Change Storage Controller from SATA to SAS

[ZAJDAN]

Hello,
I would like to change my current SATA Controller to SAS. The virtual machine which is attached to the Controller is Windows Server 2008 R2.
What I made:
1) Added to the virtual machine SAS Controller and attached there 1GB test_SAS.vdi
2) boot machine -> Windows successfully installed driver for SAS Controller
3) shutdown machine and system boot disk I have attached to the SAS Controller and removed the SATA.

The problem is that Windows can not boot.

Thank You for any hint
Regards ZAJDAN

[Selin]

Did you kept the disk order number?
What error guest displays when stops?

[socratis]

Just FYI, I tried it with a Win7 guest, which is the closest to Win2008r2, and it worked just fine.

But, out of curiosity, why would you want that change?

[ZAJDAN]

But, out of curiosity, why would you want that change?

because WindowsServer File Services crying, that can not enable disk cache, and mainly because of speed.

[ZAJDAN]

Did you kept the disk order number?
What error guest displays when stops?

you mean order in settings of VirtualBox?
FATAL: INT18: BOOT FAILURE

[Selin]

Just to doublecheck: did you removed/detached test_SAS.vdi?
Just to be sure the system didn't try to start from that disk.
You can try to fix it with Startup Repair tool (boot from original MS Windows DVD ISO and select Repair option).

And in addition - it looks like you are not a new with this error.
For example - viewtopic.php?f=6&t=73947

[Selin]

Just checked with Windows 2016 - all ok.
1. add SAS controller with CD drive to guest
2. start the guest to install new controller drivers
3. shutdown the guest
4. remove SATA controller from the guest with all drives attached
5. attach all drives to the SAS controller
6. restore drives order to make sure system disk is the first one (i.e. attached to port 0)
7. start the guest
Profit!

[socratis]

I did a slightly modified step-by-step procedure, I'll include it just for completion:

1. Add SAS controller to guest.
2. Start the guest to install new controller drivers.
3. Verify in the Device Manager (in the guest) that the controller is up and running.
4. Shutdown the guest, release the VDI from the SATA controller, add the same VDI to the SAS controller.
5. Reboot the guest, make sure it works.
6. Shutdown and remove the SATA controller.

I did *not* profit from this. Maybe I'm doing something wrong, can anyone help? I have all the IBAN numbers available if anyone wants to debug this...

[Selin]

I did *not* profit from this. Maybe I'm doing something wrong, can anyone help? I have all the IBAN numbers available if anyone wants to debug this...

Maybe it depends on host configuration and/or guest system.
In my case migrating from SATA to SAS increases disk readingup to 30% (Windows 2018 R2 and Windows 2016).
Maybe it depends on system drivers for the specific (virtual) hardware.

The same as for the network adapter: with Intel Server NIC I have much faster LAN speed (guest-guest) than with VirtIO NIC - 90..100MBps vs 70..80MBps.

[socratis]

When I said "profit" and "IBAN" followed by a big smile, I thought it would be obvious it was a joke...

In my case migrating from SATA to SAS increases disk readingup to 30%

Profit 30% if you switch controllers? I doubt it, I highly doubt it. I could see potentially some benefits from IDE to SCSI/SATA and that's because of the serialized calls, but where the bottleneck is (on your host, the physical access), that part doesn't change that much. In fact, it doesn't change at all. So, I'm not quite sure where that 30% came from...

The same as for the network adapter: with Intel Server NIC I have much faster LAN speed (guest-guest) than with VirtIO NIC

Hmm... That seems to contradict the expectations of the developers, see User Manual ch. 6.11. Improving network performance.

[Selin]

... but where the bottleneck is (on your host, the physical access), that part doesn't change that much.

With SAS I almost have full host speed while SATA gives much slower read speed.

In fact, it doesn't change at all. So, I'm not quite sure where that 30% came from...

So am I.
Again - my assumtion is in guest drivers used for virtual devices.

...with Intel Server NIC I have much faster LAN speed (guest-guest) than with VirtIO NIC

Hmm... That seems to contradict the expectations of the developers, see User Manual ch. 6.11. Improving network performance.

I've read that and started with virt-io, but got bandwidth lower than expectations.
Then I've tried to switch to Intel MT Server NIC and got much higher result.
Maybe this is specific for OSE version of VirtualBox... I don't know. I'm rather sysadmin than developer.
I've met the similar result here: http://empt1e.blogspot.ru/2016/11/bhyve ... part2.html