[tahoe-lafs-trac-stream] [tahoe-lafs] #1212: Repairing fails if less than 7 servers available

[tahoe-lafs]

#1212: Repairing fails if less than 7 servers available
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     Reporter:           |      Owner:  sickness
  eurekafag              |     Status:  new
         Type:  defect   |  Milestone:  1.8.1
     Priority:  major    |    Version:  1.8.0
    Component:  code-    |   Keywords:  reviewed regression repair news-
  network                |  needed
   Resolution:           |
Launchpad Bug:           |
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Comment (by gdt):

 I think sickness's desire for not having more than one share on a server
 blurs two things.   One is having adequate redundancy, and a behavior of
 adding shares s.t. a server has two (in the 9 servers present case) helps.
 But, when the 10th server is back on line, if it doesn't have a share,
 then repair should consider the file unhealthy and place a share on the
 10th server such that 10 servers have a distinct share.  Further the lease
 on the extra share probably shouldn't be renewed.

 If sickness also desires some form of storage efficiency, to avoid placing
 the 2nd share, then I think it's a misuse of servers-of-happiness and
 there should be some max-shares-per-server config, defaulting to infinite.

 This all becomes difficult in the middle, when you have a 3/10 encoding
 and 3 or 4 servers.  You want to set H to 3 or 4, but a share distribution
 of 7/1/1/1 isn't really ok - you want it to be more balanced.   But I
 think we should figure out if this is a a reliability concern or an
 efficiency concern and treat them separately.

-- 
Ticket URL: <http://tahoe-lafs.org/trac/tahoe-lafs/ticket/1212#comment:37>
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