On 04/30/2011 11:30 AM, Jussi Hirvi wrote: > I am sure this is really simple. > > I have a setup of 2 disks (sda, sdb) which are outwardly identical, and > are mirrors of each other. Together they form 3 raid1 devices. Both > disks can boot. > > Now sda has bad sectors, and I should replace it. But which one of the > physical disks is sda?? > > The machine boots fine from either one of the disks, (and the booting > disk of course is always called sda). > > In the messages log I see entries like this: > > Apr 29 02:21:07 a134-224 kernel: ata2: SATA link up 3.0 Gbps (SStatus > 123 SControl 300) > > By noticing which SATA link (ata1, ata2) is up and which is down, I can > find out which physical disk is connected to ata1 and which to ata2. > > If both disks are connected, will the hd in ata1 become sda, and the hd > in ata2 become sdb?? > > - Jussi run hdparm -tT /dev/sda and identify sda - it is the one with the blinking LEDs. HTH, Kay