Re: [OpenAFS] Read-only replication
Am Donnerstag 17 Juni 2010, 01:06:34 schrieb Jaap Winius: > This subject is confusing to me, because I've learned that once a > client has encountered a read-write mount point, it becomes biased > towards accessing only read-write replicas beyond it, ignoring any and > all perfectly usable read-only volumes that may be available. Not quite. See http://docs.openafs.org/AdminGuide/ch05s07.html#HDRWQ209 HTH... Dirk signature.asc Description: This is a digitally signed message part.
Re: [ SPAM? ] [OpenAFS] Read-only replication
Quoting Lars Schimmer : Simple - Load Balancing. Imagine a cell at three countries hold together by small ISDN lines - a RO copy local to each faculty and the have fast access. Yes, but "In an organization where it is only necessary for an administrator to either give users read-write access to volumes, or no access at all," what good is that? As far as I can tell, in your scenario the clients at the two remote sites would have a bias towards reading the (for them) remote read-write replicas and thus ignore any local read-only copies. Of course, you could also try to explain to those users that they should use one path to read stuff (because it's faster) and another to write or add new files, but I doubt that would go down very well with them. Cheers, Jaap PS -- I just thought of one reason why replicas would help, even in my hypothetical "read-write or nothing" organization above: if one extra server has read-only copies of everything, the volumes can be backed up any any time without bothering anybody. ___ OpenAFS-info mailing list OpenAFS-info@openafs.org https://lists.openafs.org/mailman/listinfo/openafs-info
Re: [ SPAM? ] [OpenAFS] Read-only replication
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Jaap Winius wrote: > Hi folks, > > Here's a hypothetical question regarding the replication of AFS volumes: > > In an organization where it is only necessary for an administrator to > either give users read-write access to volumes, or no access at all, > what would be the advantage of creating any read-only replicas, beyond > those for the standard volumes at the root of the AFS namespace? > > This subject is confusing to me, because I've learned that once a client > has encountered a read-write mount point, it becomes biased towards > accessing only read-write replicas beyond it, ignoring any and all > perfectly usable read-only volumes that may be available. > > Of course, read-only replicas with hourly releases can be used as a > safety net, allowing data to be more quickly recovered in the event of a > failure, but if that's viewed as an unnecessary measure, then what other > reasons reasons might there be for replicating any volumes? Simple - Load Balancing. Imagine a cell at three countries hold together by small ISDN lines - a RO copy local to each faculty and the have fast access. > Thanks, > > Jaap MfG, Lars Schimmer - -- - - TU Graz, Institut für ComputerGraphik & WissensVisualisierung Tel: +43 316 873-5405 E-Mail: l.schim...@cgv.tugraz.at Fax: +43 316 873-5402 PGP-Key-ID: 0x4A9B1723 -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkwZ1cAACgkQmWhuE0qbFyPG8wCfRSYpuQUi72fsWlAD2QcrPvuh rN8AnRVy3I81Zf2AZHs84QoKnZ2vFYX0 =IffC -END PGP SIGNATURE- ___ OpenAFS-info mailing list OpenAFS-info@openafs.org https://lists.openafs.org/mailman/listinfo/openafs-info
[OpenAFS] Read-only replication
Hi folks, Here's a hypothetical question regarding the replication of AFS volumes: In an organization where it is only necessary for an administrator to either give users read-write access to volumes, or no access at all, what would be the advantage of creating any read-only replicas, beyond those for the standard volumes at the root of the AFS namespace? This subject is confusing to me, because I've learned that once a client has encountered a read-write mount point, it becomes biased towards accessing only read-write replicas beyond it, ignoring any and all perfectly usable read-only volumes that may be available. Of course, read-only replicas with hourly releases can be used as a safety net, allowing data to be more quickly recovered in the event of a failure, but if that's viewed as an unnecessary measure, then what other reasons reasons might there be for replicating any volumes? Thanks, Jaap ___ OpenAFS-info mailing list OpenAFS-info@openafs.org https://lists.openafs.org/mailman/listinfo/openafs-info
