Date: Sun, 3 Nov 2013 08:36:40 -0800 From: Freddie Cash <fjwcash@gmail.com> To: Zenny <garbytrash@gmail.com> Cc: FreeBSD Stable <freebsd-stable@freebsd.org> Subject: Re: HDD-manufacture induced ZFS limitations Message-ID: <CAOjFWZ5drQ=TEbiBY1dqrQkSPf%2B=S1v7eegWAokHN-A3wU_v5A@mail.gmail.com> In-Reply-To: <CACuV5sB2JxFX16DYswh0SDo6AbCs3P0pdY0xwjnGT5Mi5%2BJDCw@mail.gmail.com> References: <CACuV5sB2JxFX16DYswh0SDo6AbCs3P0pdY0xwjnGT5Mi5%2BJDCw@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Nov 3, 2013 1:07 AM, "Zenny" <garbytrash@gmail.com> wrote: > > Hi: > > PROBLEM > > I came across a very weird situation because HDD-manufacturer counts > HDD space according to metric system instead of multiplication of 1024 > (2^10). This mismatches the space capacity between what OS filesystems > calculate HDD space. > > Secondly, each HDD manufacturer has different total byte size for what > they claim as the same sized HDDs. > > With the above two scenarios, it poses a nuisance to replace a > corrupted HDD with another HDD from another manufacturer even though > they claim that they are of the equal size, but differs by a few > bytes. Thus, zfs does not accept the new HDD. > > SOLUTION > > A way around is to create a sparse zfs dataset at the beginning, > according to the HDD-manufacturer defined metric system of HDD space > measurement at the power of 10 rather than 2^10. > > BUT ANOTHER PROBLEM > However, I came across another odd situation with the bsdinstaller > with FreeBSD 10-Beta2 which has an option to install root in zfs. The > bsdinstaller script is flawless as it is. But it does not address the > disksize mismatch problem as stated above. Any workaround will be > appreciated! > > It would be a nice feature if the new bsdinstaller in FreeBSD10 allows > the user first to make a sparse zfs dataset before installing root in > zfs. Thanks! The workaround is simple: create a partition that starts at 1 MB and leaves 1 MB free at the end of the disk. However, that workaround is no longer needed, as ZFS v22-ish introduced a similar workaround internally. So it's possible to use while disks that differ in size by 1MB or two without any issue.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAOjFWZ5drQ=TEbiBY1dqrQkSPf%2B=S1v7eegWAokHN-A3wU_v5A>