Re: mdadm and UUIDs for its component drives

2011-07-03 Thread Luke Kenneth Casson Leighton
On Mon, Jun 27, 2011 at 1:59 PM, Philip Hands p...@hands.com wrote:  ok, i bring in phil now, who i was talking to yesterday about this. what he said was (and i may get this wrong: it only went in partly) - something along the lines of remember to build the drives with individual mdadm

Re: mdadm and UUIDs for its component drives

2011-06-28 Thread Tom H
On Mon, Jun 27, 2011 at 3:19 AM, martin f krafft madd...@debian.org wrote: also sprach Tom H tomh0...@gmail.com [2011.06.27.0851 +0200]: Partitions do not have UUIDs. What you are seeing are the MD UUIDs stored in the superblock of the sda1 device. I called them mdadm UUIDs rather than MD

Re: mdadm and UUIDs for its component drives

2011-06-28 Thread Tom H
On Mon, Jun 27, 2011 at 8:59 AM, Philip Hands p...@hands.com wrote: I must say that I'm a little beffuddled about how you managed to make the system sensitive to which device contains which MD component -- I seem to remember you mentioning that you had devices listed in your mdadm.conf --

Re: mdadm and UUIDs for its component drives

2011-06-27 Thread Tom H
On Mon, Jun 27, 2011 at 12:52 AM, martin f krafft madd...@debian.org wrote: also sprach Tom H tomh0...@gmail.com [2011.06.26.2328 +0200]: mdadm --examine /dev/sda1 returns mdadm UUIDs of the array and the partition. (I've never seen the mdadm UUID of a partition be used for anything. Can an

Re: mdadm and UUIDs for its component drives

2011-06-27 Thread Tom H
On Mon, Jun 27, 2011 at 1:51 AM, Andrew McGlashan andrew.mcglas...@affinityvision.com.au wrote: Tom H wrote: You have / set up as a RAID 1 array md0 with sda1 and sdb1 as its components. No / would be on an internal drive,  right now that is not the concern as it has nothing to do with the

Re: mdadm and UUIDs for its component drives

2011-06-27 Thread martin f krafft
also sprach Tom H tomh0...@gmail.com [2011.06.27.0851 +0200]: Partitions do not have UUIDs. What you are seeing are the MD UUIDs stored in the superblock of the sda1 device. I called them mdadm UUIDs rather than MD UUIDs but they definitely exist, are different from the MD Array UUID, and,

Re: mdadm and UUIDs for its component drives

2011-06-27 Thread Philip Hands
On Sun, 26 Jun 2011 14:42:03 +0100, Luke Kenneth Casson Leighton luke.leigh...@gmail.com wrote: On Sun, Jun 26, 2011 at 2:25 PM, Andrew McGlashan andrew.mcglas...@affinityvision.com.au wrote: I hear what you are saying, but I had a related problem which was similar. well... it's funny,

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Luke Kenneth Casson Leighton
moorning martin: thanks for responding. apologies for not thinking to ask on debian-user earlier, and apologies for the long-winded style: just got ddragged out of bed to go chase a lamb out of the garden that was eating our flowers and vegetables. if i wasn't stumbling about half-asleep or

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Andrew McGlashan
Hi Luke, Luke Kenneth Casson Leighton wrote: the answer is that mdadm tracks down the hardlink and displays, as best i can tell, only that, with no immediately obvious options to get it to display the disk UUIDs. I hear what you are saying, but I had a related problem which was similar.

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Luke Kenneth Casson Leighton
On Sun, Jun 26, 2011 at 2:25 PM, Andrew McGlashan andrew.mcglas...@affinityvision.com.au wrote: I hear what you are saying, but I had a related problem which was similar. well... it's funny, because this is exactly what i need. Anyway the long and short of it is, I can use mdadm without

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread martin f krafft
also sprach Luke Kenneth Casson Leighton luke.leigh...@gmail.com [2011.06.26.1241 +0200]: * is there an option to mdadm to make it display UUIDs instead of or as well as the disk name? mdadm -Es * also, how about making mention of how mdadm works, in the man page somewhere reaaasonably

