[ale] XFS on Linux - Is it ready for prime time?

[Ed Cashin]

On Thu, Apr 22, 2010 at 9:13 PM, Doug McNash <dmcnash at charter.net> wrote:
>
> So, you think we shouldn't be using Raid5, huh. I asked why Raid5 and they said they wanted the reliability. XFS was chosen because of its reputation for handling large (140M) video files and associated metadata. And yes it is NFS.
>
> The big remaining problem is that periodically the system stalls and may take a few seconds to send back the write acks. At that point the writer assumes the file is not being written and starts tossing data.

You might have to tell the Linux VM subsystem not to leave dirty
pages hanging around too long---there's I/O to do!  Push it to the
backing store!  Free that RAM up for new writes!

http://support.coraid.com/support/linux/EtherDrive-2.6-HOWTO-5.html#ss5.19

Otherwise writes fill up RAM until the system needs some free
pages, then it suddenly stops everything to try to get some by
flushing out dirty data so that pages in the cache are clean.

-- 
  Ed Cashin <ecashin at noserose.net>
  http://noserose.net/e/
  http://www.coraid.com/