Core-iSCSI

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{{Infobox software | name = Core-iSCSI | logo = [[Image:Corp_Logo.png|180px|Logo]] | screenshot = iSCSI Initiator | caption = | collapsible = | author = {{Nicholas Bellinger}} | developer = {{RTS legal}} | released = {{RTS releases|Core-iSCSI|initial_date}} | discontinued = | latest release version = {{RTS releases|Core-iSCSI|release_ver}} | latest release date = {{RTS releases|Core-iSCSI|release_date}} | latest preview version = {{RTS releases|Core-iSCSI|preview_ver}} | latest preview date = {{RTS releases|Core-iSCSI|preview_date}} | status = {{RTS releases|Core-iSCSI|status}} | frequently updated = | programming language = C | operating system = Linux | platform = | size = | language = | genre = iSCSI Initiator | license = Proprietary commercial software | website = {{RTS website}} }} '''Core-iSCSI''' is a high-performance iSCSI Initator<ref>{{cite web| url=http://groups.google.com/group/Core-iSCSI/browse_frm/thread/20f458bde0883e61/#| title=Core-iSCSI v1.6.2.9 Released| author=Nicholas Bellinger| work=Core-iSCSI mailing list| date=2006-07-04}}</ref> by {{RTS full}}. Core-iSCSI has a number of features that significantly improves the performance over [[Open-iSCSI]]. == Performance == {{Review | date=2010-11-05}} Unfortunately, many Linux SAN installations are lacking performance, even with high-end arrays, because the default Linux initiator [[Open-iSCSI]] is lacking a number of features that are essential to achieve optimal throughput and IOPS. These features include, most notably, a lock-less multithreaded architecture and iSCSI [[Multiple Connections per Session|MC/S]]. {{RTS full}} has developed Core-iSCSI, a high-performanc iSCSI Initiator that alleviates the shortcomings of the standard Linux Initiator [[Open-iSCSI]] (see e.g., the [[Kernel-based Virtual Machine#Benchmarking|KVM]] results). In addition, {{RTS short}} has put together a number of performance patches for the Linux kernel. For instance, one patchset that was developed together with Intel Labs and IBM significantly reduced lock-contention in the Linux storage subsystem, which reduced CPU utilization by up to 20% and can increase IOPS by up to 50%.<ref>{{cite web| |title=Quick merge window note..| url=http://marc.info/?l=linux-kernel&m=129445043102014&w=2| author=Linus Torvalds| work=Linux-kernel mailing list| date=2011-01-07}}</ref> {{RTS short}} provides these patches along with Core-iSCSI to optimize its SAN installations end-to-end. == {{anchor|building_and_installing}}Building and installing == * Compile Core-iSCSI * Install it: <pre> KERNEL_DIR=/usr/src/linux && make install </pre> * Compile Core-iSCSI-Tools * Install them: <pre> make install </pre> * Core-iSCSI is then loadable via <code>iscsi_initiator_mod.ko</code>, and the core tools rely on: <code>/etc/sysconfig/initiator</code>: <pre> CHANNEL="0 2 eth0 192.168.55.6 3260 0" </pre> and <code>/etc/sysconfig/iscsi_device_maps</code>: <pre> DEVICE="0 0 1 diska" </pre> == Interoperability == The following third-party iSCSI target implementations have been validated, have pending TODO items, or are completely untested against Core-iSCSI. We'd be glad to hear feedback on your experiences with all Linux/iSCSI implementations! Note that this list relates to interoperability with Core-iSCSI, but feedback for [[Open-iSCSI]] is also encouraged. === Optional RFC-3720 Features === * [[Multiple Connections per Session]] (MC/S): Tested: OK === Transports === * [http://en.wikipedia.org/wiki/Transmission_Control_Protocol TCP] Tested: OK * [http://en.wikipedia.org/wiki/SCTP SCTP] Tested: OK === [[iSNS]] === * Microsoft Client Tested: OK * PyX/[http://www.sbei.com SBEi] Client Tested: OK === iSCSI Targets === * [[Core-iSCSI/Cisco MDS 9216i|Cisco MDS 9216i]]: Tested : OK * Adaptec/SNAP: Untested (SHOULD WORK) | ([[Multiple Connections per Session|MC/S]]) * Eurologic: Tested : OK * Falconstor: Tested : PENDING (problems with I/O) * IET: Tested : OK * [[Core-iSCSI/Infortrend|Infortrend]]: Tested : FAILED * LeftHand: Tested : OK * Netapp: Tested : OK * Promise: Tested : OK * PyX/[http://www.sbei.com SBEi]: Tested : OK | ([[Multiple Connections per Session|MC/S]]) ** [[Multiple Connections per Session|MC/S]] : STABLE *** Login of connections on the fly *** Logout of connections on the fly *** Logout of connection on the fly by sending logout request on different connection ** iSNS Client : STABLE *** Servers **** Microsoft