lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 31 Aug 2009 08:45:38 -0700 (PDT) From: david@...g.hm To: Pavel Machek <pavel@....cz> cc: George Spelvin <linux@...izon.com>, linux-doc@...r.kernel.org, linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org Subject: Re: raid is dangerous but that's secret (was Re: [patch] ext2/3: On Mon, 31 Aug 2009, Pavel Machek wrote: >> Actually, there is something the file system can do to make journaling >> safe on degraded RAIDs: make the (checksummed) journal blocks equal to >> the RAID stripe size. Or, equivalently, pad out to the RAID stripe >> size each commit. >> >> This sometimes leads to awkward block sizes, but while writing >> to any *one* stripe on a degraded RAID-5 endangers the others, you >> can write to *all* of them with the usual semantics. > > Well, that would work... but you'd also have to journal data, with the > same block size. Not exactly fast, but at least safe... > >> That's one thing I really like about ZFS: its policy of "don't trust >> the disks." If nothing else, simply telling you "your disks f*ed up, >> and I caught them doing it", instead of the usual mysterious corruption >> detectec three months later, is tremendoudly useful information. > > The more I learn about storage, the more I like idea of zfs. Given the > subtle issues between filesystem and raid layer, integrating them just > makes sense. note that all that zfs does is tell you that you already lost data (and then only if the checksumming algorithm would be invalid on a blank block being returned), it doesn't protect your data. David Lang -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists