[CentOS] raid resync speed? - laptop drive-

Sat May 22 21:34:49 UTC 2010
Les Mikesell <lesmikesell at gmail.com>

Robert Nichols wrote:
> On 05/22/2010 11:29 AM, Les Mikesell wrote:
>> Robert Nichols wrote:
>>> On 05/21/2010 07:39 PM, Robert Nichols wrote:
>>>> 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.
>>> Right idea, not the right procedure.  You'll need to turn off DOS
>>> compatibility mode, then create the partition, and then go into
>>> expert mode and move the beginning of data from sector 1 to sector
>>> 56.
>>>
>> It ended up like this, but still sync'ing at about 4M/sec instead of 40.
>>
>>
>> Expert command (m for help): p
>>
>> Disk /dev/sdh: 255 heads, 63 sectors, 91201 cylinders
>>
>> Nr AF  Hd Sec  Cyl  Hd Sec  Cyl     Start      Size ID
>>    1 00   0   2    0 254  63   64         56 1465144009 fd
> 
> Is that one of those WD drives that falsely reports its physical sector
> size as 512 bytes?  I don't know if the kernel can always do the right
> thing when that happens, but all the reports I've seen say that getting
> the start of the partition aligned properly is sufficient.
> 
> What does "hdparm -I /dev/sdh | grep 'Sector size'" show?

It doesn't mention sector size.  All of the size related options seem to match 
the Seagate desktop drive.

-- 
   Les Mikesell
    lesmikesell at gmail.com