On 03/12/2014 04:23 PM, Dan Mossor issued this missive:
I've been combing the web for a couple days, and most hits I'm finding regarding using a btrfs subvolume as an iSCSI target are posts from the 2009/2010 timeframe stating that that functionality is broken. I'm working on a couple projects here, and one of those involves the research into iSCSI targets and initiators, and the testing thereof. I have an F20 system with a 1.3TB btrfs master subvolume (across three dissimilar devices), and want to create a subvolume within that to serve as an iSCSI target. The traditional methods, specifically those mentioned in the Fedora Wiki and the tgtadm man pages, place the emphasis on using devices (/dev/sdx) or files (dd if=/dev/zero of=/array/target1 bs=1k count=1). I realize that using the file is probably the easiest thing to do in this instance, but that's not the point of my project - I am intentionally trying to designate the btrfs subvolume as the target. The issue I believe that is going to stop me is that tgtadm expects a block device as the target, and btrfs does not provide that. Is there a workaround, other than using a file in the subvolume as the target? Is there work in progress to enable this feature, either in the scsi-target-utils package or within the btrfs framework?
iSCSI stands for "internet SCSI", a way to share raw devices over normal network mechanisms rather than having to have a storage farm (e.g. fiberchannel switches or SAS concentrators and a ton of cables). As far as I know, the functionality you want will never be available. iSCSI is intended to share raw devices, not subdirectories (that's what things like NFS and CIFS are for). By creating a file (on any filesystem) and using that as the iSCSI target, you're using that file as a raw device and the iSCSI consumer can format it to whatever they want (or use the existing filesystem if it knows what it is). ---------------------------------------------------------------------- - Rick Stevens, Systems Engineer, AllDigital ricks@xxxxxxxxxxxxxx - - AIM/Skype: therps2 ICQ: 22643734 Yahoo: origrps2 - - - - Blessed are the peacekeepers...for they shall be shot at - - from both sides. --A.M. Greeley - ---------------------------------------------------------------------- -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
