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
2011/4/30 Jussi Hirvi <listmember at greenspot.fi>:> 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??take look at serial number using smartctl http://www.techrepublic.com/blog/opensource/using-smartctl-to-get-smart-status-information-on-your-hard-drives/1389 -- Eero
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?? > > - Jussirun hdparm -tT /dev/sda and identify sda - it is the one with the blinking LEDs. HTH, Kay
> -----Original Message----- > From: centos-bounces at centos.org On Behalf Of Jussi Hirvi > Sent: 30/04/2011 10:31 > To: CentOS mailing list > Subject: [CentOS] Identifying physical disks > > 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?? > > - JussiHow about: ls -l /dev/disk/by-id which on my system gives me: lrwxrwxrwx 1 root root 9 Mar 6 14:34 scsi-SATA_SAMSUNG_HD154UIS1XWJ1BZ900317 -> ../../sdc lrwxrwxrwx 1 root root 9 Mar 6 14:34 scsi-SATA_SAMSUNG_HD154UIS1XWJ1BZ900318 -> ../../sdb lrwxrwxrwx 1 root root 9 Mar 6 14:34 scsi-SATA_SAMSUNG_HD154UIS1XWJ9CZA00454 -> ../../sdd which are my three identical Samsung HD154UI disks. Their serial numbers are the S1XWJ... bits at the end. hth Andy