to be aware of when planning firmware updates.
So where are the SRAs? On each of the pages below use the Show Details button to see what version SRAs are being shipped with that SRM (although sometimes the pages take a few days between an SRA being added and the page being updated):
VMware vCenter Site Recovery Manager 4.1.2
VMware vCenter Site Recovery Manager 5.0
There are a few more questions I routinely get asked:
Does IBM actually have an SRA download site?
The answer is yes, but it is an FTP site only for SRAs written by IBM. It is principally a repository for older SRAs and beta SRAs but you can also find the current SRAs on it. You can find the site here. Note however that it is NOT the official source. For that you need to use the VMware site.
What about the SRA for LSI/Engenio based products like the DS4800?
These used to also be found on the LSI site, but since LSI sold Engenio to NetApp, it is no longer available from the LSI or NetApp websites. You need to download the current version from the VMware sites listed above. There is a version for SRM 5 on the VMware download site.
What about nSeries SRAs?
If you need an nSeries SRA, again you should go to the VMware download pages. There are separate SRAs listed and available for IBM nSeries (as opposed to an SRA for NetApp branded filers).
What about an SRA for XIV with SRM version 5?
The answer: The SRA for XIV with SRM 5 (and 5.0.1) is now available from VMware. If you have access to download SRM, you will be able to download SRA version 2.1.0. It is the same SRA for both XIV Generation2 and Gen3.
What about an SRA for Storwize V7000 and SVC version 6.3 code?
The answer: It is coming. We are working to make it available as soon as possible. I will update this post as soon as I have a date for you (we are talking weeks, not months).
*** Update March 23, 2012 - Added details on SRM 5.0.1 ***
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:
Password status: 
Password status:  IBM_2076:StorwizeV7000_324:anthonyv>setpwdreset -h
I then try to reset the password with the USB key, but I get a very different message when I run the init-tool after moving the USB key back to my laptop:
If I then change my mind, I can enable password reset via this command:
So do I recommend you do this on your machine?
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:
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.
Lets look at an example. If you head over to the Seagate website and look at one of their ranges of 3.5" Enterprise Drives, you should hopefully make it to this URL:
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:
I love USB keys, I love free ones, conferences give away ones and ones shaped like lego blocks. The exciting thing (for me) is that if you buy a Storwize V7000, you also get a USB key: A key which has two fundamental purposes:
- It's used to make installation very quick and easy (which it does very well!).
- It's used to reset the superuser password (in case you forget what it is) or to set the service IP addresses (in case you didn't set them like I suggested you do ).
This is all well and good but what happens when you lose it, borrow it or accidentally throw it out? (oops) If you are searching for it, yours may well have looked like this:
So what to do? The answer is: It's OK, there is nothing magic about this key. In fact the key contains just one piece of software, which you can get from here. Just download the initialization tool and copy it onto your own USB key. The original key also had an Autorun file, but you don't need that (actually I object to auto-running USB keys anyway).
BUT... and there is always a but... I cannot guarantee that EVERY USB key you try will work. Why not? Because some USB keys are formatted strangely or insist on running unique applications before they will work. There is some good, simple advice on the InfoCenter that you can find here. The main trick is to use a USB key that is formatted with the FAT32, EXT2, or EXT3 file system on its first partition and does not need to auto-run any applications before working.
The IBM SVC has has been setting records in SPC-1 (OLTP-like) benchmarks for many years. However recently HP stole the crown with a 3Par benchmark of 450,212.66 IOPS.
But in breaking news, the SVC is back on top with the very first SPC benchmark that exceeded 500,000 IOPS (520,043.99 to be precise!). You can see the executive summary here.
This benchmark used eight of the current SVC engines (model CG8s) with Storwize V7000 as the backend disk. It shows the awesome power of SVC, its ability to scale and to handle very large configurations with very large throughput requirements. It also shows the power of IBM pSeries which was used to drive these IOPS.
The full disclosure report is here.
The first update for Storwize V7000 and SVC release 6.3 is now available. You will find it here for Storwize V7000 and here for SVC (note both links will require you to login to Fix Central with your IBM ID). As usual the new release contains a combination of new features and fixes. The new features are:
New features in SVC 188.8.131.52
* Support for multi-session iSCSI host attachment
* Language Support for Brazilian Portuguese, French, German, Italian, Japanese, Korean, Spanish, Turkish, Simplified Chinese and Traditional Chinese
There are also several fixes (with some variation between SVC and Storwize V7000, mainly around the platform hardware). The release notes (which you can find at the links above) detail them all. Two fixes I have been looking forward to are:
IC80253 Unable to log into the GUI if password contains special characters.
This meant that a password with a comma in it could not be used in the GUI (you got a backspace instead). Passwords with commas could be used in the CLI. This bug was picked up by one of my clients when trying out LDAP and is now fixed in 184.108.40.206.
IC80501 Performance statistics collection fails to record read and write response times for internal drives.
This issue meant that SVC internal SSD drives always showed 0 ms response times in TPC.
Note that the Drive firmware does not need to be updated with this release. The new upgrade test tool (version 7.3) will not ask you to update them. I will let you know when that situation changes.
With the announcement of 900GB 10K RPM drives for the Storwize V7000, the range of possible drives you can order is now even more outstanding.
