LTO-6 drives can put 2.5TB uncompressed onto one tape and can be picked up at a decent price since they're 2 generations behind the latest. LTO-7 puts 6TB uncompressed onto a tape but used/surplus drives are still going for over $1K.LTO-8 does 12TB uncompressed but you'll need to drop over $3K for a drive. I wouldn't go for any older than an LTO-5 with 1.5TB capacity. 1 through 4 were 100GB, 200GB, 400GB, 800GB uncompressed capacities.
LTO = Linear Tape Open, or as Hewlett Packard, IBM, and Quantum call it, Ultrium. The tapes are affordably priced for their capacity. PCI Express SAS controllers are also available at decent prices. The drive manufacturers have decided to exclusively market to the big business / datacenter segment. If they did a properly targeted promotional campaign I could see a USB-C / eSATA connected external LTO drive at a price well below $1K taking a big chunk of the SOHO backup market. I have three 1TB drives in my desktop plus two 4TB external drives, a 500GB external and some smaller externals. I'd love to be able to put all my stuff onto ONE low cost tape, without compression, and at such low cost I could make a second and even third backup copy. LTO has for years been the only backup media that's not another hard drive able to backup the largest contemporary hard drive size onto a single piece of media, without compression. Tape technology is know for its long term stability + low media cost. Hard drives can also be stable long term storage but at a much higher cost. With the rapidly changing technology of SSDs, there is no comparable experience with long term data stability. A term you may have heard in relation to SSDs is 2D NAND, 3D NAND, or even 4D NAND. Essentially that's how many 'layers' there are per memory cell. The higher the D number, the more data can be packed into the same physical chip die. Unfortunately the higher the D number the *slower* the speeds. 4D NAND SSD's can be as slow as a hard drive. Another important thing is how large of a cache an SSD has, if any. Higher priced ones tend to have a large RAM cache to have a very high speed transfer, then move the data to the NAND chips. If you shove a file at the SSD that's larger than its cache, the write speed will drop. One more issue with all solid state storage is they write slower when 50% or more full. They all have built in 'wear leveling' systems that randomize where data is written. If you copied and deleted and re-copied one file to an SSD a huge number of times it's likely it would never occupy the exact same set of cells twice. But once data is written it stays in the same cells until it's changed or deleted. That reduces the pool of available cells for the wear leveling, which increases the wear on the empty portion. Never ever defragment an SSD. It's completely un-necessary, the cells all have the same access speed and there's no seek time. Defragging only increases the wear on the chips. But despite the big improvements in durability I wouldn't put a swap file or scratch partition on an SSD. In 2013 techreport com started a test to destruction on six new SSDs in the 240 to 256 gig range. Some survived into 2015, wearing out after nearly 2.5 petabytes of randomized data writes and deletions. https://techreport.com/review/27909/the-ssd-endurance-experiment-theyre-all-dead On Monday, January 14, 2019, 7:53:29 PM MST, Jon Elson <el...@pico-systems.com> wrote: On 01/14/2019 12:16 PM, Chris Albertson wrote: > > Oe of the worst problem is #1. A files that you don't read very often > gets corrupted. and then is propagated all over you backup media. > This takes some thought to prevent. The ONLY way is versioned backup > -- NEVER overwrite old data with new. I've been trying to stay ahead of the data explosion by constantly improving backup systems. Right now, I back up to blu-ray discs every couple weeks (Oh, I wish ... OK, every couple months) that are stored in a fire safe. The advantage here is that they are not re-writeable media, so there is saved history if I should need it. And, I back up every couple days to a large spinning hard drive. My live discs are SSDs. I don't know how long the blu-rays are going to be sufficient, they are already too small to hold everything, so I have to do it in sections. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
