> >On 28-Jan-07, at 7:59 AM, [EMAIL PROTECTED] wrote: > >> >>> >>> On 27-Jan-07, at 10:15 PM, Anantha N. Srirama wrote: >>> >>>> ... ZFS will not stop alpha particle induced memory corruption >>>> after data has been received by server and verified to be correct. >>>> Sadly I've been hit with that as well. >>> >>> >>> My brother points out that you can use a rad hardened CPU. ECC should >>> take care of the RAM. :-) >>> >>> I wonder when the former will become data centre best practice? >> >> Alpha particles which "hit" CPUs must have their origin inside said >> CPU. >> >> (Alpha particles do not penentrate skin, paper, let alone system cases >> or CPU packagaging) > >Thanks. But what about cosmic rays?
I was just in pedantic mode; "cosmic rays" is the term covering all different particles, including alpha, beta and gamma rays. Alpha rays don't reach us from the "cosmos"; they are caught long before they can do any harm. Ditto beta rays. Both have an electrical charge that makes passing magnetic fields or passing through materials difficult. Both do exist "in the free" but are commonly caused by slow radioactive decay of our natural environment. Gamma rays are photons with high energy; they are not capture by magnetic fields (such as those existing in atoms: electons, protons). They need to take a direct hit before they're stopped; they can only be stopped by dense materials, such as lead. Unfortunately, natural occuring lead is polluted by pollonium and uranium and is an alpha/beta source in its own right. That's why 100 year old lead from roofs is worth more money than new lead: it's radioisotopes have been depleted. Casper _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
