taemun, as I said, it seems the same "problem" happens on filesystems (which are 128Kb by default), where you have a lot of small files.
Maybe if you store dvd images only you don't incur in this wastage of space :) > My problem with the ashift=9 on 4KB sectored drives is that a write of 512B > incurs an enormous hit to latency because the drive is physically reading > 4KB, modifying 512B, and writing 4KB. Which also means that there is the Those 4Kb disk are slow by themselves, I mean, they're good to build "slow" backup systems only, imho. > potential for an error to be made during this operation, silently corrupting > your data. I think that you don't risk corruption, since zfs checksums everything. A zfs filesystem, here on 512b, with solaris nevada version 143 source code and compiled modules mauri...@krumiro:~$ zfs get all iscsi/snv_143 NAME PROPERTY VALUE SOURCE iscsi/snv_143 type filesystem - iscsi/snv_143 creation ven ago 13 10:14 2010 - iscsi/snv_143 used 2,73G - iscsi/snv_143 available 979G - iscsi/snv_143 referenced 2,73G - iscsi/snv_143 compressratio 1.76x - iscsi/snv_143 mounted yes - iscsi/snv_143 quota none default iscsi/snv_143 reservation none default iscsi/snv_143 recordsize 128K default iscsi/snv_143 mountpoint /iscsi/snv_143 default iscsi/snv_143 sharenfs off default iscsi/snv_143 checksum on default iscsi/snv_143 compression on local iscsi/snv_143 atime off local iscsi/snv_143 devices on default iscsi/snv_143 exec on default iscsi/snv_143 setuid on default iscsi/snv_143 readonly off default iscsi/snv_143 zoned off default iscsi/snv_143 snapdir hidden default iscsi/snv_143 aclinherit restricted default iscsi/snv_143 canmount on default iscsi/snv_143 xattr on default iscsi/snv_143 copies 1 default iscsi/snv_143 version 4 - iscsi/snv_143 utf8only off - iscsi/snv_143 normalization none - iscsi/snv_143 casesensitivity sensitive - iscsi/snv_143 vscan off default iscsi/snv_143 nbmand off default iscsi/snv_143 sharesmb off default iscsi/snv_143 refquota none default iscsi/snv_143 refreservation none default iscsi/snv_143 primarycache all default iscsi/snv_143 secondarycache all default iscsi/snv_143 usedbysnapshots 0 - iscsi/snv_143 usedbydataset 2,73G - iscsi/snv_143 usedbychildren 0 - iscsi/snv_143 usedbyrefreservation 0 - iscsi/snv_143 logbias throughput inherited from iscsi/snv_143 dedup off default iscsi/snv_143 mlslabel none default iscsi/snv_143 sync standard default iscsi/snv_143 com.sun:auto-snapshot false inherited from here on 4Kb mauri...@rsync:~$ zfs get all nas/test/snv_143 NAME PROPERTY VALUE SOURCE nas/test/snv_143 type filesystem - nas/test/snv_143 creation lun nov 22 11:12 2010 - nas/test/snv_143 used 3,81G - nas/test/snv_143 available 312G - nas/test/snv_143 referenced 3,81G - nas/test/snv_143 compressratio 1.76x - nas/test/snv_143 mounted yes - nas/test/snv_143 quota none default nas/test/snv_143 reservation none default nas/test/snv_143 recordsize 128K default nas/test/snv_143 mountpoint /nas/test/snv_143 default nas/test/snv_143 sharenfs off default nas/test/snv_143 checksum on default nas/test/snv_143 compression on inherited from nas/test/snv_143 atime on default nas/test/snv_143 devices on default nas/test/snv_143 exec on default nas/test/snv_143 setuid on default nas/test/snv_143 readonly off default nas/test/snv_143 zoned off default nas/test/snv_143 snapdir hidden default nas/test/snv_143 aclinherit restricted default nas/test/snv_143 canmount on default nas/test/snv_143 xattr on default nas/test/snv_143 copies 1 default nas/test/snv_143 version 4 - nas/test/snv_143 utf8only off - nas/test/snv_143 normalization none - nas/test/snv_143 casesensitivity sensitive - nas/test/snv_143 vscan off default nas/test/snv_143 nbmand off default nas/test/snv_143 sharesmb off default nas/test/snv_143 refquota none default nas/test/snv_143 refreservation none default nas/test/snv_143 primarycache all default nas/test/snv_143 secondarycache all default nas/test/snv_143 usedbysnapshots 0 - nas/test/snv_143 usedbydataset 3,81G - nas/test/snv_143 usedbychildren 0 - nas/test/snv_143 usedbyrefreservation 0 - nas/test/snv_143 logbias latency default nas/test/snv_143 dedup off default nas/test/snv_143 mlslabel none default nas/test/snv_143 sync standard default Here, even with a lot better compression we use 3,81Gb instead of 2,73 Best regards. Maurilio. -- __________ | | | |__| Maurilio Longo |_|_|_|____| farmaconsult s.r.l. _______________________________________________ OpenIndiana-discuss mailing list OpenIndiana-discuss@openindiana.org http://openindiana.org/mailman/listinfo/openindiana-discuss