[dm-devel] Does multipath require disabled write cache?
spelic at shiftmail.org
Sun Jul 20 21:20:07 UTC 2014
I am wondering if multipath requires a disabled write cache at the
We have some external SAS disks, for which the connection is flaky and
sometimes is lost and then they are detected again. Multipath seems
perfect for this situation.
However, when the disks are lost, I suppose resets are issued, which
might clear the write cache so that data located there might not be
committed (true? well at least on power loss this is true).
It would be great if multipath would issue a flush every N writes, and
then remember the last N writes and resubmit them when the path is
reestablished, so that there is again chance to flush them to stable
storage. (similar to DRBD epochs) However I don't know if this smart
mechanism is implemented.
Thanks for info
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