I have the following setup:
3x4TB RAID-5 (Hardware RAID) (two data disks URE 1 in 10^15)
5x2TB RAID-5 (Hardware RAID) (four data disks URE 1 in 10^15)
= six data disks in total?
These will be encrypted using LUKS and then collected together into a single Volume Group in which I'll create some logical volumes.
So in creating the Volume Group, how will this setup adjust the --physicalextentsize I need to specify (default is 4MiB)? In this case 4MiB might not be a multiple of the stripe-widths of both arrays so will need to change.
Also, when creating an ext4 filesystem that spans over these two arrays, will the stride and stripe-width options still follow these formulae?:
Code:
stride = chunk_size (bytes) / 4096
stripe_width = (number of data disks) * (chunk_size in bytes) / 4096
stripe_width = 6 * (chunk_size in bytes) / 4096
I'm assuming there are six data disks but I'm not sure this is correct since they're of different sizes in different arrays. i.e. four disks are 2TB and two disks are 4TB.
Does anyone know if I've missed something here?
Note: I used
this page to aid me with calculations.
Thanks.