Anand Avati a écrit : > >> Let's continue with this scenario: what would happen if one of the clients >> changed hello.c again, and the failed server came up again after some >> extended repair period? >> >> What exactly would be the criteria for file resync? (Imagine one of the >> copies got corrupted during fsck, while still carrying identical metadata >> information) > > a server which had 'gone down' is not put in operation until it > undergoes an FSCK. the one with the latest mtime is the 'freshest' > copy. > > > avati > Let's take the same configuration (we assume that self heal translator is on) with this scenario : Client1 is writing a huge file on the afr volume (like 200Mb file size) Let's say that during this writing (that will take some time), Server 2 goes down, and then comes back a little after but *before* the wrting is completed. As you said, Server2 will not be "up" until a successful fsck is performed. As I understood it, fsck could be performed only if no clients access the afr volume in some ways. So then, what would happen if Client2 is a service that continuously write something on the afr volume ? (like database insertions, or mail generation, or simply a real-time log of something..) Will Server2 never come up ? Here is another scenario : Client1 and Client2 are accessing the AFR for different manners. (for instance, one is a mail service that writes everything that come through and the other is a database) Is there anything like a load-balancing process or are both clients writes on server1 which instantly replicates ? What happen if the link between the 2 servers is severed ? Let's say that Client1 can still access the volume through Server1, Client2 only through Server2, AND Server1 can't comunicate with Server2 (what a worse-case-scenario !) And last but not least : let's now say that Client1 and Client2 run the same service (= access the same data). What would happen ? (Isn't that what you've called "split brain" ?) I have another scenario, but I think it's enough for now, don't you ? So Sorry, Enkahel Sebastien LELIEVRE slelievre@xxxxxxxxxxxxxxxx Services to ISP TBS-internet http://www.TBS-internet.com/
