Since the focus of this thread shifted somewhat in the last few messages, I'll try to summarize what has been discussed so far: - There was a number of participants who joined this discussion spontaneously. This suggests that there is considerable interest in networked storage and iSCSI. - It has been motivated why iSCSI makes sense as a storage protocol (compared to ATA over Ethernet and Fibre Channel over Ethernet). - The direct I/O performance results for block transfer sizes below 64 KB are a meaningful benchmark for storage target implementations. - It has been discussed whether an iSCSI target should be implemented in user space or in kernel space. It is clear now that an implementation in the kernel can be made faster than a user space implementation (http://kerneltrap.org/mailarchive/linux-kernel/2008/2/4/714804). Regarding existing implementations, measurements have a.o. shown that SCST is faster than STGT (30% with the following setup: iSCSI via IPoIB and direct I/O block transfers with a size of 512 bytes). - It has been discussed which iSCSI target implementation should be in the mainstream Linux kernel. There is no agreement on this subject yet. The short-term options are as follows: 1) Do not integrate any new iSCSI target implementation in the mainstream Linux kernel. 2) Add one of the existing in-kernel iSCSI target implementations to the kernel, e.g. SCST or PyX/LIO. 3) Create a new in-kernel iSCSI target implementation that combines the advantages of the existing iSCSI kernel target implementations (iETD, STGT, SCST and PyX/LIO). As an iSCSI user, I prefer option (3). The big question is whether the various storage target authors agree with this ? Bart Van Assche. - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
