I'm trying to disable write-caching for devices exported via iSCSI by tgtd 0.9.5. According to http://lists.wpkg.org/pipermail/stgt/2008-June/001699.html I should be able to do this with tgtadm -L iscsi -m logicalunit -o update -t $TID -l $LUN \ -P mode_page=8:0:18:0x10:0:0xff:0xff:0:0:0xff:0xff:0xff:0xff:0x80:0x14:0:0:0:0:0:0 (Both of the patches listed seem already to be in the newly released tgtd 0.9.5.) However, despite having run this for the LUN concerned before logging in to it with an initiator, I'm still getting uncached writes (far too fast for the underlying disk) when I do an O_SYNC/O_DIRECT write to the /dev/sdX on a remote machine. O_DIRECT/O_SYNC writes to the local block device run at the expected speed, of course. My sequence of commands to export looks like tgtadm -L iscsi -m target -o new -t $TID -T $TARGET tgtadm -L iscsi -m logicalunit -o new -t $TID -l 1 -b $DEVICE tgtadm -L iscsi -m logicalunit -o update -t $TID -l 1 -P mode_page=8:0:18:0x10:0:0xff:0xff:0:0:0xff:0xff:0xff:0xff:0x80:0x14:0:0:0:0:0:0 tgtadm -L iscsi -m account -o bind -t $TID -u $USER tgtadm -L iscsi -m target -o bind -t $TID -I ALL and everything is apparently working fine apart from the unwanted write caching. I'm testing using tgtd 0.9.5 with the kernel target driver from stock linux 2.6.28.2 (amd64). My initiator is also linux: iscsi_tcp from 2.6.28.2. Any suggestions as to what I'm doing wrong would be greatly appreciated. Best wishes, Chris. -- To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
