Introduction

I recently assisted a little at a help desk. It was to validate the steps to move storage spaces from Windows 8.1 to Windows 10 workstations (DELL Precision). The engineers tend to have considerable local storage needs. Delivering to them both the capacity and performance they need, as well a choice in protection levels, was facilitated tremendously by Storage Spaces.

Ever bigger sized SSD and NVMe disks helped a lot as well. I remember way back when we built and validated a workstation configuration that had a JBOD to achieve the needed IOPS and capacity. That was very cool. Not literally (it produced quite some heat) and it was also a bit noisy. But their needs at that time required it. We have it easy now with 4TB NVMe, SSD readily available. Then again, the need ever more and faster storage. That has not changed at all.

PS: making backups is easier than ever as well and for that, I leverage Veeam Agent for Windows. You have free and paid versions and it is a great tool in our arsenal. You can have them leverage it as a DIY solution or centrally manage it from the Veeam Backup & Replication console. Whatever fits your need and budgets.

Why Storage Spaces in the first place

By leveraging storage spaces for the data volume(s) we avoid a dependency on raid controllers. The quality ones are expensive and you run the risk that when the workstation needs to be replaced you either have to move the raid controller with it (drivers, firmware and support might be an issue) or you can’t easily move between controllers when dealing with different vendors.

Move Storage Spaces from Windows 8.1 to Windows 10

Let’s take a look at the Storage Pool and the volume in the old Windows 8.1 workstation. As you can see all is well. I advise you to fix any issues before you move the disks to the new Windows 10 Workstation.

Shut down the Windows 8.1 workstation.
Remove the disks used in the storage spaces pool from the Windows 8.1 workstation.
Add these disks to the new Windows 10 workstation (no raid controller or such, Storage Spaces rules apply!).

Boot the Windows 10 workstation and log in.
Open Windows Explorer. The data on the Storage Spaces volume is already there and accessible. Smooth!

Open Storage Spaces Manager. You will see an informational block about upgrading the Storage Spaces pool to enable new features. This is recommend when you know you don’t have to move the pool back to an older OS.

Click change settings and click on Upgrade pool. You will be ask to click the button upgrade pool to confirm this. Note that when you upgrade the pool you can no longer move it back to Windows 8.1.

That’s it. As Upgrading the storage pool is fast and online. The only downtime was to physically move the disks from the old to the new workstation. As the last action, I choose to optimize drive usage when the workstations are returned to the engineer’s desk. This is new in Windows 10.

Just let it run. It has some performance impact but the engineers where too happy with a easy data move and their new workstation to complain about that.

Conclusion

Banking on storage spaces to provide some organizations their GIS and CAD engineers with a lot of local storage in their workstations has proven to be a rock solid choice. They get to have both capacity and performance which can be balanced. Large SSD disk sizes have been a great help with this. Anyway, one makes choices but ours to leverage storage spaces on the client has been a success. The migration of the disks from old workstations to new ones was easy and straightforward. It allowed us
to move storage spaces from Windows 8.1 to Windows 10 workstations easily. The portability of Storage Spaces rocks. IT Support happy, clients happy. Some of the engineers on their own or with the helpdesk are replacing disks for bigger ones or moving to SSD.

Happy New Year! Today we welcome 2019. I wish all my readers the best for 2019. May your hikes and journeys, both recreational & inspirational, lead you to beautiful places and gorgeous views to behold. Enjoy the experience, the adventure and efforts along the way to get there. Be grateful you have the abilities to do so.

As I welcome 2019, I’ll be diving into some interesting technologies, trends & strategies to investigate, discuss, implement and advise on. Join me on my journey in 2019!

Introduction

When you have upgraded your SC Series SAN to SCOS 7.3 (7.3.5.8.4 at the time of writing, see https://blog.workinghardinit.work/2018/SCX08/13/sc-series-scos-7-3/ ) you are immediately ready to start utilizing the SCOS 7.3 distributed spares feature. This is very easy and virtually transparent to do.

You will actually notice a capacity and treshhold jump in your SC array when you upgraded to 7.3. The system now know the spare capacity is now dealt with differently.

How?

After upgrading you’ll see a notification either in Storage Manager or in Unisphere Central that informs you about the following:

“Distributed spare optimizer is currently disabled. Enabling optimizer will increase long- term disk performance.”

Once you click enable you’ll be asked if you want to proceed.

When you click “OK” the optimizer is configured and will start its work. That’s a one way street. You cannot go back to classic hot spares. That is good to know but in reality, you don’t want to go back anyway.

In “Background Processes” you’ll be able to follow the progress of the initial redistribution. This goes reasonabely fast and I did 3 SANs during a workday. No one even noticed or complained about any performance issues.

The benefits are crystal clear

The benefits of SCOS 7.3 Distributed Spares are crystal clear:

• Better performance. All disks contribute to the overall IOPS. There are no disks idling while reserved as a hot spare. Depending on the number of disks in your array the number of hot spares adds up. Next up for me is to rerun my base line performance test and see if I can measure this.
• The lifetime of disks increases. On each disk, a portion is set aside as sparing capacity. This leads to an extra amount of under-provisioning. The workload on each of the drives is reduced a bit and gives the storage controller additional capacity from which to perform wear-leveling operations thus increasing the life span.
• Faster rebuilds. This is the big one. As we can now read AND write to many disks the rebuild speed increases significantly. With ever bigger disks this is something you need and what was long overdue. But it’s here! It also allows for fast redistribution when a failed disk is replaced. On top of that when a disk is marked suspect the before it fails. A copy of the data takes place to spare capacity and only when that is done is the orginal data on the failing disk taken out fo use and is the disk marked as failed for replacement. This copy operation is less costly than a rebuild.

