jwcolby
jwcolby at colbyconsulting.com
Thu Jul 22 12:55:41 CDT 2010
Well... I already have three TB drives, two full, one half full. John W. Colby www.ColbyConsulting.com Michael Bahr wrote: > Yeah but we are not running a server farm. :-P > > Mike... > >> Or... for 400$ plus parts I already have: >> >> MB (6 sata ports) Have it >> Processor Have it >> Memory Have it >> PS Have it >> (3) 1T drives Have it (movies installed) >> (7) 640G drives Have it >> >> Plus: >> >> (1) 4 port PCI Express card $90 >> (1) 16 drive unraid license $119 >> (1) 1TB parity drive $100 >> >> Case $90 >> http://www.newegg.com/Product/Product.aspx?Item=N82E16811219020&cm_re=4u_rackmount_case-_-11-219-020-_-Product >> >> Total: $400 for for ~7 terabytes usable. >> >> ;) >> >> John W. Colby >> www.ColbyConsulting.com >> >> >> Drew Wutka wrote: >>> A few months ago, saw a network capable RAID 1 hard drive setup for >>> ~$200, without the drives. Just a box with a network port. Terrabyte >>> drives are getting pretty cheap, so you could get a networked mirrored >>> 1+ terabyte setup for about 400. >>> >>> Drew >>> >>> -----Original Message----- >>> From: accessd-bounces at databaseadvisors.com >>> [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Michael Bahr >>> Sent: Wednesday, July 21, 2010 12:42 PM >>> To: Access Developers discussion and problem solving >>> Subject: Re: [AccessD] Google's Disk Failure Experience >>> >>> Well, I can see your point that only ripping DVD's takes 2 minutes each >>> and you do not need them anymore. But for me I record OTA/cable HD >>> shows >>> and uncut movies and cut out the commercials and archive them. Now I >>> have >>> whole seasons worth of shows and movies. I save money buy not buying >>> the >>> Blu-Ray disks ($30-$60 for each season or movie). So yes it is >>> important >>> to me to have a backup as these are not reproducible. A seperate media >>> server setup as raid 1 does fit my needs. >>> >>> Mike... >>> >>>> >How much is your time worth? >>>> >>>> This is a classic case of insufficient analysis... >>>> >>>> The cost is not the cost of the drive. It is the cost of the drive >>> (twice >>>> the drives), plus the >>>> cost of the SATA ports (twice) plus the cost of the power supply >>> (twice >>>> the disk current - 12v), >>>> plus the cost of electricity to run the disks (twice the electricity) >>> plus >>>> the cost of a case big >>>> enough to handle enough drives (twice as large disk cage) plus... >>>> >>>> Of course all my "twices" are on a "per disk used" basis, not a total >>>> system cost and I understand >>>> the difference. >>>> >>>> Furthermore, my time isn't the cost of my time to rip 200 dvds, it is >>> the >>>> cost of my time to rip 200 >>>> dvds divided by the probability of losing 2 disks at the same time. >>>> >>>> I ripped my drives as I wanted to watch them, so it was an incremental >>>> cost accumulated over time. >>>> The actual time is about 2 minutes per dvd. 200 dvds per drive is an >>>> actual cost of 200 minutes to >>>> fill a drive. Would I actually rerip all of the disks? No because >>> many >>>> of them are for my kids who >>>> are now older and don't even watch those disks any more, not to >>> mention >>>> the disks I ripped that I >>>> just don't care about. >>>> >>>> HOWEVER... In the two years that I have been using the system, I have >>>> never lost one of these >>>> drives. Thus my time to "do it over again" is zero (so far). I have >>> been >>>> working with raid >>>> extensively for about 5 years, and in those 5 years I have lost single >>>> drives but I have never lost >>>> two drives at the same time. >>>> >>>> I am sure that there are numbers out there that discuss the >>> probability of >>>> two drive failures. In >>>> fact IIRC from that paper by google, the probability of failure of any >>>> given single drive over 5 >>>> years was about 14%? The probability of two failures (my simple math) >>>> would be .14 * .14 = .0196 or >>>> ~ 2%. That is for two failures, NOT two SIMULTANEOUS failures. >>>> >>>> All of this matters if the cost is catastrophic. Facing a 2% chance >>> that >>>> I will have to re-rip 200 >>>> dvds in any given 5 year period, I am unwilling to commit the extra >>> money >>>> to preventing this >>>> possibility. >>>> >>>> This whole discussion does point out that an analysis of the actual >>>> numbers might cause one to come >>>> to a different conclusion. And who knows, you might decide "screw the >>>> costs", it is worth it to me. >>>> >>>> It is not worth it to me. >>>> >>>> Look at Unraid. >>>> >>>> http://lime-technology.com/ >>>> >>>> I am not trying to sell anyone on unRaid, I am simply saying consider >>> it >>>> for a specific class of >>>> redundancy needs. For this level of redundancy need, unRaid seems >>> like a >>>> good compromise. >>>> >>>> John W. Colby >>>> www.ColbyConsulting.com >>>> >>>> >>>> Michael Bahr wrote: >>>>> John, for your media collections you really should go only Raid 1. >>> Yeah >>>>> if you lose the HD you can re-do everything but who has the time? >>>>> Besides >>>>> 2TB HD's are ~<$150 or so. How much is your time worth? >>>>> >>>>> Mike... >>>>> >>>>>> I am about to build an UnRaid for my massive video / music >>> collection. >>>>>> I >>>>>> currently have no >>>>>> protection on that so if I lose a disk I lose all of that on one >>> disk. >>>>>> With Unraid I >>>>>> would have "raid 5 like" >>>>>> storage so that in the event of single drive failure I can still >>>>>> recover. >>>>>> If I do lose it I just >>>>>> re-rip. Not the end of the world but not something I want to do. >>>>>> >>>>>> John W. Colby >>>>>> www.ColbyConsulting.com >>>> -- >>>> AccessD mailing list >>>> AccessD at databaseadvisors.com >>>> http://databaseadvisors.com/mailman/listinfo/accessd >>>> Website: http://www.databaseadvisors.com >>>> >>> >> -- >> AccessD mailing list >> AccessD at databaseadvisors.com >> http://databaseadvisors.com/mailman/listinfo/accessd >> Website: http://www.databaseadvisors.com >> > >