High availability email server...

[Tom Samplonius]

Pascal Gienger wrote:
> David Korpiewski <davidk at cs.umass.edu> wrote:
>
>> I spent about 6 months fighting with Apple XSAN and Apple OSX mail to 
>> try
>> to create a redundant cyrus mail cluster.  First of all, don't try 
>> it, it
>> is a waste of time.  Apple states that mail on an XSAN is not supported.
>> The reason is that it simply won't run.   The Xsan can't handle the 
>> large
>> amount of small files and will do things like disconnect or corrupting
>> the file system.
>
> STOP!
> The capability to handle small files efficiently is related to the 
> filesystem carrying the files and NOT to the physical and logical 
> storage media (block device) under it.
  Apple is the one confusing people.  "XSan" is the name of the Apple 
cluster file system.  So you configure a couple of hosts on your SAN, 
with a shared volume, and then run XSan.  XSan is more similar to Linux 
GFS (Global File System).

  So I believe the original poster is right:  XSan is crap for lots of 
small files.  That is not surprising.  It is really hard to come up with 
a shared file system that does suck.  The nodes have to lock for 
meta-data updates.  So shared file systems can be pretty slow too.

Tom