Moving from AHCI to Raid

In the previous blog post, we moved from RAID to AHCI. Moving from AHCI to RAID can also be achieved without reinstalling Windows. With my NVME disk, I have not seen a huge performance difference between AHCI with the native Windows driver and RAID with Intel RST. If, however, you want to move back from AHCI to RAID when newer drivers become available this is also possible. Depending on your approach it can be a more tedious process with some risk, but normally you can always fall back to AHCI if it doesn’t work out and, otionally, try another approch.

You can also find a procedure to move from RAID to AHCI in https://gist.github.com/chenxiaolong/4beec93c464639a19ad82eeccc828c63. I mentioned before. Make sure you read and understand it before jumping in. Also, why try the easier ways first. Read on!

I personally have used other ways to do this. Manipulating some registry settings in combination with a safe boot before booting normally does the trick as well. This works with both SATA SSD and M.2 NVMe drives and it enables relatively fast switching between back and forth between AHCI and RAID. I have described this method below.  I have also tried the same process used to switch from RAD to AHCI and that works as well.

• Switch to safe boot
• Reboot into BIOS
• Change from AHCI to RAID in the BIOS
• Boot into safe mode
• Turn off safe mode and reboot normally again

Nothing else and that also did the trick, just like with moving from RAID to AHCI.  So the link above and my step by step below is here for completeness. You have options in case one of them doesn’t work!

Step by step AHCI to RAID registry method

This procedure I describe below works on Windows 10 1803/1809 and has been tested on Dell Latitude E6220 an XPS 13 9360. Editing the registry is always a little risky if you have no clue what you are doing. So, beware if you mess up and can’t figure out how to get out of this pickle, you might need to redeploy/restore from backup.

To change the SATA operation mode from AHCI to RAID follow the steps below.

Prepping the registry settings

• Open the registry editor regedit
• Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSetXXX\Services\and find the some of the keys that are below (not all will exist depending on your laptop’s configuration):
  • iaStor: (Intel RAID, 3 = off, 0 = on).
  • iaStorAVC: (Intel Chipset SATA RAID Controller,3 = off, 0 = on).
  • iaStorAV: (Intel(R) SATA RAID Controller Windows,3 = off, 0 = on).
  • iaStorV:(Intel RAID Controller Windows 7, 3 = off, 0 = on)
  • storAHCI: (this is AHCI, 3 = off, 0 = on)

You can put all these to 0 if you want, that doesn’t matter but normally you’ll know which one matters. AHCI is easy, there is only one entry. For the iaStor options I know I need aiStorAVC as the one I see in device manager and in the WinDbg MEMORY.DMP analysis is iaStorAVC.sys in my previous blog post.

When you find a StartUpOverride sub key and it is set to 3 also change this to 0 for the value you want to switch to.

Just make sure you set the one you need to 0 as then it will be picked up when you switch between AHCI/RAID in the BIOS. If you’re in you can set them all to 0 as the setting in the BIOS will pick up the correct one and windows will reset the StartupOverride value where needed.

When changing values in CurrentControl001 or 002 make sure you know the one that is being used. You can find that inHKEY_LOCAL_MACHINE\SYSTEM\Select in the value named Current. If it is 1 edit CurrentControl001 if its 2 edit CurrentControl002 (that key might not even exist).

Making sure you go into safeboot mode

• After changing the registry setting set the default boot mode to Safe Mode, use msconfig.exe or open an admin cmd/PowerShell window and run: bcdedit/set ‘{current}’ safeboot minimal
• Reboot and hit F2 to enter the BIOS.
• Change the SATA mode to RAID.
• Save and reboot.
• After Windows successfully boots into Safe Mode, disable Safe Mode with msconfig.exe or open an admin cmd/PowerShell window and run: bcdedit /deletevalue ‘{current}’safeboot
• Reboot again.
• Log in and verify in Device Manager, that you now have the Intel Chipset SATA RAID Controller device under Storage Controllers.

Updating the Intel RST driver

• You are now back to RAID but are still at the driver level that is causing your BSODs. Mine was 15.9.
• To fix that you need to upgrade your Intel RST driver. While doing so you might get a warning about being unable to inject the driver into the recovery partition but you can ignore this and take care of that later.

• Now reboot again and check the storage controller now in device manager. You’ll find an Intel Chipset SATA/PCIe RST Premium Controller now with driver version 16.7.0.1009 at the time of writing and that is the one I used and which fixed the BSODs for me when using RAID. Now DELL also releases updates on their support site you can try. If that doesn’t fix it, grab a more recent one from Intel if you can find one to try. That is what I did here.

• The old AHCI disk is still visible when you enable show hidden devices but also shows the disk name as know to the Intel Chipset SATA/PCIe RST Premium Controller.

Important

Note that if you have a BSOD during the installation don’t despair, try again and after a successful run and reboot you’ll have the new driver. Then you’ll have to work on the laptop and see if it still blue screens. If so, revert back to AHCI.

I hope this helps someone out there, including my future self.