Date: Wed, 08 Jul 2015 17:20:35 +0100 From: Matthew Seaman <m.seaman@infracaninophile.co.uk> To: freebsd-fs@freebsd.org Subject: Re: Speeding up resilvering Message-ID: <559D4DD3.10903@infracaninophile.co.uk> In-Reply-To: <559D3380.8050703@sentex.net> References: <559D2AB6.5070007@FreeBSD.org> <559D2C7C.6060201@denninger.net> <559D3167.1000705@infracaninophile.co.uk> <559D3236.1060102@denninger.net> <559D3380.8050703@sentex.net>
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This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --060uth7oEQeKXehX28voNVE36nwF4EXRs Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 07/08/15 15:28, Mike Tancsa wrote: >> Look at the IO saturation on the disk channel(s) involved with either >> > systat -vm or iostat. If the channel is saturated then there's noth= ing >> > you can do in terms of tuning; the question then turns to why actual= I/O >> > performance is so poor and has to be addressed there. > I had one server that was taking ages, and it turned out to be the > controller, not the disk that was hosed. As Karl suggested, take a look= > at the throughput on gstat. Is anyone disk or groups of disks lagging > far behind on write speeds ? In my case, it was a very obvious and > glaring outlier. Thanks for the suggestions. I've been playing with gstat et al, and as far as I can tell, all the drives are behaving reasonably well. I'm certainly getting 90-100% capacity (mostly reads) continually on the original drives whilst the new one (mostly writes) seems to go in bursts. Which is pretty much what I'd expect when resilvering a RAIDZ. So, having exhausted that, I actually sat down and timed what progress it was making rather more carefully. Turns out my impression that applying the sysctl tweaks I mentioned previously had little effect was wrong. Current projection is about 50h total to do the resilvering, which is much, much better than the approx 12days I was expecting previously. In fact, that's pretty much inline with what I'd expect from this hardware. Cheers, Matthew --060uth7oEQeKXehX28voNVE36nwF4EXRs Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBCgAGBQJVnU3TAAoJEABRPxDgqeTnv8AP/jYepeX0oqLGnpr8kCEbyJOM ZYyKNMqo8li86H7nyMC4gpOBd4nbrfZt7mr7phqujXTTT9oVRFL4aD6biFxmQWMJ oFmNr2btAJWKn8XneYUyJDFEPRb/4hBaLTshuDTLXygUCLf5lkjhMEcASU1EwJQf BVpAWf3T/nPT5ZhaWsL8H/mp+dgGb2Zn72SBjeXjBE7hQe02Ay4q/s9nZ9emhi1z WG8f0khUxHu45DP3coHnQpssTYTiNeT5X1S1h6dHXxDoY+3NrYFCE4MmP9/YWw7I pPtSqiXa0Val+0Tt0yVWuvswjrZxTPvrgBs+7zbclhmypfK1sK06d8rITh1xGkv8 7YDRl3o1g8a+Ef7TwFN7uhShREeJMbTlGRbi4L3IgYs/FGyla/qM2D2EhVy/X4wH DI+YI+HKlTl7peI8P69mFjMAvUQdHkdYLaumzZoJDfiuHXeCLqo81GdlDkXXsYA+ Rq0XIfkeAq7WOUmv7v/vXwooeHEIEVrO+dQJy6ytv9Z3Xr3YNs464sEq8lnjWehn ZUgfyJkgwJVXELoR3xMgZJoXNVEvHYeorIrPQqRW+mGb/gRcnPYN8Wh08QkG4z0u mwYbr5sd0fF+BqXkVIEH/6xrogW2Bo/0zyu55woiW2kRFFfYk2no0as2/5wHHIBA fowqAS61LzIy7MgpFd74 =72FI -----END PGP SIGNATURE----- --060uth7oEQeKXehX28voNVE36nwF4EXRs--
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