[linux-lvm] lvm and md

[Luca Berra]

Peter Yao wrote:
>> why would you need to hide the hardware details from md ?
> 
> I am using some hot-plugging disks and their device number may change 
> after reboot. For example, if i build md with /dev/sda and /dev/sdb, 
> after reboot md may cannot start because the two disks' device name 
> change to /dev/sdc and /dev/sdd. If i build md on top of lvm this 
> problem is avoided. Can you give me some advice for this issue?

it depends on what you use to start your md devices, using raidstart 
with an /etc/raidtab file shows this behaviour, using auto-detect does 
not but is only available at boot. best thing would be to use mdadm 
instead of raidstart

http://www.cse.unsw.edu.au/~neilb/source/mdadm

with this you can define your raid arrays based on UUID instead.

to create mdadm conf file use:

echo "DEVICE partitions" >> /etc/mdadm.conf
mdadm -E -s |grep ARRAY >>  /etc/mdadm.conf

-- 
Luca Berra -- bluca at comedia.it
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