Re: Help: very slow software RAID 5.
Dean S. Messing wrote: I don't see how one would do incrementals. My backup system uses currently does a monthly full backup, a weekly level 3 (which saves everything that has changed since the last level 3 a week ago) and daily level 5's (which save everything that changed today). Rsync is fantastic tool for incremental backups. Everything that didn't change can be hardlinked to previous entry. And time of performing the backup is pretty much neglible. Essentially - you have equivalent of full backups at almost minimal time and space cost possible. - 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
Re: Help: very slow software RAID 5.
Dean S. Messing wrote: I have also discovered smartctl and have read that if the short smartctl tests are run daily and the long test weekly that the chances of being caught with my pants down are quite low, even in a two disk RAID-0 config. What is your opinion? There's a good paper on using smartctl to predict the health of disks, and if you can't find it I probably have a copy somewhere, since I gave a presentation on RAID issues which included it. But the basic premise was that if you see errors of certain types, the drives are likely to fail soon. It did *not* say that absent these warnings the drives were unlikely to fail, un fact most drives which did fail did so without warning. So for about 90% of the failures there is no warning. I had servers a few years ago, running 6TB/server, on lots of small fast drives, and I concluded that the predictive value of SMART was so small that it didn't justify looking at the reports. Take that as my opinion, assume that drives fail without warning. I'm getting around to replying to several things you have said in various posts, so that people who are threading answers will be happy... -- bill davidsen [EMAIL PROTECTED] CTO TMR Associates, Inc Doing interesting things with small computers since 1979 - 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
Backups w/ rsync (was: Help: very slow software RAID 5.)
Michal Soltys writes: : Dean S. Messing wrote: : : I don't see how one would do incrementals. My backup system uses : currently does a monthly full backup, a weekly level 3 (which : saves everything that has changed since the last level 3 a week ago) and : daily level 5's (which save everything that changed today). : : : Rsync is fantastic tool for incremental backups. Everything that didn't : change can be hardlinked to previous entry. And time of performing the : backup is pretty much neglible. Essentially - you have equivalent of : full backups at almost minimal time and space cost possible. It has been some time since I read the rsync man page. I see that there is (among the bazillion and one switches) a --link-dest=DIR switch which I suppose does what you describe. I'll have to experiment with this and think things through. Thanks, Michal. Dean P.S. I changed the Subject: to reflect the new subject. Not sure if that starts a new thread or not. - 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
