Max Limit =30 SATA disks in VirtualBox

[paolfili]

Hello.
Adding disk to SATA controller after 30 disks there is no more possibility to add disks.
IDE allow only 2 more disks.
Is possible to change the 30 disks limit for SATA controller?
Thanks

Paolo

[mpack]

I doubt it, considering that 15 devices per channel seems to be the official limit for SATA. There are probably protocol reasons why this can't be exceeded even if you ignored the SATA standards (e.g. a limit like that usually means a 4 bit address field, with 0000 being reserved for broadcasts/replies/master etc).

Add another SATA controller?

[paolfili]

Thanks for the reply mpack
I' m using 4.2.10.
I' ve tried to add a controller.(Using the +icon at the bottom of Storage tab) But I' n not able to add more than 1 SATA and 1 IDE controller.
Googling does not help for this issue.
Can you help me?
Thanks

paolo

[mpack]

I don't see how I can help you. It looks like you are correct that only one SATA controller is allowed (something I didn't know). So, if that's the limit then that is the limit.

I see that a SCSI controller can still be added, though that may require additional drivers in the guest.

[Rootman]

We're all dying to know, just WHY do you need more than 30 disks? I'm king of needing weird stuff and just curious as to why you need it.

[noteirak]

We're all dying to know, just WHY do you need more than 30 disks? I'm king of needing weird stuff and just curious as to why you need it.

We all tried to avoid the huge elephant in the room! What have you done!

[Rootman]

We all tried to avoid the huge elephant in the room! What have you done!

What can I say, I'm a glutton for punishment

[mpack]

I think it's also worth noting that guest Operating Systems may also have limits on the number of disk devices which can be attached. E.g. I have no idea what happens when Windows exhausts the range of 26 possible drive letters? OS's will generally list such things in tables, and the tables will have a finite number of entries.

[aeichner]

You can add more SATA controllers if you change the chipset of the VM to ICH9 instead of PIIX. ICH9 includes some PCI to PCI bridges which allow more PCI devices assigned to the VM.

[paolfili]

Thanks everyone for the reply.
I need to add more than 30 disks becouse I' ve undersized some high_redundancy oracle diskgroups.(a lot of work to transport DN on resized diskgroups)
There is probably a limit at OS level.(Oracle Linux) as suggested from mpack, but the solution for me was the aeichner tips.
Thanks anyway to all.

Paolo

[mpack]

I have no idea what happens when Windows exhausts the range of 26 possible drive letters

And to answer my own question: the solution is NTFS junction points, though of course this assumes that you have an NTFS volume available.

[martyscholes]

We're all dying to know, just WHY do you need more than 30 disks? I'm king of needing weird stuff and just curious as to why you need it.

For what it's worth, I have 68 physical spindles on my personal server: 2 SAS and 66 fibre, although my wife is not amused by our power bill.

As paolfili noted, once you get into redundancy, very large spindle counts seem reasonable, if not necessary. Small (300GB) disks are cheap. Lots of disks under ZFS gives you fine-grained control of iops, throughput, redundancy and capacity. For the geek in me, seeing six 11-disk arrays in a rack is just cool.