Date: Fri, 1 Jun 2012 10:35:25 -0500 From: Dan Nelson <dnelson@allantgroup.com> To: Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl> Cc: Kaya Saman <kayasaman@gmail.com>, Polytropon <freebsd@edvax.de>, freebsd-questions@freebsd.org Subject: Re: Anyone using freebsd ZFS for large storage servers? Message-ID: <20120601153525.GA16874@dan.emsphone.com> In-Reply-To: <alpine.BSF.2.00.1206011703450.3457@wojtek.tensor.gdynia.pl> References: <CACxnZKM__Lt9LMabyUC_HOCg2zsMT=3bpqwVrGj16py1A=qffg@mail.gmail.com> <alpine.BSF.2.00.1206011048010.2497@wojtek.tensor.gdynia.pl> <CAPj0R5%2BLcKUGijT17W6RXBz_KQxz5nZYP0vfPY3HNxNEyw0Eaw@mail.gmail.com> <alpine.BSF.2.00.1206011435430.20357@wojtek.tensor.gdynia.pl> <CAPj0R5KiUh3HFgbWCy8KDHhCA8L6-t5P85qFovDN%2Br9OHm90Og@mail.gmail.com> <20120601163520.f130cdcd.freebsd@edvax.de> <alpine.BSF.2.00.1206011703450.3457@wojtek.tensor.gdynia.pl>
next in thread | previous in thread | raw e-mail | index | archive | help
In the last episode (Jun 01), Wojciech Puchar said: > > and unbelievable narrow cases, when you don't have or can't access a > > backup (which you should have even when using ZFS), and you _need_ to do > > some forensic analysis on disks, ZFS seems to be a worse solution than > > UFS. On ZFS, you never can predict where the data will go. Add several > > disks to > > true. in UFS for example inodes are at known place, and flat structure > instead of "tree" is used. > > even if some sectors are overwritten with garbage then fsck can scan over > inodes and recover all that can be recovered. > > ZFS is somehow in that part similar to Amiga "Fast" File System. when you > overwrite a directory block (by hardware fault for example), everything > below that directory will disappear. You may not be even aware of it > until you need that data On the other hand, even on a single-disk pool, ZFS stores two copies of all metadata, so the chances of actually losing a directory block are extremely remote. On mirrored or RAIDZ pools, you have at least four copies of all metadata. -- Dan Nelson dnelson@allantgroup.com
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20120601153525.GA16874>