Jeff Breidenbach ([email protected]) wrote on 17 January 2006 00:45: >Is this a real issue or ignorable Sun propoganda? > >-----Original Message----- >From: I-Gene Leong >Subject: RE: [colo] OT: Server Hardware Recommendations >Date: Mon, 16 Jan 2006 14:10:33 -0800 > >There was an interesting blog entry out in relation to Sun's RAID-Z >talking about RAID-5 shortcomings: > >http://blogs.sun.com/roller/page/bonwick?entry=raid_z > >It sounds to me like RAID-1 would also be vulnerable to the write hole >mentioned inside.
The write-hole exists ONLY when the machine stops without a proper shutdown AND with an incomplete array (eg. one disk out of the array in a raid5). Sometimes this happens when the machine crashes or power goes down and on reboot one disk fails. If I understand Sun's marketing ZFS always writes full stripes in all disks, which means the array is never dirty. Therefore the write-hole indeed doesn't exist. The problem with the argument is that the write-hole is not so big of a problem in a well-behaving server because the probability of a crash and an incomplete array happening simultaneously is very small, so Sun's feature is not so important. - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
