Carl Cook put forth on 12/26/2010 6:06 PM: > On Sun 26 December 2010 12:33:30 Neil Brown wrote: >> But the important thing is that you have your data back, preparing you for a >> Happy New Year! >> NeilBrown > > Indeed. Thank you Neil, you saved me (along with my not touching anything). > > > On Sun 26 December 2010 13:14:32 you wrote: >> Excellent save!!! The OP might want to continue the "Giving Season" by >> giving himself a brand new system backup. > > Actually I have much too much data to back anything up <snip> Every time I read/hear this I cringe. If that is the case your data is worthless to begin with so just delete it all right now. You are literally saying the same thing with your statement. The difference is that I _KNOW_ you drives will fail, or you'll lose an array due to corruption, etc. Your HTPC storage system will fail. It's not an _IF_ but a _WHEN_ issue. The question then becomes, what is the best backup/restore strategy to fit HTPC needs. Build another system with similar technology and you have the same failure modes and risks as the first. Spinning Rust Disks (SRDs) are not a suitable long term backup/restore solution. What happens when your disk-to-disk backup server solution drops an MD array for no reason such as just happened, _during_ a restore operation? Or you suffer a disk failure on the backup server during a restore operation (which is very common today)? Will your backup server contain a 4 x 2 TB disk RAID 10 set? I'd suggest tape as the better solution to D2D in the HTPC case, primarily based on cost and availability of library and media, and the fact the disaster recover procedure is much easier and much more straightforward: 8 drive LTO-2 autoloader http://www.msrcglobal.com/p-216-af203a.aspx?gclid=CI789Mm_i6YCFQTrKgodIg0pnA&; http://h18000.www1.hp.com/products/quickspecs/11841_div/11841_div.HTML Ultrium 448 drive 3.2 TB compressed max per library U160 LVD/SE SCSI interface 172 GB/hour capacity - "desktop" model $650 USD http://www.newegg.com/Product/Product.aspx?Item=N82E16816118057 $90 USD http://www.newegg.com/Product/Product.aspx?Item=N82E16840999118 8 x $22 = $176 USD Total = $916 + shipping Using the correct backup strategy this should easily meet your needs. The 8 tapes in the library will handle 75% of your RAW level 10 mdraid device capacity. Once a filesystem is laid down, and you take overhead concerns into account, you won't be putting more than 3.2 TB of data on it anyway (or, at least, you SHOULDN'T be doing so). The total cost should be similar to a disk based backup server but the reliability and ease of restore should be better. There's no beating a tape library as a long term backup solution, especially for data that doesn't change often, such as HTPC files. 10 tapes for 4 TB of space is $220. How much does a 4 TB SATA drive cost? Or 2 x 2TB drives. Quite a bit more. You can store spare tapes more easily than spare drives, and the tapes take almost zero configuration when adding capacity to the backup system. Adding drives, especially if you don't buy a large chassis with hot swap bays up front, is much more a PITA. Keep in mind that using tape allows essentially unlimited backup expansion, whereas you are severely limited with a backup server for your HTPC unless you buy a large box upfront, which nobody doing HTPC wants. Each time you add larger/more disks to the HTPC, you have to do the same for the backup server. With tape, you simply swap tape inventory and create a modified or new backup schedule. Many people outside the corporate/government data center completely ignore tape today as a backup solution. Many times at their peril. -- Stan -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
