At Mon, 2 Nov 2009 14:47:23 -0800 (PST) CentOS mailing list <centos at centos.org> wrote: > > > > How can I tell wich HDD to swap, when the "cat /proc/mdstat" says one > HDD of the RAID1 array has died? Use '/sbin/mdadm --detail /dev/md<mumble>' and note the drive name (/dev/sd<mumble> for SCSI or SATA, and /dev/hd<mumble> for IDE). Then '/usr/sbin/smartctl -A <drive name from mdadm's listing>' /usr/sbin/smartctl will give you lots of information. Near the beginning is the serial number. You *should* be running smartd and you *should* be enabling all of your disks to be monitored with smartd. > > > > Does the HDD's has some serial numbers, that I can see in "reality", > and I can get that number from e.g.: a commands output? Yes. smartctl will list the disk's info, including serial number. > > > > How could I know wich HDD to swap in e.g.: a RAID1 array? Presumably, you know which disk is connected to which controller port. mdadm will give you the name assigned by the O/S. For IDE this would be /dev/hda -- primary master /dev/hdb -- primary slave /dev/hdc -- secondary master /dev/hdd -- secondary slave for SCSI, the disks get a letter a, b, c, d, etc. on a 'first come first served' basis: disks are scaned in controller order, in id order: controller 0, disk 0, disk 1, disk 2 ... controller 1, disk 0, disk 1 .. ahci SATA treats each SATA port as a separate 'controller', with only one device (0) and the ports are scanned in order. Some SATA controllers can be (are) set up to behave like IDE (PATA) disks, this maps a pair of SATA ports as a master and slave pair of 'IDE' (PATA) disks. This can make things 'interesting'. The Dell PowerEdge 840 is like that. With the SCSI-layer Linux drive, the mapping becomes (when all four are in use): Port 0: (primary master) /dev/sda Port 1: (secondary master) /dev/sdc Port 2: (primary slave) /dev/sdb Port 3: (secondary slave) /dev/sdd Letters are assigned in the order port 0, port 2, port 1, port 3, with unoccupied ports being skipped. > > > > thank you > > > > > > MIME-Version: 1.0 > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > > -- Robert Heller -- 978-544-6933 Deepwoods Software -- Download the Model Railroad System http://www.deepsoft.com/ -- Binaries for Linux and MS-Windows heller at deepsoft.com -- http://www.deepsoft.com/ModelRailroadSystem/