[CentOS] raid resync speed? - laptop drive-

[Les Mikesell]

On 5/24/2010 6:56 AM, Robert Nichols wrote:
>
>>
>> The trayless internal hotswap enclosures claim to be good for 10,000+ insertions
>> and I'm using larger ones for the desktop drives I had been using without any
>> problems.   I have seen some postings to the effect that I need a newer kernel
>> to recognize the 4k sectors besides doing the partition alignment.  Maybe I can
>> boot the RHEL 6 beta or a fedora iso and see if they are faster.
>
> Sounds good, unless that 10,000 insertion spec is predicated on spreading
> the usage among 200 drives such that no individual drives has more than
> 50 insertions.  ;-(
>
> BTW, I got carried away typing zeros in that spec. for the eSATA connector.
> The right number is 5,000 insertions, not 50,000.
>
> If you want a good write-up on what the kernel developers have to contend
> with to handle these 4KiB sector sizes, see
>     https://ata.wiki.kernel.org/index.php/ATA_4_KiB_sector_issues
>
> For those with a strong stomach for such things, a nice historical
> perspective on the horrors of ever-increasing drive sizes can be found
> at http://www.win.tue.nl/~aeb/linux/Large-Disk.html .  Just be sure to
> keep the 2004 date in mind when it mentions "recent kernels."

I booted a RHEL6 beta DVD in rescue mode, but it wasn't any better. 
That version of fdisk does show:
Logical/Physical Sector size    512 bytes
though, so it's probably hopeless.   Oddly, that version of fdisk 
wouldn't let me move the beginning back below 63 either - but I did that 
with the 5.x fdisk.

-- 
   Les Mikesell
     lesmikesell at gmail.com