Get partition details in diskperf

In diskperf filter driver how can I get the partition info of all the partitions.

I am using IOCTL_DISK_GET_DRIVE_LAYOUT_EX ioctl to get the partition information.

I am able to get details of partitions from one disk. But if there are more then one disks then how can I gets details of partitions from those disks. I tried but I am getting the return status of 2nd disk as 0x80000010 which means STATUS_DEVICE_OFF_LINE. Can any one explain me how can I solve this problem?

The other disk's partition is primary but does not boot. So may be that is why I am getting the return status as 0x80000010 in windbg at boot time. So how can I get this partition details ones the system has finished loading.

The IOCTL_DISK_GET_PARTITION_INFO_EX control code is supported on basic disks. It is only supported on dynamic disks that are boot or system disks, or have retained entries in the partition table.

http://social.msdn.microsoft.com/Forums/en-US/windowsgeneraldevelopmentissues/thread/35a1d1cc-5948-4554-bbeb-63e014f03328/

http://www.osronline.com/ShowThread.cfm?link=152051