si-ghan-bi wrote:You have a 10x2TB array in RAIDZ1?
You may read this:
http://www.zdnet.com/blog/storage/why-r ... n-2009/162
Also: RAID 5 and Uncorrectable Read Errors, and so on … but nothing relating to ZFS or scrub.
With a bunch of disks used for RAID-Z1 plus suitably frequent scrubbing, I imagine that:
- the probability of URE affecting a second disk during RAID-Z1 reconstruction is lower than
- the probability for a comparable bunch with RAID-5 without ZFS (with neither prior scrub nor prior read verification routines.
True? Or just my imagination?
Meantime I'm reading The RAID Reliability Anthology – Part 1 – The Primer (2010-08-30), which does include the magic word scrub …
Postscripts
How ZFS handles online replacement in a RAID-Z (theoretical) – interesting, but doesn't answer my probability question.
Calculators
Whilst bookmarking pages such as Free RAID Calculator - Caclulate RAID Array Capacity and Fault Tolerance., RAID Calculator - International Computer Concepts (ICC) and RAID 5 and Uncorrectable Read Errors I wished for a calculator to include ZFS-related options such as:
- RAID-Z1
- RAID-Z2
- RAID-Z3
- frequency of scrub
Such calculators are open to criticism but still, there's the wish.