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Luke Kenneth Casson Leighton
On Sun, Jun 26, 2011 at 2:25 PM, Andrew McGlashan andrew.mcglas...@affinityvision.com.au wrote: Anyway the long and short of it is, I can use mdadm without regard to what devices are found, such as /dev/sda /dev/sdb /dev/sdc and the like as I rely purely on the UUID functionality, which as

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Luke Kenneth Casson Leighton
On Sun, Jun 26, 2011 at 3:11 PM, martin f krafft madd...@debian.org wrote: also sprach Luke Kenneth Casson Leighton luke.leigh...@gmail.com [2011.06.26.1241 +0200]:  * is there an option to mdadm to make it display UUIDs instead of or as well as the disk name? mdadm -Es oo! yaay! there

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Andrew McGlashan
Luke Kenneth Casson Leighton wrote: yes, mdadm names its RAID drives by UUID (as can clearly be seen in /dev/mdadm/mdadm.conf) but does it *also* refer to its *COMPONENT* drives (internally, and non-obviously, and undocumentedly) by UUID and then report to the outside world that it's using

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread martin f krafft
also sprach Luke Kenneth Casson Leighton luke.leigh...@gmail.com [2011.06.26.1634 +0200]: Search manpage for partitions. that's odd. i read around each part (man mdadm^M /partitions^M), paragraph back and forwards: no mention of the UUIDs of drive components of an array was clearly

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread William Hopkins
On 06/27/11 at 01:02am, Andrew McGlashan wrote: Luke Kenneth Casson Leighton wrote: yes, mdadm names its RAID drives by UUID (as can clearly be seen in /dev/mdadm/mdadm.conf) but does it *also* refer to its *COMPONENT* drives (internally, and non-obviously, and undocumentedly) by UUID and

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Luke Kenneth Casson Leighton
On Sun, Jun 26, 2011 at 4:26 PM, martin f krafft madd...@debian.org wrote: also sprach Luke Kenneth Casson Leighton luke.leigh...@gmail.com [2011.06.26.1634 +0200]: Search manpage for partitions.  that's odd.  i read around each part (man mdadm^M /partitions^M),  paragraph back and

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Andrew McGlashan
Hi, Luke Kenneth Casson Leighton wrote: well. that was nice. the scenario you describe is precisely what i sort-of had planned, but didn't have the expertise to do so was going to recommend just two drives and then rsync to the other two. _however_, given that you've solved exactly what is

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Tom H
On Sun, Jun 26, 2011 at 6:41 AM, Luke Kenneth Casson Leighton luke.leigh...@gmail.com wrote: is there an option to mdadm to make it display UUIDs instead of or as well as the disk name? mdadm --examine /dev/sdXY gives you the device and the array UUIDs. mdadm --examine --scan gives you the

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Tom H
On Sun, Jun 26, 2011 at 9:55 AM, Luke Kenneth Casson Leighton luke.leigh...@gmail.com wrote: On Sun, Jun 26, 2011 at 2:25 PM, Andrew McGlashan andrew.mcglas...@affinityvision.com.au wrote: Anyway the long and short of it is, I can use mdadm without regard to what devices are found, such

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Tom H
On Sun, Jun 26, 2011 at 11:29 AM, William Hopkins we.hopk...@gmail.com wrote: It seems to me that you'd be well served by simply using the UUID (by-uuid, not by-id) in all things, including mounting and managing. Then you would never need to figure out which disk sda was, you could just

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread martin f krafft
also sprach Tom H tomh0...@gmail.com [2011.06.26.2328 +0200]: mdadm --examine /dev/sda1 returns mdadm UUIDs of the array and the partition. (I've never seen the mdadm UUID of a partition be used for anything. Can an array be assembled by referring to an mdadm UUID of a partition to add a

Re: mdadm and UUIDs for its component drives

2011-06-26 Thread Andrew McGlashan
Tom H wrote: You have / set up as a RAID 1 array md0 with sda1 and sdb1 as its components. No / would be on an internal drive, right now that is not the concern as it has nothing to do with the external drive array(s) in question for this issue. -- Kind Regards AndrewM -- To