[Twg] [Discuss] T10 End-to-End Data Integrity HLD

[Alexey Lyashkov]

John,

Why not? HCA provide a T10 checksumming when obdfilter (osd) submit a IO request - so it's before a call bio_done() function and before send a reply to client.
so we may don't want a commit as HCA verify a checksum and it's correct.


PS. Andrew - please add that clarification to the document.
On Apr 21, 2012, at 03:22, Johann Lombardi wrote:

> Hi Alexey,
> 
> On Saturday, April 21, 2012, Alexey Lyashkov wrote:
> you are wrong. It's Andrew HLD. possible it isn't clear - but per internal discussion, server isn't validate checksum before HCA. Using a HCA to checksum validation and provide end to end integrity checks - main idea of using T10 in lustre.
> per my previous comment server validation isn't need - because client will resend IO request in both cases - checksum error or real IO error.
> 
> This means that you can't use asynchronous journal commit in conjunction with T10, right?
> 
> Johann

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