Date: Fri, 7 Feb 2014 16:41:56 -0600 From: Dustin Wenz <dustinwenz@ebureau.com> To: Mark Felder <feld@freebsd.org> Cc: "<freebsd-fs@freebsd.org>" <freebsd-fs@freebsd.org> Subject: Re: Using the *real* sector/block size of a mass storage device for ZFS Message-ID: <8B5D8D0C-ADDE-49B3-87A9-DE1105E32BF9@ebureau.com> In-Reply-To: <1391808195.4799.80708189.5CAD8A4E@webmail.messagingengine.com> References: <1487AF77-7731-4AF8-8E44-FF814BB8A717@ebureau.com> <1391808195.4799.80708189.5CAD8A4E@webmail.messagingengine.com>
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Thanks for the information! I'm curious as to why gnop is the best way to accomplish this... FreeBSD = 10 seems to automatically set ashift: 12 when a new vdev is created. I = definitely appreciate the control that gnop provides, however. Am I correct in assuming that it is absolutely impossible to convert an = existing ashift:9 vdev to ashift:12? Some of my pools are approaching = 1PB in size; transferring the data off and back again would be = inconvenient. I suppose I should just be thankful that ZFS is warning me about this = now, before I need to build any really large storage pools.=20 - .Dustin On Feb 7, 2014, at 3:23 PM, Mark Felder <feld@freebsd.org> wrote: >=20 >=20 > On Fri, Feb 7, 2014, at 14:44, Dustin Wenz wrote: >> We have been upgrading systems from FreeBSD 9.2 to 10.0-RELEASE, and = I'm >> noticing that all of my zpools now show this status: "One or more = devices >> are configured to use a non-native block size. Expect reduced >> performance." Specifically, each disk reports: "block size: 512B >> configured, 4096B native". >>=20 >> I've checked these disks with diskinfo and smartctl, and they report = a >> sector size of 512B. I understand that modern disks often use larger >> sectors due to addressing limits, but I'm unsure how ZFS can disagree >> with these other tools. >>=20 >> In any case, it looks like I will need to rebuild every zpool. There = are >> many thousands of disks involved and the process will take months (if = not >> years). How can I be I sure that this is done correctly this time? = Will >> ZFS automatically choose the correct block size, assuming that it's >> really capable of this? >>=20 >> In the meantime, how can I turn off that warning message on all of my >> disks? "zpool status -x" is almost worthless due to the extreme = number of >> errors reported. >>=20 >=20 > ZFS is doing the right thing by telling you that you should expect > degraded performance. The best way to fix this is to use the gnop = method > when you build your zpools: >=20 > gnop create -S 4096 /dev/da0 > gnop create -S 4096 /dev/da1 > zpool create data mirror /dev/da0.nop /dev/da1.nop >=20 > Next reboot or import of the zpool will use the regular device names > with the correct ashift for 4K drives. >=20 > The drive manufacturers handled this transition extremely poorly. > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org"
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