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On Sat, Jan 7, 2012 at 7:36 PM, Pandu Poluan <pandu@××××××.info> wrote: |
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> On Jan 8, 2012 12:43 AM, "Michael Mol" <mikemol@×××××.com> wrote: |
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>> On Sat, Jan 7, 2012 at 11:35 AM, Pandu Poluan <pandu@××××××.info> wrote: |
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>> > On Jan 7, 2012 8:44 PM, "victor romanchuk" <rom@××××××××××.net> wrote: |
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>> >> |
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>> >> Konstantinos Agouros wrote, at 01/07/2012 03:51 PM: |
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>> >> > since xen got into the mainstream kernel the way to go is to use |
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>> >> > gentoo-sources for dom0 and the domUs. However the blktap modules are |
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>> >> > not |
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>> >> > there. Is there any way to get this to work? |
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>> >> |
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>> >> blktap drivers were excluded from kernel mainline since 3.x, these two |
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>> >> threads |
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>> >> from xen-users mailing list might put some light in that context: |
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>> >> |
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>> >> |
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>> >> |
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>> >> http://old-list-archives.xen.org/archives/html/xen-users/2011-07/msg00637.html |
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>> >> |
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>> >> |
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>> >> http://old-list-archives.xen.org/archives/html/xen-users/2011-10/msg00065.html |
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>> >> |
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>> >> the latest sys-kernel/xen-sources containing working blktap (not |
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>> >> blktap2) |
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>> >> is |
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>> >> 2.6.38 (this is buggy from my point of view; i'm still sitting on |
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>> >> 2.6.34-r5 for |
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>> >> production installations) |
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>> >> |
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>> > |
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>> > Can someone shed a light on the importance of blktap, i.e., why one |
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>> > would |
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>> > want to use it when -- as someone explained in the first email thread |
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>> > you |
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>> > gave -- blkfront+blkend is enough for paravirtualization? |
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>> |
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>> Reading through the linked threads, it sounds like the benefit stems |
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>> from being able to shim things in between the front and back ends. |
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>> |
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>> You might want that for any number of reasons: |
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>> * a block encryption layer |
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>> * a metering layer |
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>> * a read/write masking layer |
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>> * an intercept to have the block device exist on (or be mirrored to) |
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>> on another system. |
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>> |
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>> etc. |
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>> |
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> |
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> Ah yes, of course. |
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> |
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> One of the threads also mentioned that blktap might be better implemented in |
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> userspace. |
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|
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Well, there's that, too. For a while, there's been a long push in |
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Linux to get anything that could remotely reasonably be done in |
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userspace out of kernelspace. |
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|
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-- |
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:wq |
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