yeah i use Raid 6 on large capacity drives when looking for redundancy and as much capacity as i can get. and always always a hot swap so it can start rebuild as soon as possible. it takes forever now to rebuild. -Ben
On Sat, Oct 17, 2009 at 10:09 PM, <[email protected]> wrote: > Storage capacity is a major factor here. For small disk sizes, there is > considerable value in SSDs. > > It becomes less of a no-brainer as you move up in size. At least for now. > > Sent from my Verizon Wireless BlackBerry > ------------------------------ > *From: * Sean Martin <[email protected]> > *Date: *Sat, 17 Oct 2009 16:26:26 -0800 > *To: *NT System Admin Issues<[email protected]> > *Subject: *Re: "Why RAID 5 stops working in 2009 | Storage Bits | > ZDNet.com" > > 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 >> ĸĸÃĸĸŋ While disks are incredibly reliable devices, they do fail. Our best >> data - >> ĸĸÃŋ from CMU and Google - finds that over 3% of drives fail each year in >> the >> ĸĸŋ first three years of drive life, and then failure rates start rising >> fast. >> >> ĸŋ With 7 brand new disks, you have ~20% chance of seeing a disk failure >> each >> ĸĸÃŋ year. Factor in the rising failure rate with age and over 4 years >> you are >> ĸĸŋĸŋ almost certain to see a disk failure during the life of those disks. >> >> ĸĸÃĸĸŋ But yoĸĸÂīre protected by RAID 5, right? Not in 2009. >> >> ĸĸÃŋ Reads fail >> ĸĸÃŋ SATA drives are commonly specified with an unrecoverable read error >> rate >> ĸĸÃĸĸŋ ĸŋ (URE) of 10^14. Which means that once every 100,000,000,000,000 >> bits, the >> ĸŋ disk will very politely tell you that, so sorry, but I really, truly >> ĸĸÃĸĸīt >> ĸĸŋ read that sector back to you. >> >> ĸŋ One hundred trillion bits is about 12 terabytes. Sound like a lot? >> Not in >> ĸĸÃĸĸŋ 2009. >> >> Disk capacities double >> ĸĸÃĸĸŋ Disk drive capacities double every 18-24 months. We have 1 TB >> drives now, >> ĸĸŋĸŋ&nbsĸĸÃŋ and in 2009ĸĸÃĸĸīll have 2 TB drives. >> >> ĸĸÃĸĸŋ ĸŋ With a 7 drive RAID 5 disk failure, yĸĸÃĸĸīll have 6 remaining 2 >> TB drives. >> ĸĸÃŋ As the RAID controller is busily reading through those 6 disks to >> ĸĸŋĸŋ reconstruct the data from the failed drive, it is almost certain it >> will >> ĸĸÃŋ see an URE. >> >> ĸĸŋ So the read fails. And when that happens, you are one unhappy >> camper. The >> ĸĸÃŋ message "weĸĸÃĸĸŋĸīt read this RAID volume" travels up the chain of >> command >> ĸĸŋĸŋ&nbsĸĸÃŋ until an error message is presented on the screen. 12 TB of >> your carefully >> ĸĸÃŋ ĸĸŋ protected - you thought! - data is gone. Oh, you diĸĸŋĸīt >> back it up to >> ĸĸÃŋ 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/> >> http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ >> >> > > > > > > > > > > > > > > > > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
