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so there are numerous sites taking about using vdevs made from disk partitions like this in order to reorder vdevs of different sizes. however, i have the following physical disks:

Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

if i wanted to consolidate the two 1TB disks and move zfs vdevs onto the 2TB disk, the two recommended methods are:

  • partition the 2TB drive into 2 1TB partitions
  • format the 2TB and create two files

my question isn't so much which is better (although that would be an interesting discussion), but more the sizing of it all: given that my 2TB drive has 2000398934016 bytes, half of it (ie 1TB) is 1000199467008 bytes. the issue is that my 1TB physical drives report as being 1000204886016 bytes - which is MORE than half of the 2TB drive (it's more obvious with the cylinder counts).

wouldn't zfs have issues with a replace given that the vdev sizes would be different?

share|improve this question
    
Are you asking how to consolidate 2 physical vdevs inside a larger pool into 1 physical vdev within that larger pool, or are you asking how to consolidate a zpool made up of just these 2 x 1 TB vdevs into a zpool made up of one 1 x 2 TB vdev? They're very different answers. – Nex7 Jul 24 '13 at 17:42

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