Hello Wee, Thursday, April 26, 2007, 4:21:00 PM, you wrote:
WYT> On 4/26/07, cedric briner <[EMAIL PROTECTED]> wrote: >> okay let'say that it is not. :) >> Imagine that I setup a box: >> - with Solaris >> - with many HDs (directly attached). >> - use ZFS as the FS >> - export the Data with NFS >> - on an UPS. >> >> Then after reading the : >> http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide#ZFS_and_Complex_Storage_Considerations >> I wonder if there is a way to tell the OS to ignore the fsync flush >> commands since they are likely to survive a power outage. WYT> Cedric, WYT> You do not want to ignore syncs from ZFS if your harddisk is directly WYT> attached to the server. As the document mentioned, that is really for WYT> Complex Storage with NVRAM where flush is not necessary. What?? Setting zil_disable=1 has nothing to do with NVRAM in storage arrays. It disables ZIL in ZFS wich means that if application calls fsync() or opens a file with O_DSYNC, etc. then ZFS won't honor it (return immediatelly without commiting to stable storage). Once txg group closes data will be written to disks and SCSI write cache flush commands will be send. Setting zil_disable to 1 is not that bad actually, and if someone doesn't care to lose some last N seconds of data in case of server crash (however zfs itself will be consistent) it can actually speed up nfs operations a lot. btw: people accustomed to Linux in a way have always zil_disable set to 1... :) -- Best regards, Robert mailto:[EMAIL PROTECTED] http://milek.blogspot.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
