Robert Milkowski writes: > 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. >
...set zil_disable...speed up nfs...at the expense of a risk of corruption of the NFS client's view. We must never forget this. zil_disable is really not an option IMO. -r > > -- > 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 _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
