Re[2]: UNEXPECTED SOFTUPDATES INCONSISTENCY
Hello Heinrich, Sunday, February 22, 2004, 5:00:27 PM, you wrote: > Why that? I can imagine that i lose data in case of a power failure, but > why in case of a crash? Well I guess the card COULD still commit the data, however, who knows if it actually does it? > And why is write cache only dangerous with softupdates, as you wrote above? IIRC softupdates relies on the assumption that when the softupdate changes return, they really ARE on the disk. It's the same with most RDBMS: because they go to great lengths to ensure the journal is in an ok state they need to know for sure that the data they wrote to it actually made it to disk. > Since i found no word about disabling write cache in the FreeBSD > handbook or in man tuning(7), i would really like to know, if this is > just a rumour, or where does it come from? I can't say for sure, but I have little confidence in write caching anyhow. It changes semantics the system relies on, for one. Best regards, Gabriel ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re[2]: UNEXPECTED SOFTUPDATES INCONSISTENCY
Hello Heinrich, Sunday, February 22, 2004, 6:49:46 PM, you wrote: > what you write does make sense, although i really can't understand why > this important info is not in the FreeBSD documentation. > I have disabled write cache, but i will keep softupdates disabled as > well for now, and see how the system behaves. I think it was in there. But maybe I'm mixing this with Lehey's excellent but somewhat dated Complete FreeBSD. Anyway, I've been using softupdates since they became avalaible and never had a single problem with them. Can't exactly say the same about ata(4) though but Soren was always very helpful when problems arised. Best regards, Gabriel ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re[2]: UNEXPECTED SOFTUPDATES INCONSISTENCY
Hi Heinrich Rebehn, you wrote. >> Make sure you've disabled write caching on the drive firmware >> itself... HR> Does this also apply for RAID disks (twe)? Also, there is no word about HR> this in man tuning(7). Is this more of a guess or is softupdates HR> definately dangerous with wite cache enabled? I'd say it's the other way round: write cache is dangerous with softupdates. Softupdates itself is certainly better than no softupdates, even if it takes a slight performance drop by disabling write cache. I think you should disable the write cache on the 3ware cache (not sure whether there actually is one, mine don't come with any RAM sockets) anyway as you'll lose all data in there in the event of a crash. Regards, Gabriel ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
