Re: Disable read/write caching to disk?

On May 26, 2005, at 9:52 PM, Scott Long wrote:

> Chad Leigh -- Shire.Net LLC wrote:
>
>
>> On May 26, 2005, at 8:49 PM, Eric Anderson wrote:
>>
>>>
>>> So it sounds dangerous, but not disastrous..  Sounds like soft-  
>>> updates would help this alot, so I'll turn them back on for this   
>>> filesystem (I typically do use it).
>>>
>>> At a minimum, it would be awesome to even have a way to do one  
>>> host  rw and several doing ro.  Think of the case of a web server  
>>> farm,  where it's nearly all reads.
>>>
>>> Thanks for the details and information!
>>>
>> use NFS or something. Not ideal but it allows you to have lots of   
>> clients using the same space without the disasters.
>> Chad
>>
>
> NFS and Coda/AFS require that you have an intelligent node, i.e. a
> computer, in front of each disk.  The whole idea of a Fibre Channel
> or iSCSI SAN is that you have a network of disks connected to a  
> network
> of computers, all able to communicate with each other and not have to
> be fronted by a computer.  This is quite important for high- 
> availability
> storage networks that want the reliability and scalability of not  
> having
> a single computer be the choke point or single-point-of-failure for a
> particular set of data.  Granted it's still somewhat of a niche,  
> but as
> persistent storage and data mining become more part of the mainstream,
> it'll start becoming very important.  Right now FreeBSD simply  
> isn't an
> option, while Solaris, NT, and Linux are.

And OpenVMS :-)

Agreed, but as you say, FreeBSD is not there yet, and since the OP is  
on FreeBSD, and wants to have multiple computers attached, NFS would  
be one way of making that happen.  And if you leave the other  
computers attached by the FC but not mounted, if on goes down, you  
can replace it with another, and switch your nfs server over.  Not as  
ideal but doable on FreeBSD.

Best
Chad