Hi, On 10/07/2017 10:56 PM, Martin Eberhard Schauer wrote: > Package: iscsiuio > Version: 2.0.874-3~deb9u1 > Severity: wishlist > X-Debbugs-CC: debian-l10n-engl...@lists.debian.org > > the last paragraph of the package description [1] and its short > description sound strange to me. > > "This package is required to offload iSCSI onto these devices." > > Not being a native English speaker, I found [2]. Thus I believe that > "offload" and "onto" don't fit together.
I'm not a native speaker either, but the link you mentioned does actually use "offload onto" in the example. To quote your link [2] <http://dictionary.cambridge.org/de/worterbuch/englisch/offload#translations>: [Definition] get rid of something that you do not want by giving it to someone else [Example] I managed to offload some of our old furniture onto a friend who just bought a house. This does fit the package; iscsiuio enables offloading of the work required to process and generate iSCSI packets onto the network card itself. (Some network cards capable of iSCSI offloading don't require iscsiuio for that functionality to work, but those in the package description do.) The term "offload" is also used widely in similar contexts in the network stack, for example when it comes to calculating TCP checksums: https://en.wikipedia.org/wiki/TCP_offload_engine That said, I am open to wording improvements to help clarify this, but: > Perhaps > "You need this package|software to make these devices work with iSCSI"? Sorry, but this is completely wrong on a technical level. The devices we are talking about here are network cards (NICs). There have been drivers in the Linux kernel for these network cards for years now, you don't need iscsiuio to make them work at all. You also don't need iscsiuio to make iSCSI work over them: the standard software iSCSI stack on Linux will work perfectly fine over any network card. What iscsiuio does here is that it provides a part of the functionality required to have the network cards take over the processing of the iSCSI sessions. This means that the processing of data packets (reading and writing from/to iSCSI disks) is now not done by the kernel on the CPU, but done by the network card itself. This reduces the CPU load on the host system and improves performance with iSCSI. But you don't actually need to use those features of your network card if you just want to get iSCSI to work. If you want to go further into more detail, iscsiuio is actually a really ironic thing. The QLogic (formerly Broadcom) cards that iscsiuio supports are cards that for some reason unknown to me separate the actual network capabilities and the offloading capabilities. But they also only support the actual iSCSI protocol over TCP, but no other IP protocols (such as ARP or DHCP) that are actually required to successfully have a link. Therefore it is up to the software to provide DHCP / ARP functionality for the part of the card that handles the iSCSI offloading, which is kind of a reverse offloading for the ARP functionality. And the driver authors for these cards have decided that they want to provide that via a userspace daemon. In fact, once the offloaded iSCSI session over a QLogic/Broadcom card has been established and if you don't care about the ability to be able to reconnect in case the link goes down, you can actually shut down the iscsiuio daemon completely, you only need it while you're establishing the iSCSI session to provide ARP and possibly DHCP functionality. Also note that there are other networking cards that don't use this logic. The Chelsio cards that were first supported in Linux for iSCSI offloading don't separate the regular network interface from the offloading part, so there you can just configure the network interface normally and open-iscsi can directly tell the kernel driver to perform the offloading, without any need for iscsiuio. Hope that clarifies a bit what this package does. I'm open to improving the package description, but I do want to keep the work "offload" in a prominent position there, as that is the standard technical term in this field, and people who want to use that functionality will search for that word. Regards, Christian
