jwcolby
jwcolby at colbyconsulting.com
Wed Jul 21 21:48:24 CDT 2010
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 >> > >