In the 2.5" form factor IBM has the following 10K RPM drives:
Feature 3203 300GB 2.5 inch. 10k SAS HDD
Feature 3204 450GB 2.5 inch. 10k SAS HDD
Feature 3206 600GB 2.5 inch. 10k SAS HDD
Feature 3509 900GB 2.5 inch. 10k SAS HDD <-- NEW!
In the 2.5" form factor IBM also has the following 15K RPM drives:
Feature 3251 146GB 2.5 inch. 15k SAS HDD
Feature 3253 300GB 2.5-inch. 15K SAS HDD
In the 2.5" form factor IBM also has the following Solid State Drives:
Feature 3512 200GB 2.5-inch. SAS E-MLC SSD
Feature 3504 300GB 2.5 inch. SAS E-MLC SSD
Feature 3514 400GB 2.5-inch. SAS E-MLC SSD
In the 2.5" form factor IBM also has the following 7.2K RPM nearline-SAS drive:
Feature 3271 1 TB 2.5-inch 7.2k Nearline-SAS HDD
In the 3.5" form factor IBM also has the following 7.2K RPM nearline-SAS drives:
Feature 3302 2TB 3.5 inch. 7.2k Nearline-SAS HDD
Feature 3303 3TB 3.5 inch. 7.2k Nearline-SAS HDD
The big question of course is which drive type to choose? The answer is that ideally you should possess three pieces of information:
- How much usable space do you need in GB or TiB? Don't confuse binary and decimal!
- What is your typical I/O profile. For instance 70% reads 30% writes, 32KB block size.
- What are your IOPS and response time requirements?
Armed with this information, get your IBM Sales Rep or Business Partner to model your requirements using Capacity Magic and Disk Magic. These modelling tools will tell you how much usable capacity a particular configuration will give you and what performance you can expect to get from it (given a particular I/O profile). If you don't know your I/O profile or IOPS requirements, you can still see performance modeling using industry standard benchmarks.
I am getting this question on a very regular basis:
"We have just upgraded to ESXi 5.0 but we cannot find the VAAI driver on the IBM Website"
The answer? There is no vendor supplied driver because no driver is needed. ESXi 5.0 uses a SCSI T10 compliant set of commands that all vendors need to support for VAAI to work.
But of course in the tradition of all answered questions, it leads to another question:
"Once I have upgraded to ESXi 5.0 how can I tell if VAAI is really working?"
The good news is that it is very easy to spot if ESXi 5.0 has detected a VAAI capable LUN. The moment a new LUN is detected by ESXi 5.0 it tries out an Atomic Test and Set command. If that works, you will see that Hardware Acceleration shows as Supported in vCenter. In the screen capture below I have three datastores, two from XIV and one from Storwize V7000, all presented to an ESXi 5.0 server. I dragged the Hardware Acceleration column over from the right hand side to help with the screen capture (in case your vCenter looks different), but you can see the Hardware Acceleration column shows each DataStore as Supported (and did so the moment the volume was detected).
Of course having seen the Hardware Acceleration Supported message only proves that Atomic Test and Set works. To confirm if XCopy (Hardware Accelerated Move) is working, on SVC or Storwize V7000 we can use the Performance monitoring panel. In the example below I first performed a storage vMotion, moving a virtual machine between two Datastores located on the same Storwize V7000 (running 220.127.116.11 firmware). I then performed a clone of the same virtual machine, where the source was on one datastore and the target was placed on another (but both located on the same Storwize V7000). What you can clearly see is that both operations (storage vMotion and cloning) generated no volume traffic, only MDisk traffic. This means that the ESXi server is doing none of the work and the storage is doing all of the work.
For more examples of how to test VAAI, check out section 9.5.5 Testing VAAI, in the new XIV IBM Redbook draft, XIV Storage System: Host Attachment and Interoperabilty which you can find here:
It documents the following tests:
- Test one: Hardware accelerated Initialization or block zeroing
- Test two: Hardware accelerated move or full copy
The tests can be performed regardless of whether you have an XIV (on code levels 10.2.4a and above) or a Storwize V7000/SVC (on code levels 18.104.22.168 and above).
If upgrading to ESXi 5.0 with IBM Storage, please also be aware of the following knowledge base articles regarding VAAI support with IBM Storage:
XCOPY and XIV:
VAAI unmap with XIV, SVC and Storwize V7000:
The Storwize V7000 and SVC have a command line interface that you access via SSH. Every-time you logon, whether it is to transfer a file (using a tool like pscp), issue a single shot command from a script (using a tool like plink) or logon to issue commands interactively (using a tool like PuTTY), you clearly need to authenticate yourself. Since June 2003, the way you did this was to use a public/private key pair, where the SVC or Storwize V7000 had the public key and the SSH client (such as PuTTY) authenticated using the private key (the PPK file).
However with release 6.3 of the SVC and Storwize V7000 firmware, the use of key files is now optional. A user can now authenticate purely by using a password. This includes using your domain ID. So if you defined LDAP to your machine, as I documented here, you could now SSH direct to your Storwize V7000 or SVC, use your Domain user id and password and not go through the key file setup task. Nice!
The choice to continue to authenticate just with an SSH key remains available. If a user has both a password and a configured key file, then either method will work (you only need to use one - not both). Existing scripts will be unaffected by this change, so nothing gets broken because of this.
I think this is a very positive change and one I openly welcome. Combined with LDAP, this really makes user account setup an easy and simple task.