Back to bug 1040714

Who When What Removed Added
Tahlia Richardson 2013-12-12 00:32:37 UTC CC trichard
RHEL Program Management 2013-12-12 18:04:41 UTC Keywords Documentation
Laura Novich 2014-03-30 08:16:32 UTC Status NEW ASSIGNED
CC lnovich
Gerd Hoffmann 2014-03-31 10:36:05 UTC CC lersek
Doc Text Cause:
SeaBIOS runs in real mode for compatibility with BIOS interfaces. This limits the amount of memory available.

Consequence:
The number of disks SeaBIOS is able to handle is limited.
Supported disk counts are:

virtio-scsi: 64
virtio-blk: 4
ahci/sata: 24 (4 controllers with all
6 ports hooked up).
usb-storage: 4 (should be enough for all practical
purposes, usb isn't the interface
you want use for lots of disks anyway).

Workaround (if any):
When attaching many disks to your virtual machine make,
sure that your system disk gets a small pci slot number,
so SeaBIOS will see it first when scanning the pci bus.

It is also recommended to use virtio-scsi instead of virtio-blk as the per-disk memory overhead is smaller.

Result:
[ ??? ]
Doc Type Bug Fix Known Issue
Flags needinfo?(lersek)
Laszlo Ersek 2014-03-31 10:50:07 UTC Doc Text Cause:
SeaBIOS runs in real mode for compatibility with BIOS interfaces. This limits the amount of memory available.

Consequence:
The number of disks SeaBIOS is able to handle is limited.
Supported disk counts are:

virtio-scsi: 64
virtio-blk: 4
ahci/sata: 24 (4 controllers with all
6 ports hooked up).
usb-storage: 4 (should be enough for all practical
purposes, usb isn't the interface
you want use for lots of disks anyway).

Workaround (if any):
When attaching many disks to your virtual machine make,
sure that your system disk gets a small pci slot number,
so SeaBIOS will see it first when scanning the pci bus.

It is also recommended to use virtio-scsi instead of virtio-blk as the per-disk memory overhead is smaller.

Result:
[ ??? ]
Cause:
SeaBIOS runs in real mode for compatibility with BIOS interfaces. This limits the amount of memory available.

Consequence:
The number of disks SeaBIOS is able to handle is limited.
Supported disk counts are:

virtio-scsi: 64
virtio-blk: 4
ahci/sata: 24 (4 controllers with all
6 ports hooked up).
usb-storage: 4 (should be enough for all practical
purposes, usb isn't the interface
you want use for lots of disks anyway).

Workaround (if any):
When attaching many disks to your virtual machine, make
sure that your system disk gets a small pci slot number,
so SeaBIOS will see it first when scanning the pci bus.

It is also recommended to use virtio-scsi instead of virtio-blk as the per-disk memory overhead is smaller.

Result:
[ ??? ]
Flags needinfo?(lersek)
Yoana Ruseva 2014-06-06 14:53:37 UTC CC yruseva
Doc Text Cause:
SeaBIOS runs in real mode for compatibility with BIOS interfaces. This limits the amount of memory available.

Consequence:
The number of disks SeaBIOS is able to handle is limited.
Supported disk counts are:

virtio-scsi: 64
virtio-blk: 4
ahci/sata: 24 (4 controllers with all
6 ports hooked up).
usb-storage: 4 (should be enough for all practical
purposes, usb isn't the interface
you want use for lots of disks anyway).

Workaround (if any):
When attaching many disks to your virtual machine, make
sure that your system disk gets a small pci slot number,
so SeaBIOS will see it first when scanning the pci bus.

It is also recommended to use virtio-scsi instead of virtio-blk as the per-disk memory overhead is smaller.

Result:
[ ??? ]
The SeaBIOS application runs in real mode for compatibility with BIOS interfaces. This limits the amount of memory available. As a consequence, SeaBIOS is only able to handle a limited number of disks. Currently, the supported number of disks is:

virtio-scsi — 64
virtio-blk — 4
ahci/sata — 24 (4 controllers with all 6 ports connected)
usb-storage — 4

As a workaround for this problem, when attaching a large number of disks to your virtual machine, make sure that your system disk has a small pci slot number, so SeaBIOS sees it first when scanning the pci bus. It is also recommended to use the virtio-scsi device instead of virtio-blk as the per-disk memory overhead is smaller.
Dayle Parker 2014-10-21 06:54:18 UTC Keywords Triaged
Flags needinfo?(kraxel) needinfo?(lersek)
Gerd Hoffmann 2014-10-21 09:25:40 UTC Flags needinfo?(kraxel) needinfo?(lersek)
Dayle Parker 2014-10-24 00:26:43 UTC Assignee lnovich virt-docs
John Skeoch 2014-12-15 00:56:45 UTC CC rhod knoel
Dayle Parker 2015-01-12 03:18:42 UTC Assignee virt-docs cboyle
Charlie 2015-02-11 23:37:45 UTC Status ASSIGNED ON_QA
Doc Text The SeaBIOS application runs in real mode for compatibility with BIOS interfaces. This limits the amount of memory available. As a consequence, SeaBIOS is only able to handle a limited number of disks. Currently, the supported number of disks is:

virtio-scsi — 64
virtio-blk — 4
ahci/sata — 24 (4 controllers with all 6 ports connected)
usb-storage — 4

As a workaround for this problem, when attaching a large number of disks to your virtual machine, make sure that your system disk has a small pci slot number, so SeaBIOS sees it first when scanning the pci bus. It is also recommended to use the virtio-scsi device instead of virtio-blk as the per-disk memory overhead is smaller.
The SeaBIOS application runs in real mode for compatibility with BIOS interfaces. This limits the amount of memory available. As a consequpci holeence, SeaBIOS is only able to handle a limited number of disks. Currently, the supported number of disks is:

virtio-scsi — 64
virtio-blk — 4
ahci/sata — 24 (4 controllers with all 6 ports connected)
usb-storage — 4

As a workaround for this problem, when attaching a large number of disks to your virtual machine, make sure that your system disk has a small pci slot number, so SeaBIOS sees it first when scanning the pci bus. It is also recommended to use the virtio-scsi device instead of virtio-blk as the per-disk memory overhead is smaller.
Flags needinfo?(kraxel)
Gerd Hoffmann 2015-02-23 14:23:24 UTC Flags needinfo?(kraxel)
Dayle Parker 2015-03-06 03:20:18 UTC Status ON_QA VERIFIED
Dayle Parker 2015-03-06 03:27:07 UTC Comment 14 is private 1 0
Status VERIFIED CLOSED
Resolution --- CURRENTRELEASE
Last Closed 2015-03-05 22:27:07 UTC
John Skeoch 2016-02-01 01:49:42 UTC CC r.landmann
Alasdair Kergon 2019-03-06 01:23:35 UTC Pool ID 220 238

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