Limit number of drives scanned simultaneously?

[bitfidelity]

Is there a way to force the software to scan no more than a single drive when automatic scanning is enabled?

[Christopher (Drashna)]

Yes and no.

Specifically, by default, StableBit Scanner will only scan one drive per controller.  And in fact, you have to get into the advanced configuration to increase that.

So if you're seeing multiple drives being scanned at once, it's likely because they are connected to different controllers (you can verify this by selecting the "group by controllers" option in the UI.  

[JWhitton]

I have a TerraMaster 4 bay direct attached storage unit connected by a single USB cable. Unfortunately, Scanner reports each drive as a separate controller; is there any way to get Scanner to only scan one drive at a time?

[blaineeasy]

On 1/3/2023 at 4:36 AM, JWhitton said:

I have a TerraMaster 4 bay direct attached storage unit connected by a single USB cable. Unfortunately, Scanner reports each drive as a separate controller; is there any way to get Scanner to only scan one drive at a time?

@Christopher (Drashna)i am having the same issue as JWhitton here - I have a 4 bay device that connects with a single USB-C cable that is being seen as multiple controllers, but if i disable scanning on all drives but 1, i'm getting 40-50 mbps scanning speeds... if the disks are scanned simultaneously, i get llke 8-10mbps per disk.  Would prefer to have it stick to a single disk, otherwise it will take forever to get to 100% scanned on each disk.

[sfullam]

On 5/9/2023 at 9:08 AM, blaineeasy said:

@Christopher (Drashna)i am having the same issue as JWhitton here - I have a 4 bay device that connects with a single USB-C cable that is being seen as multiple controllers, but if i disable scanning on all drives but 1, i'm getting 40-50 mbps scanning speeds... if the disks are scanned simultaneously, i get llke 8-10mbps per disk.  Would prefer to have it stick to a single disk, otherwise it will take forever to get to 100% scanned on each disk.

@Christopher (Drashna) I also have the same issue, with a Sabrent 10-bay device, connected over USB-C. All drives are being scanned at the same time, and I'm getting 3 dropping from the pool during the scan.

Weird part is, checking the controller view, 4 are on separate "USB Attached SCSI (UAS) Mass Storage Device" while 3 are on the same "AMD USB 3.10 eXtensible Host Controller 1.20 (Microsoft)" controller. And 3 are not visible on the pool anymore - power cycling those bays or resetting the computer would probably make them visible again though. 

Is there any way to force only a single disk to be scanned at one time, regardless of number of controllers?  A global setting for 'cap max concurrent scans to 1 disk' might solve this issue with multiplexed USB enclosures.

 

[JasonC]

It doesn't look like there was any changes in the current version based on this, but I'm also running into this.

The issue here is partly because of how Windows presents USB disks. It either looks like the USB interface is the controller, or for UAS capable devices, it looks like there is essentially a UAS virtual controller that acts as a SCSI interface shim to those devices. But it looks like a single controller as well. Neither case actually really represents the physical situation (in my case, I have 2 USB enclosures with backplanes).

What would be nice and might work if we could set the scan to work on a "per assigned enclosure" level. But even that isn't quite ideal, as it wouldn't be too difficult to saturate the USB controller. That's assuming too that you are able to get a full USB 3.1 connection too. I know in my situation, I'm a bit limited on the disk interface side of things at the moment due to still having some older SATA I disks, which limits all the devices on the backplane to SATA I. Until I finish rotating those all out, I won't be able to utilize SATA III speeds, so the USB interface speed isn't even a concern, but the number of simultaneous scans still is. Actually, it's more so in my case, as I don't really have any excess bandwidth available.

 

 

[Christopher (Drashna)]

As above, by default, StableBit Scanner should only be scanning 1 disk per controller.   This can only be changed by getting into the advanced settings.

You can see how StableBit scanner sees the controllers by right clicking the column header in the UI and selecting "By Controller".   

If you do this, do you see all of these disks on different controllers, or on one controller?