Re: mdadm: /dev/md0 has been started with 1 drive (out of 2).

[Adam Goryachev <mailinglists@websitemanagers.com.au>]

On 05/11/13 22:32, Ivan Lezhnjov IV wrote:
> I checked out mdadm man page, read some pages on the web, and well, what bitmap chunk size should I go for considering these are WD Elements 2TB drives (what kind of technical information about these drives are relevant when considering a bitmap chunk size?)
> 

Other users might have a better suggestion, but I usually just use the
default.

The only time this will matter is if performance is really important to
you, then you can force a larger bitmap chunk size which will result in
more data being copied during a resync, but less bitmap updates,
therefore possibly better performance.

I mainly use it where I can't afford the 30 hours of resync time.

Regards,
Adam

> Ivan
> 
> On Nov 5, 2013, at 12:04 PM, Adam Goryachev <mailinglists@websitemanagers.com.au> wrote:
> 
>> Personally, I would also do:
>> mdadm --grow /dev/md0 --bitmap=internal
>> This means next time you have a similar issue, when you add the older
>> drive, it will only sync the small parts of the drive that are out of
>> date, instead of the entire drive.


-- 
Adam Goryachev
Website Managers
www.websitemanagers.com.au