Re: a (hopefully) simple newbie zfs query regarding available space
2009/8/9 John . > 2009/8/9 chris scott : > > > > > not a zfs thing is happens with all os and file systems. Basically HD > > manufacturers quote their capacities in base 10 ie 1 TB = 10 > bytes. > > File systems are calculated in binary therefore the calculation they use > is > > 1024 x 1024 x 1024 = 1099511627776. Slightly more as you can see. > > > > Therefore 1 GB is os terms is 1073741824 > > > > therefore hd capacity in GB is > > > > 1/1073741824 = 931.322575 > > > > The extra you see is it due to HD manufactures slightly over capacity the > > drives > > > > Hi, > > What I meant was, I was seeing 931MB instead of 1.6TB (2x1TB disks) > but this was because I didn't read about zfs properly (they recommend > 3 or more disks. In the man page for zpool it says: > > "A raidz group with N disks of size X with P parity disks can hold > approximately (N-P)*X bytes > [...] > The recommended number is between 3 and 9" > > so, I'll wait till I get an array before implementing zfs. In the > meantime, I'm using gconcat. Sorry for the noise. > > -- > John > ___ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to " > freebsd-questions-unsubscr...@freebsd.org" > ah did you do a zpool create tank ad0 then zpool attach tank ad1 type thing? if you did you have you have created a mirror to fix do a zpool dettach ad1 then a zpool add ad1 to create a stripe Having said that it not good practice to have no redundancy. You could comprise by putting your important data on a dedicated file system then setting copies to 2 or 3 ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: a (hopefully) simple newbie zfs query regarding available space
2009/8/9 chris scott : > > not a zfs thing is happens with all os and file systems. Basically HD > manufacturers quote their capacities in base 10 ie 1 TB = 10 bytes. > File systems are calculated in binary therefore the calculation they use is > 1024 x 1024 x 1024 = 1099511627776. Slightly more as you can see. > > Therefore 1 GB is os terms is 1073741824 > > therefore hd capacity in GB is > > 1/1073741824 = 931.322575 > > The extra you see is it due to HD manufactures slightly over capacity the > drives > Hi, What I meant was, I was seeing 931MB instead of 1.6TB (2x1TB disks) but this was because I didn't read about zfs properly (they recommend 3 or more disks. In the man page for zpool it says: "A raidz group with N disks of size X with P parity disks can hold approximately (N-P)*X bytes [...] The recommended number is between 3 and 9" so, I'll wait till I get an array before implementing zfs. In the meantime, I'm using gconcat. Sorry for the noise. -- John ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: a (hopefully) simple newbie zfs query regarding available space
2009/8/9 John . > Hello list > > I followed instructions for ZFS on > http://wiki.freebsd.org/ZFSQuickStartGuide, substituting ad6 and ad10 > (two new SATA3 1TB disks) for da0 da1 and da2 in the instructions. I > was surprised to see only 993GB in /tank/. Is this expected, or is it > user error? Also, these disks are completely unformatted. I expected > to do a newfs or something similar, and for it to take a bit of time! > > This is on a running 7.2-STABLE amd64 system. It is only these two > disks that I want as ZFS, the rest are UFS2 > > cheers > -- > John > ___ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to " > freebsd-questions-unsubscr...@freebsd.org" > not a zfs thing is happens with all os and file systems. Basically HD manufacturers quote their capacities in base 10 ie 1 TB = 10 bytes. File systems are calculated in binary therefore the calculation they use is 1024 x 1024 x 1024 = 1099511627776. Slightly more as you can see. Therefore 1 GB is os terms is 1073741824 therefore hd capacity in GB is 1/1073741824 = 931.322575 The extra you see is it due to HD manufactures slightly over capacity the drives ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: a (hopefully) simple newbie zfs query regarding available space
2009/8/9 John . : > Hello list > > I followed instructions for ZFS on > http://wiki.freebsd.org/ZFSQuickStartGuide, substituting ad6 and ad10 > (two new SATA3 1TB disks) for da0 da1 and da2 in the instructions. I > was surprised to see only 993GB in /tank/. Is this expected, or is it > user error? Also, these disks are completely unformatted. I expected > to do a newfs or something similar, and for it to take a bit of time! > > This is on a running 7.2-STABLE amd64 system. It is only these two > disks that I want as ZFS, the rest are UFS2 > > cheers > -- > John > I think I might have answered my own questionj - seems we need 3 or more disks for raidz - (n-p)*x gives 1TB usable. reliability isn't that important, and they are new disks. I suppose ccd would be better in this scenario? -- John ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
