Re: raid resync speed? - laptop drive-

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]



On 05/21/2010 04:32 PM, Les Mikesell wrote:
> On 5/21/2010 4:19 PM, John R Pierce wrote:
>> Les Mikesell wrote:
>>> But it is just a match for the Seagate drives with the default layout
>>> using one partition that fills the disk.  If I have to skip some amount
>>> at the start of the partition I think that will make the partition size
>>> not match, making it impossible to add as a raid member.
>>>
>>
>> 750GB drives can vary quite a bit in size +/- depending on the exact
>> model.   The required trim is 0-3.5K, and its due to the MBR on the
>> first "track" of the drive before the first/primary partition starts.
>
> The 3.5" Seagates look like:
> Disk /dev/sdc: 750.1 GB, 750156374016 bytes
> 255 heads, 63 sectors/track, 91201 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
>
> Device Boot   Start     End      Blocks   Id  System
> /dev/sdc1     1       91201   732572001   fd  Linux raid autodetect
>
> And the 2.5 WD looks the same to me:
>
> Disk /dev/sdh: 750.1 GB, 750156374016 bytes
> 255 heads, 63 sectors/track, 91201 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
>
> Device Boot  Start         End      Blocks   Id  System
> /dev/sdh1      1       91201   732572001   fd  Linux raid autodetect

You have another way out.  By my calculation, that drive is partitioned
in DOS compatibility mode, which leaves the remainder of the MBR track
unused.  Running fdisk in expert mode ("x" command), you can move the
partition's beginning of data ("b" command) from sector 63 back to
sector 56.  That will give you the needed 4K alignment and a partition
that is no smaller than what it was before.

-- 
Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.

_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos

[Index of Archives]     [CentOS]     [CentOS Announce]     [CentOS Development]     [CentOS ARM Devel]     [CentOS Docs]     [CentOS Virtualization]     [Carrier Grade Linux]     [Linux Media]     [Asterisk]     [DCCP]     [Netdev]     [Xorg]     [Linux USB]
  Powered by Linux