[CentOS] Centos/Linux Disk Caching, might be OT in some ways

Les Mikesell lesmikesell at gmail.com
Thu Jan 28 16:18:11 UTC 2010


On 1/28/2010 8:48 AM, Ross Walker wrote:
>
>>> Sorry to be the bearer of bad news, but on top of LVM on CentOS/RHEL
>>> the best assurance your going to get is fsync(), meaning the data is
>>> out of the kernel, but probably still on disk write cache. Make sure
>>> you have a good UPS setup, so the disks can flush after main power
>>> loss.
>>
>> Or turn off write caching...
>
> Have you tried doing any kind of write with write caching turned off?
> It is so horribly slow to make it almost useless.
>
> If you need to turn write-caching off then I would start looking at
> SSD drives with capacitor based caches.
>

I wonder if the generally-horrible handling that linux has always done 
for fsync() is the real reason Oracle spun off their own distro?  Do 
they get it better?

-- 
   Les Mikesell
    lesmikesell at gmail.com


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