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How multi-disk failures happen

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Re: How multi-disk failures happen

#91
post #72

Earlier quoted context omitted.

> it isn't quite like one is the successor of the other. Given the current price of hard drives, I don't get how "twice the parity space" can even matter. Furthermore, modern RAID controllers perform almost exactly the same using RAID-5 or RAID-6 (verified on most 3Ware, LSI, Adaptec and Areca controllers). So yes, RAID-6 definitely is RAID-5 successor. > how to deal with that scenario. RAID is not an alternative to…

RAID-6 is in no universe a RAID-5 successor. Simplifications of enterprise needs and risk tolerances and compromise acceptance is sophistry. It is telling enough that despite the bluster of some on Hacker News, major storage vendors (ergo - people who know much more than you) still make RAID-5 the default. Maybe they just haven't read the news. Regarding the backup -- yeah, no kidding. That was the point. If the argu…

Apparently you're new to the web forums and aren't aware that different posts from different people may display only partial views of varying opinions, conflating a couple of my answers to different questions as one happily, and putting in someone else's answers with it for good measure. I, for instance, made no comment in this thread about proper hot spare policy.

About RAID-5: some major storage vendors still use it for smaller arrays. Some other don't use it anymore (NetApp, DDN come to mind). The notion that RAID-5 isn't fit for arrays of large capacity drives doesn't come from me and is hardly new. You don't need any links as obviously you know all about this already.

I've set up my first terabyte SAN in the 90s back when it used to fill a whole rack, 9 GB micropolis drives where hot and SSA was the new interconnect, but I probably know less about storage than you.

Re: How multi-disk failures happen

#92
post #91

Earlier quoted context omitted.

RAID-6 is in no universe a RAID-5 successor. Simplifications of enterprise needs and risk tolerances and compromise acceptance is sophistry. It is telling enough that despite the bluster of some on Hacker News, major storage vendors (ergo - people who know much more than you) still make RAID-5 the default. Maybe they just haven't read the news. Regarding the backup -- yeah, no kidding. That was the point. If the argu…

Apparently you're new to the web forums and aren't aware that different posts from different people may display only partial views of varying opinions, conflating a couple of my answers to different questions as one happily, and putting in someone else's answers with it for good measure. I, for instance, made no comment in this thread about proper hot spare policy. About RAID-5: some major storage vendors still use i…

Ah, the grizzled vet angle. The bit about me being new to the web is particularly adorable, especially given that I prefaced it by referring to other people (ergo, there was no confusion). When you have many logical volumes suddenly you can make choices like "does this necessitate the extra protection of RAID-6, given the compromises"? And people are making that choice to this day, and no one is saying "Oh look, there's RAID-6 which is the newer version of RAID-5 so it's my default choice".
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