Glenn Lagasse wrote: > Hi caimaniacs, > > Given this post from Adam, should we consider enabling dedup when > creating the root pool during install? Or at the very least enabling it > on the created user's home directory? > > Thoughts? >
We can consider anything, but to make decisions requires data on the benefits and costs. Lack of data is why we haven't done anything with other, older ZFS options, such as compression or copies. Dave > > > ------------------------------------------------------------------------ > > Subject: > Re: [zfs-discuss] will deduplication know about old blocks? > From: > Adam Leventhal <ahl at eng.sun.com> > Date: > Wed, 09 Dec 2009 09:43:15 -0800 > To: > Kjetil Torgrim Homme <kjetilho at linpro.no> > > To: > Kjetil Torgrim Homme <kjetilho at linpro.no> > CC: > zfs-discuss at opensolaris.org > > > Hi Kjetil, > > Unfortunately, dedup will only apply to data written after the setting is > enabled. That also means that new blocks cannot dedup against old block > regardless of how they were written. There is therefore no way to "prepare" > your pool for dedup -- you just have to enable it when you have the new bits. > > Adam > > On Dec 9, 2009, at 3:40 AM, Kjetil Torgrim Homme wrote: > >> I'm planning to try out deduplication in the near future, but started >> wondering if I can prepare for it on my servers. one thing which struck >> me was that I should change the checksum algorithm to sha256 as soon as >> possible. but I wonder -- is that sufficient? will the dedup code know >> about old blocks when I store new data? >> >> let's say I have an existing file img0.jpg. I turn on dedup, and copy >> it twice, to img0a.jpg and img0b.jpg. will all three files refer to the >> same block(s), or will only img0a and img0b share blocks? >> >> -- >> Kjetil T. Homme >> Redpill Linpro AS - Changing the game >> >> _______________________________________________ >> zfs-discuss mailing list >> zfs-discuss at opensolaris.org >> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > > > -- > Adam Leventhal, Fishworks http://blogs.sun.com/ahl > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > > > ------------------------------------------------------------------------ > > _______________________________________________ > caiman-discuss mailing list > caiman-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/caiman-discuss
