I strongly considered this option at one time with a shared DAS/RAID between my primary and secondary ZSS. I never ended up doing this because of concerns. Out of curiosity, with shared storage over SCSI/SAN, do you have any thoughts on how to overcome the following issues? 1 - Data fencing (using SAN switches+integrated software, or STONITH devices, or something)?? 2 - Clean up a broken FileStorage? To what degree can this be successfully automated without manual intervention of a sysadmin? 3 - Deal with accidental damage to the storage done by the primary node, perhaps due to asynchronous writes to the file? It really seems like replication is really a less brittle option (though how much less brittle, I'm not sure). Though not committed at this point, for a big project I am working on, I am strongly considering use of DirectoryStorage and its snapshot capabilities for low-tech replication (via find+cpio+nfs) to try and minimize issues I might face similar to #2 and #3 if I had chosen FileStorage. Sean -----Original Message----- From: Bill Anderson [mailto:bill@libc.org] Sent: Wednesday, September 11, 2002 3:20 PM To: Paul Winkler Cc: zope@zope.org Subject: Re: [Zope] Zope Myths? On Wed, 2002-09-11 at 09:54, Paul Winkler wrote:
On Wed, Sep 11, 2002 at 03:01:14PM +0100, Paul Browning wrote:
What have we understated/exaggerated/misunderstood?
AFAIK, ZEO still does not allow you to distribute your ZODB. There is still a single, central ZEO server with a single ZODB.
Actually, using shared storage, such as one may have on a SAN, or using a shared SCSI bus (I *strongly* recommend the FC-SAN route over the shared SCSI ;), and a fail over server setup, you can indeed provide fail-over ZODB services. Yes, I know fibre channel SANs are beyond the means of most on the list, but it is certainly possible. In fact, I know of a way to provide multi-site fail over using ZODB and SAN technology on Linux. In fact, if one had one of the IBM zSeries boxes ... mmm toys .... I've yet to try it out (looking for a new job takes too much time in this market), but I believe one could use this method and provide multiple read-only ZEO servers for the same DB. -- Bill Anderson Linux in Boise Club http://www.libc.org Amateurs built the Ark, professionals built the Titanic. Amateurs build Linux, professionals build Windows(tm). _______________________________________________ Zope maillist - Zope@zope.org http://lists.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope-dev )