From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============3541942719071843882==" MIME-Version: 1.0 From: Kumaraparameshwaran Rathnavel Subject: Re: [SPDK] BDEV & VBDEV Date: Fri, 21 Oct 2016 23:29:46 +0530 Message-ID: In-Reply-To: c41444c6-27f1-597b-89ba-9078d1fa7798@intel.com List-ID: To: spdk@lists.01.org --===============3541942719071843882== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Thanks Daniel. So in the virtual subsystem the example in the tree is mall= oc devices. So instead of that I can create my own subsystem like malloc d= evices right. Is there support for virtual subsystem from end to end . Say = that when I get a read command from kernel initiator the SPDK reads the dat= a n then sends it back to the initiator = Thanking you, = Param Sent from my iPhone > On 21-Oct-2016, at 11:18 PM, Daniel Verkamp = wrote: > = >> On 10/21/2016 06:31 AM, Kumaraparameshwaran Rathnavel wrote: >> Hi Guys, >> = >> What is the difference between BDEV and VBDEV ? >> = >> Thanking You, >> Param > = > Hi Param, > = > Regular bdevs expose raw block devices (NVMe namespaces, kernel block dev= ices via libaio, etc.). They typically interface with a hardware device tha= t needs to be polled periodically to check for completions. > = > A vbdev is a "virtual blockdev" that consumes one or more bdevs and produ= ces another set of bdevs. A vbdev can process each I/O and decide what to = do with it - for example, it could send each I/O to an underlying bdev, or = split a single request into multiple I/Os to several different bdevs to imp= lement features like RAID, or even encrypt writes and decrypt reads to add = a disk encryption layer. > = > We don't have any vbdev examples in the tree currently, but we plan to ad= d an example vbdev that will read partition tables from a disk and expose e= ach partition as another bdev that can be exposed as an iSCSI LUN or NVMe o= ver Fabrics namespace. > = > Thanks, > -- Daniel > _______________________________________________ > SPDK mailing list > SPDK(a)lists.01.org > https://lists.01.org/mailman/listinfo/spdk --===============3541942719071843882==--