From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ahmed Kamal" Subject: Re: single disk reed solomon codes Date: Mon, 21 Jul 2008 10:40:06 +0300 Message-ID: <3da3b5b40807210040s72fdf458g44a1fe968088586e@mail.gmail.com> References: <3da3b5b40807190521x35477489sc06195bb182a4561@mail.gmail.com> <0cb201c8e9b2$a4272b20$0a00a8c0@ALDI2> <1216622923.6970.19.camel@s1.crocom.com.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-btrfs@vger.kernel.org To: "Tomasz Torcz" Return-path: In-Reply-To: <1216622923.6970.19.camel@s1.crocom.com.pl> List-ID: I definitely hope btrfs has this per-object "copies" property too. However, simply replicating the whole contents of a directory, wastes too much disk space, as opposed to RS codes On Mon, Jul 21, 2008 at 9:48 AM, Tomasz Torcz wrote: > Dnia 2008-07-19, sob o godzinie 17:18 +0200, Gerald Nowitzky pisze: > >> In the end, you would add very little security by the price of -at least- >> cutting half your write performance. Thus, I don't think there is any point >> in adding redundancy to single disk systems. > > ZFS can store multiple copies of data block within one disk. Using > your words, it's like "Intra-Disk-RAID1". After reading data, when > checksum shows it's corrupted, another copy (hopefully correct) is read > from other disk location. > This is adding security by the price of half storage capacity. Which > seems like a fair game, given todays 1,5TB HDDs. > > -- > Tomasz Torcz > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >