On 03 Jan 2014, at 14:24 , Dinse, Gregg (NIH/NIEHS) [V] <[email protected]> wrote:
> Can you explain why you think RAID-0 The failure rate on modern hard drives is too high for me to be at all comfortable with RAID-0. The only RAID-0 device that I have I am pulling all the data off and have lost about 3% of the files on it due to read errors. I’ll be reformatting it as a RAID-5 as soon as I’ve gotten everything off I can. I was only using the RAID0 to store TV show caps and movie rips, but I made the mistake on thinking the data was easily replaceable or ephemeral. It was, but the time lost was significant. My current opinion is that RAID0 should never be used for anything other than temporary storage of working files. For example, if you have a large video project, keep your clips on a NAS or RAID5 (or 6, or 10) and then use a RAID0 as your scratch disk for processing that video and rendering. Copy the final product off the RAID0 as soon as you can to backups or other storage. Never rely on RAID0 for your data, nothing that is not transient in nature should be stored there. If you think, even for a second, that losing the data on a RAID0 would be more than a very slight inconvenience, don’t use it. > is a poor choice for the HDDs in my Mac Pro? I thought this would increase > both speed and capacity. Yes, it will, but there’s no error checking, there’s no redundancy, and not to start channeling Siracusa here, but if your raid is HFS+ then… well, no, just no. I think RAID-5 is a reasonable trade-off between speed and reliability. Of course, that still requires backups because [All together now], “RAID is not backup." > I realize there is no security (as with RAID-1), but I plan to do backups, so > hopefully that will provide some level of security. If you backup a file that has a write error you end up with a bad backup of that file. The issue with RAID0 especially with Macs isn that HFS+ is … well, not good. The larger disks get and the more files we throw at it, the less good it is. Yes, even with journaling. > The LaCie 5big comes as a 5-disk RAID-0 array (5 x 2-TB = 10-TB). For some > reason, their thunderbolt 5big only provides software RAID via OS X Disk > Utility. So my only other choice is RAID-1. I thought I might switch from a > single 5-disk RAID-0 to a 3-disk RAID-0 (for Time Machine backups) and a > 2-disk RAID-0 for something else (maybe even a different backup scheme). According to LaCie the 5big not only supports RAID5, but that is the default configuration, although they also refer to RAID0 as the default. <http://www.lacie.com/support/faq/faq.htm?faqid=10607> -- sometimes ascii is the best use of bandwidth... Tonya Engst _______________________________________________ MacOSX-talk mailing list [email protected] http://www.omnigroup.com/mailman/listinfo/macosx-talk
