On Tue, 11 Oct 2005 21:55:30 +1000 "Rod.. Whitworth" <[EMAIL PROTECTED]> wrote:
> RAID 1 (or any RAID really) is NOT a backup. It is a high availability > system. > High availability does NOT mean never unavailable. Hello again Rod, I've been looking at ways to make a redundant and load balanced SAN. As you put it, it's not high reliability, once you get a problem with RAID, or the box that it's attached to, you can consider the data 'unknown'. The best solution that I have seen is, although a bit of overkill, AFS (Andrew File System). It's kerberos based authentication on a token basis. Although I have not implemented it I see that it falls short because the tokens (if used) expire after 10 hours, which might require a cron job (if that fails does hell break loose?). Because it is limited to a single read/write node per volume, I see that a volume would be required for every directory that might take more than a few minutes to replicate to the read only nodes to avoid hammering the read/write node. All the other network distributed file systems seem under developed or unstable. FWIW there is something called DRBD which is considered the closest thing to RAID-0 over a network, it can fail sometimes with flaky results in testing. I have found it to be troublesom when problems occur during sync. Do you or anyone else know of anything that works better? -- Regards, Ed http://www.usenix.org.uk
