Thanks Nico!

Anyone else want to comment?  I'd like to hear people's opinions about such
issues.  When one is not 100% involved in such efforts, it helps to have input
from people who are or have dealt with similar issues.

On a related note, this is probably the last disk array I want to put together
myself. I discovered to my exasperation that I needed enterprise class drives
because of the TLER effect.  The next disk array I buy will be a ready-made
appliance.


On 11/14/2012 08:58 PM, Nico Kadel-Garcia wrote:
> On Wed, Nov 14, 2012 at 12:37 PM, Stephen John Smoogen <[log in to unmask]> wrote:
>> On 14 November 2012 10:20, Ken Teh <[log in to unmask]> wrote:
>>> The common thread is I/O to a MegaRAID raid5 device.  Which is cause for
>>> concern since the primary function of both machines where I've encountered
>>> this problem is file-serving.
>>>
>>> Perhaps I am just unlucky and have 2 bad MegaRAID cards in a row.  I'm
>>> trying
>>> to understand this better, figure out if I am doing something wrong.
>>
>> Well there are a couple of issues this could be:
>>
>> 1) You are asking more than the MegaRaid is meant to do... it may be
>> running out of cache, or other resources.
>
> My experience with MegaRAID has been *horrible*. Poor driver
> compatibility, awkward and destructive firmware, and deceitful
> specifications only start the list of horrible failures. Their best
> technological use is as doorstops.
>
>> 2) The megaraid is still rebuilding its array beneath and you are
>> hitting a locking problem because it hasn't finished what it needs to
>> do before you ask it to do something else (really sort of #1).
>>
>> Most of the time you will need to install the proprietary Megaraid
>> tools to see what is going on under the disks to find out.
>
> See above: good luck getting those tools working!
>
> Every hour you spend waiting on those things to come to their senses,
> or trying to debug them, is an hour wasted on problems that may not
> ever be solved by your efforts. I encourage you to replace them with a
> better quality manufacturer: Adaptec makes very solid, not too
> expensive controllers, and Rocketport remains the cream of the crop.
>