Sunil and Saar - thanks for the quick replies!! Quick follow-up question: would the 11g asmcmd "md_backup" command also be able to quickly rebuild all of the disk header information without losing any data?
On 12/13/07, Saar Maoz <[EMAIL PROTECTED]> wrote: > > > To avoid confusion, the paragraph I wrote is in context of ASM's > management of superblock, not OCFS2. OCFS2 was already responded to by > Sunil in another reply. > > Regards, > > Saar. > > -- > __ _ _ __ _ _ _ _ ___ _____________________________ > (( /\\ /\\ ||) |\V/| /\\ /\\ >/ Consulting Software Engineer > _))//-\\//-\\||\ |||||//-\\\\//<_ Oracle Corporation > HQ: 650.50-mixOS WK: 510.222.4224 [EMAIL PROTECTED] 4op441 > \\\\\\\\50-64967\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ > ///Share your knowledge with others and compete with yourself/// > > > On Thu, 13 Dec 2007, Saar Maoz wrote: > > > Date: Thu, 13 Dec 2007 20:28:44 +0200 (Jerusalem Standard Time) > > From: Saar Maoz <[EMAIL PROTECTED]> > > To: Jeremy Schneider <[EMAIL PROTECTED]> > > Cc: [email protected] > > Subject: Re: [Ocfs2-users] superblock backups, ASM vs OCFS2 > > > > Jermey, > > > > In 11.1.0.7 (and beyond) we will have a backup of the disk header (the > first > > 4k). Prior to that, we have been able in most circumstances to > reconstruct > > the disk header using KFED. KFED will still be the tool to restore the > disk > > header going forward, it will just be a simpler, more reliable > procedure. > > > > Regards, > > > > Saar. > > > > -- > > __ _ _ __ _ _ _ _ ___ _____________________________ > > (( /\\ /\\ ||) |\V/| /\\ /\\ >/ Consulting Software Engineer > > _))//-\\//-\\||\ |||||//-\\\\//<_ Oracle Corporation > > HQ: 650.50-mixOS WK: 510.222.4224 [EMAIL PROTECTED] 4op441 > > \\\\\\\\50-64967\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ > > ///Share your knowledge with others and compete with yourself/// > > > > > > On Thu, 13 Dec 2007, Jeremy Schneider wrote: > > > >> Date: Thu, 13 Dec 2007 10:58:44 -0600 > >> From: Jeremy Schneider <[EMAIL PROTECTED]> > >> To: [email protected] > >> Subject: [Ocfs2-users] superblock backups, ASM vs OCFS2 > >> > >> [Also posted to Oracle-L] > >> > >> Just wondering, does anyone know much about "superblock" backups in ASM > vs > >> OCFS2? > >> > >> I ran into an interesting case a month or so back where someone had > >> accidentally tried to initialize their ASM disks with linux LVM... and > >> written the LVM headers to the disk. It was just a few bytes at the > very > >> top of the disk - but it was enough to totally hose ASM. Which started > me > >> thinking, "if this was a filesystem then I'd have a backup superblock > that > >> I > >> could recover". Who knows - maybe ASM has a backup of its header block > - > >> but it's all proprietary and if there's a tool that will recover an ASM > >> header then it's probably buried at Oracle support somewhere. > >> > >> Looks like OCFS2 includes superblock backups since this patchset: > >> http://lkml.org/lkml/2007/1/22/148 > >> > >> Not sure if ckfs will recover them but since it's open source it'd be > >> trivial to put together a utility that would recover a superblock. > >> > >> This seems to me to be a great reason to choose OCFS2 over > ASM. Recovering > >> a backup superblock is MUCH faster than recreating the entire volume > and > >> restoring data from backup!!! I don't even know if you could use dd to > try > >> to backup your ASM disk headers - since it's proprietary I don't know > >> what's > >> in those blocks. > >> > >> Anyone have any thoughts on this? Is there anything I'm missing here? > >> > >> Jeremy > >> > >> > >> -- > >> Jeremy Schneider > >> Chicago, IL > >> http://www.ardentperf.com/category/technical > >> > >> > > > _______________________________________________ > Ocfs2-users mailing list > [email protected] > http://oss.oracle.com/mailman/listinfo/ocfs2-users > > > _______________________________________________ > Ocfs2-users mailing list > [email protected] > http://oss.oracle.com/mailman/listinfo/ocfs2-users > > -- Jeremy Schneider Chicago, IL http://www.ardentperf.com/category/technical
_______________________________________________ Ocfs2-users mailing list [email protected] http://oss.oracle.com/mailman/listinfo/ocfs2-users
