[CentOS] ext4, 4k sector alignment

Mon Jul 25 21:05:48 UTC 2011
Brian Mathis <brian.mathis+centos at betteradmin.com>

> On 7/25/2011 1:42 PM, Brian Mathis wrote:
>>
>> I've wondered many times, though haven't tried it, if the issues with
>> hard links and backuppc could be solved by using a container file with
>> a loopback mount, and then that file could be moved around as needed
>> without running into hard-link issues.
>>
>> In this case, you could format the external drive in the optimal mode
>> for 4k sectors, then create a container file and mount it using
>> loopback.  Then add the loopback device to the mdraid and have it
>> sync.
>
> It doesn't really help with the problem as it stands, which is that the
> target disk (a swappable sata, not really external) has no extra space
> that would permit shifting the alignment.  It might work to shrink the
> existing size, then partition the new drives with the right offset, but
> I may just start from scratch and keep the old drives around in case I
> need the old history.
>
> --
>   Les Mikesell
>    lesmikesell at gmail.com


I thought this was a 3-disk RAID1?  Can't you repartition the hotswap
disk and still have the data on the other 2?  Why would you need to
shrink the existing partition?  Just blow it away and resync the data
once you rebuild the disk.


-☙ Brian Mathis ❧-