On Fri, 2012-05-04 at 18:32 +0200, Christian Thaeter wrote: > Am Fri, 04 May 2012 17:45:21 +0200 > schrieb Haldun ALTAN <[email protected]>: > > > Well that was no more, for a long time, about Grand'ma proxy but > > about RAID > > > > May be this not the exact place to talk about RAID but indirectly > > offers a better use of cinelerra. I think :)) > > > > I just wanted to send a link about a very good tuto on how to RAID on > > ubuntu or others. It's just like the vidéo but very much more > > specifique. > > > > http://www.dedoimedo.com/computers/linux-raid.html > > apart from that tutorial, here are some tips for the raid level and > setup from my experience: > > for anything valuable (aka, your work) you want raid10 > with 3 or more drives. Thats not mentioned on the tutorial above but the > linux kernel can do raid10 since quite some time.
You can use RAID 10 on only 2 drives. > > This gives fast read speed, average write speed and redundancy on the > cost of 50% storage utilization. Speeds scale up as more drives you add. > > If you have only 2 Drives then choose Raid1, Performance and safety is > comparable to the Raid10 above. This is not the case. Yes you get the safety but no you don't get the performance. Linux RAID 1 only reads from a single disk, so the performance is comparable to a single drive. It was thought at one time that Linux RAID 1 did parallel reads, but this is false. I have personally done the benchmarking and my findings were conclusive. Plus you can find modern documentation to support my findings. If you seek redundancy and performance, use RAID 10. Linux RAID 10 is supported on as few as 2 drives. > If you have a fast computer with lots of RAM and lots of HDD's (4+) > then you may try to evaluate raid5 or raid6, but be aware that write > speeds are quite low and benchmark this before you using it seriously. > Reading scales well with the number of disks you have. Makes a good > vault for archiving files but might be too slow for a working area > (considering video work). Anyways this once worked for me. > > Finally stay away from Raid0, it brings double (or more) the speed for > double (or more) the risk. HDD's *WILL* fail eventually, its only matter > of time and Murphy's law tells this happens when you are least expect > it! This makes only sense for data you can *extremely* easy recover like > volatile cache files (Background rendering), Files you grabbed from a > cam and which are still available on a fast medium (no you don't want to > grab all tapes again!). For anything else, don't even consider it. > > Don't forget to make regular Disk checks (regular badblocks > (readonly) checks and then Raid-resyncs with mdadm in daemon mode) > which will try to repair damaged data. Having a smartd running is nice > to find out about if one of your drives will fail soon in few cases, > but doesn't substitute for the disk checks above as smartchecks don't > enforce a repair of damaged data and abort on the first found error, > leaving any potential bad data ahead undiscovered. > > And finally: RAID redundancy is only an insurance against Harddisk > failures but does *not* substitute for a backup, one manual mishap > destroying data can not be undone. > > Christian > > > > > Hope helps. > > > > Haldun. > > > > _______________________________________________ > > Cinelerra mailing list > > [email protected] > > https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra > > _______________________________________________ > Cinelerra mailing list > [email protected] > https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
