Hi folks,

I meet a strange problem in 2.6.19 kernel. When I used mdadm(version 2.5.6-9) to create soft raid, for example,
There're two SATA disks, which is recognized by the "/proc/scsi/scsi" as "1:0:0:0" and "2:0:0:0". Use these two disks to create softraid-1:

When the array is created successful, I try to plug out the "/dev/sda" disk. Yes, "mdadm --detail /dev/md0" immediately indicates the array is degraded and remove "/dev/sdb" entry.

It's very interesting here! when I plug back the former "/dev/sdb" to enclosure again, the system recognizes it as "/dev/sdc", however, its scsi ID 2:0:0:0 does not change. Of course the array is still degraded.

In 2.4 kernel, when I repeat the same steps, the re-back "/dev/sdb" is able to recognized as "/dev/sdb" without changing disk name.

How could this happen in 2.6.19 kernel? How could I make the system recognize its old name?

Please give me some hints.

Thanks in advanced.
-Phillip

You don't say on which distro you have this problem, but if device names are given by udev, you can add rules to achieve persistent naming (see here).

Hi uselpa,

Thanks for your help. The underlying operating system is CentOS 4.4.
I'll read the manual and try it later.

Regards,
Phillip