Don't make me pull the prior art lever... Put down the trademarked words and nobody gets hurt.
-ASB: http://XeeSM.com/AndrewBaker On Sat, Oct 17, 2009 at 8:31 PM, Andrew Levicki <[email protected]>wrote: > Indeed®™! > > 2009/10/18 Sean Martin <[email protected]> > > I dont think that's necessarily true. If you were to do a cost-benefit >> analysis between traditional 15k drives and SSDs (or EFDs), you might be >> surprised what you find. >> >> Take an Exchange server that experiences an incredible amount of read IO >> at the information store. You might need 10 traditional spindles to meet >> demand, but only 2 SSDs. If the 15k drives cost $1000 a piece, and the SSDs >> cost $5000 a piece, it might make more sense to go the SSD route. Obviously >> storage capacity needs to be taken into consideration as well. >> >> - Sean >> >> On Oct 17, 2009, at 3:48 PM, [email protected] wrote: >> >> We need prices to fall significantly to reap the benefits of the sizes we >> need. >> >> Sent from my Verizon Wireless BlackBerry >> ------------------------------ >> *From: * Andrew Levicki <[email protected]> >> *Date: *Sat, 17 Oct 2009 19:12:41 +0100 >> *To: *NT System Admin Issues<[email protected]> >> *Subject: *Re: "Why RAID 5 stops working in 2009 | Storage Bits | >> ZDNet.com" >> >> In my opinion, we're on the cusp of seeing solid state storage becoming >> the norm and we will be able to put hard drives out to pasture or use them >> more for backups than tapes. >> Although we have much faster hard disks nowadays than ever, it's amazing >> that we are still at the behest of such a mechanical device for our mission >> / business critical data. Solid state FTW. >> >> Regards, >> >> Andrew >> >> 2009/10/17 Angus Scott-Fleming < <[email protected]>[email protected] >> > >> >>> Scaremongering, or legitimate things to worry about? Lots of the >>> "Talkback" >>> comments are that ZDNet is over the top these days, but it seems to me >>> he's got >>> some legitimate points. >>> >>> ------- Included Stuff Follows ------- >>> Why RAID 5 stops working in 2009 | Storage Bits | <http://ZDNet.com> >>> ZDNet.com >>> >>> Disks fail >>> ÿÿ While disks are incredibly reliable devices, they do fail. Our best >>> data - >>> ÿÿ from CMU and Google - finds that over 3% of drives fail each year in >>> the >>> ÿ first three years of drive life, and then failure rates start rising >>> fast. >>> >>> ÿ With 7 brand new disks, you have ~20% chance of seeing a disk failure >>> each >>> ÿ year. Factor in the rising failure rate with age and over 4 years you >>> are >>> ÿÿ almost certain to see a disk failure during the life of those disks. >>> >>> ÿÿ But yoÿ´re protected by RAID 5, right? Not in 2009. >>> >>> ÿ Reads fail >>> ÿ SATA drives are commonly specified with an unrecoverable read error >>> rate >>> ÿÿ ÿ (URE) of 10^14. Which means that once every 100,000,000,000,000 >>> bits, the >>> ÿ disk will very politely tell you that, so sorry, but I really, truly >>> caÿ´t >>> ÿ read that sector back to you. >>> >>> ÿ One hundred trillion bits is about 12 terabytes. Sound like a lot? >>> Not in >>> ÿÿ 2009. >>> >>> Disk capacities double >>> ÿÿ Disk drive capacities double every 18-24 months. We have 1 TB drives >>> now, >>> ÿÿ ÿ and in 2009 wÿ´ll have 2 TB drives. >>> >>> ÿÿ ÿ With a 7 drive RAID 5 disk failure, yÿÿ´ll have 6 remaining 2 TB >>> drives. >>> ÿÿ As the RAID controller is busily reading through those 6 disks to >>> ÿÿ reconstruct the data from the failed drive, it is almost certain it >>> will >>> ÿ see an URE. >>> >>> ÿ So the read fails. And when that happens, you are one unhappy camper. >>> The >>> ÿÿ message "we cÿÿ´t read this RAID volume" travels up the chain of >>> command >>> ÿÿ ÿ until an error message is presented on the screen. 12 TB of your >>> carefully >>> ÿÿ ÿ protected - you thought! - data is gone. Oh, you didÿ´t back it up >>> to >>> ÿÿ tape? Bummer! >>> >>> --------- Included Stuff Ends --------- >>> More here with links: <http://blogs.zdnet.com/storage/?p=162> >>> http://blogs.zdnet.com/storage/?p=162 >>> >>> >>> -- >>> Angus Scott-Fleming >>> GeoApps, Tucson, Arizona >>> 1-520-290-5038 >>> +-----------------------------------+ >>> >> ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