iSNS Server : STABLE **** SBEi iSNS Server : STABLE *** Registration: /sbin/isns_register *** Deregistration: /sbin/isns_deregister *** Status: /sbin/isns_is_node_registered *** Network Portals: /sbin/isns_network_portals *** iSCSI Index: /sbin/isns_iscsi_index * Sanrad: Tested : OK | [[MC/S]] ** [[Multiple Connections per Session|MC/S]] : STABLE ** [[Multiple Connections per Session|MC/S]] on a V-Switch 3000 running 3.1.14 (?) software appears to work for only one of multiple advertised targets. All others fail to add the secondary connection. ** Interrupting the original connection did not appear to fail-over to the added connection. ** Interrupting the added connection instead has not yet been tested. ** Attempting to get non-production V-Switch 3000 to help core-iSCSI determine whether initiator or target is at fault. [NO UPDATE] ** Sanrad V-Switch 3000 [[ERL=2]] supported with PyX/SBEi iSCSI Initiator (11/2006) * Stringbean: Untested (should work) * UNH: Tested : OK * Wasabi: Tested : OK == [[Diskless boot]] == === Overview === The logic required to run Linux iSCSI for your root device and be able to shutdown and reboot cleanly ("[[diskless boot]]") involves the following: # Core-iSCSI kernel threads that are providing iSCSI services SHOULD NOT be shutdown. Note that ''killall5'' leaves kernel threads alone, but may cause problems with user-level iscsi daemons. # Considerations for session reinstatement during shutdown while iSCSI LUNs (not limited to the root device) are being unmounted. # Miscellanous failures during shutdown caused by <code>nopin_response_timeout</code>, <code>datain_timeout</code>, <code>cmdsn_timeout</code>, transport layer resets, and communication path PHY loss. Most of this logic is distribution agnostic, but sometimes shutdown scripts do the 'network backed root device' (think nfsroot shutdown) that is required to make iSCSI initiators perform diskless shutdown properly. == {{anchor|DVT}} Domain Validation Tool == === Overview === The Core-iSCSI Domain Validation Tool (DVT) is primarly targeted to iSCSI vendors and developers for testing data IO using a CLI program accepting a block device as an argument. The DVT executes a pre-determined number of loop iterations, each time negotiating a different set of RFC-3720 parameter keys until the configuration space has been exhausted. DVT will perform iSCSI Login, a script defined test operation, and Logout on a defined network portal. The sequence of steps is determined by which keys are enabled for testing, type, minimum and maximum settings as defined by RFC-3720. {{anchor|SDV}}SCSI domain validation is goverened by a [http://www.t10.org/drafts.htm T10 Working Draft]: * '''SCSI Domain Validation''' ('''SDV'''): SDV is an NCITS Technical Report describing testing techniques to validate the communication capability of the SCSI physical layer. Status: Released. 11/6/2001 === Download === * DVT sources and binaries: [http://www.linux-iscsi.org/builds/core-iscsi-dv/core-iscsi-dv-v1.0.tar.bz2 <code>core-iscsi-dv-v1.0.tar.bz2</code>] (requires [[#Core-iSCSI Tools|Core-iSCSI Tools]] 3.5) and [http://www.linux-iscsi.org/builds/core-iscsi-dv/core-iscsi-dv-v1.0/README README]. * {{anchor|Core-iSCSI Tools}} Core-iSCSI Tools v3.5 (iSNS client, scripts, manual pages, example configuration files and documentation): [http://www.kernel.org/pub/linux/utils/storage/iscsi/core-iscsi-tools-v3.5.tar.bz2 <code>core-iscsi-tools-v3.5.tar.bz2</code>].<ref>{{cite web| url=http://groups.google.com/group/Core-iSCSI/browse_frm/thread/c530886d5247e913/#| title=core-iscsi-dv.sh and Core-iSCSI-tools v3.5 released| author=Nicholas Bellinger| work=Core-iSCSI mailing list| date=2006-07-11}}</ref> == See also == * [[Open-iSCSI]] * [[Diskless boot]] * [[Platforms]] * {{Target}} * [[Kernel-based Virtual Machine|KVM]] == Notes == {{Reflist}} == External links == * [http://groups.google.com/group/Core-iSCSI Core-iSCSI Mailing list] * [http://www.kernel.org/pub/linux/utils/storage/iscsi/HOWTO Core-iSCSI HOWTO] * [http://www.kernel.org/pub/linux/kernel/people/nab/iscsi-initiator-core/core-iscsi-v1.6.2.9.tar.bz2 Core-iSCSI v1.6] source code for Linux v2.6 * [http://www.kernel.org/pub/linux/utils/storage/iscsi/core-iscsi-tools-v3.5.tar.bz2 core-iscsi-tools-v3.5.tar.bz2]: iSNS client, scripts, manual pages, example configuration files and documentation [[Category:iSCSI]] [[Category:Initiators]]

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