i don´t know how sync is executed, but each write you send to a ssd make the ssd write period of life smaller if it´s just a READ command no problem, but a WRITE command (sync) is a problem for ssd a check (a sync without WRITE) could be nice... it just need tell us how many mirrors are unsync and how many bytes(sectors) in each mirror (fail disk if it´s not sync, start a resync, these features as a command line option...) 2011/2/7 Martin Cracauer <cracauer@xxxxxxxx>: > Roberto Spadim wrote on Mon, Feb 07, 2011 at 09:52:34PM -0200: >> i don?t know if exists, but maybe a internal mdadm command to check >> array (if have mirrors or ecc/checksum) with a limited speed (mb/s) >> read operation could help with periodic check (instead resync) > > I don't experience performance problems from this. Linux md seems to > be very good at putting the sync at a backburner when there is real > activity. Just today I benchmarked an array that was in progress of > building a raid5 (initial sync). Left most of the cycles to the > benchmark and took endless. That should be configureable, too (for > those who want the sync done with priority but can't kill activity), > but anyway my concern isn't performance. > > Martin > >> 2011/2/7 Martin Cracauer <cracauer@xxxxxxxx>: >> > I just got through the RebuildStarted event which seems to be >> > monthly. ?This is being triggered by my Debian config, but before I >> > nuke it I'd like to know a little more. >> > >> > If a real disk error happens during this rebuild on a raid5, would the >> > disk go into regular degraded mode or would it count as a double >> > fault? >> > >> > I also noticed that recently all the checks for all the arrays happen >> > simultaneously. ?That's bad because most of them share the same >> > physical disks. ?Am I imagining this or was the system smart enough to >> > do them one after another until recently? >> > >> > Do you do period checks? I get lots of device mismatches reported but >> > apparently that's normal if there's write activity. ?The whole thing >> > sound contra-productive to me and might panic new users. >> > >> > Martin >> > -- >> > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% >> > Martin Cracauer <cracauer@xxxxxxxx> ? http://www.cons.org/cracauer/ >> > -- >> > To unsubscribe from this list: send the line "unsubscribe linux-raid" in >> > the body of a message to majordomo@xxxxxxxxxxxxxxx >> > More majordomo info at ?http://vger.kernel.org/majordomo-info.html >> > >> >> >> >> -- >> Roberto Spadim >> Spadim Technology / SPAEmpresarial > > -- > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% > Martin Cracauer <cracauer@xxxxxxxx> http://www.cons.org/cracauer/ > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Roberto Spadim Spadim Technology / SPAEmpresarial -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
