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I don’t understand how this scales. If you have 1 PT to backup to tape, your first have to write it to disks on a backup server? So you have to buy 1PT worth o

I don’t understand how this scales. If you have 1 PT to backup to tape, your first have to write it to disks on a backup server? So you have to buy 1PT worth of backup disks first, is that correct?

kstrauser 6y ago
You wouldn't usually backup the whole thing first. That 1 PB is probably a bunch of smaller projects, so you'd create a tar of the first project, then flush it to tape. Tar up the second project, then flush it to tape. It's not so bad if you're writing 23 tarballs out to tape and pausing between each one. What you really want to avoid is where the tape drive is pausing many times during a single archive, perhaps because tar can't keep the drive fed while it's traversing a big directory of teensy files.
dragontamer 6y ago
You'd never buy a 1PB tape drive if you only had 1PB of data to backup. A 1 PB (1000TB) tape drive would probably cost $10,000+ to $100,000. The tapes themselves would be cheap (cheaper than hard drives or SSDs). So you'd buy many tapes, perhaps 50 of them, to be cost-effective. That's why a lot of comments around here are talking about tape libraries (entire boxes of tapes). You must plan to use more than 50 tapes (aka: 50PBs) before you reach any level of cost-effectiveness. --------- From there, we see that 1PB of data is simply "infrastructure", to help you lay out the data before it gets to the tape. There are 20TB hard drives today: a single machine with 50 x 20TB hard drives (and maybe some flash storage to accelerate the write to hard drives) is what we're looking at to feed the Tape Drive.
- tharkun__ 6y ago
  When I was a kid and we had to do a school internship, I went to my dad's company. Since we were just school kids, they didn't really give us anything to do. Except: Loading and unloading tapes and moving tape lists from the main tape library room to the backup safe. The backup safe was several hundred meters away in a different building (on the same lot). This was basically their WORM archival system. The tape library was a room full of tapes, wall to wall with shelves in the middle. Those were the oldest tapes. The in-use tapes were inside "Robbie", the circular tape robot. Not sure it it's this model exactly, but it sure looked like this: https://bjgreenberg.files.wordpress.com/2012/05/tape-library.jpg?w=800 https://bjgreenberg.files.wordpress.com/2012/05/tape-library... The tape robot would periodically spit out tapes on one end that we'd collect and then file away in the correct location on the shelves and vice versa, got a list of tapes to get from the shelves and insert into "Robbie". I don't remember typical tape sizes at the time, except that obviously it was much more capacity in a little tape than I had in my hard drives at home at the time :) Now imagine, Robbie filled to the brim with these 1PB tapes... Robbie and his extended tape library was in a room right adjacent to the actual data center floor, which had an IBM 390 mainframe and lots and lots of EMC^2s, AIXs, Suns and everything else you can think of being in a data center ca. 2000. You obviously had to get into and out of the data center through a single person entrance gate (a vertical tube that literally only one person could fit in, opening one side at a time only). First day I'd just walk through the data center and look at everything, reading labels and such. Found the server that all my personal emails were going through, as my ISP was hosting there! Heaven for a kid like me.
NovemberWhiskey 6y ago
Sure, why not? It's an incremental cost of the backup system. Look at the current generation stuff. An LTO-8 drive puts 30TB onto a tape, but that's assuming 2.5:1 compression, so the native capacity is only 12TB. Let's assume you're actually going to do the compression as you build the virtual tape. What's a 12TB hard disk cost these days? A lot less than the $4,000 that the tape drive costs. Heck, 12TB of SSD is going to be cheaper.
throw0101a 6y ago
60x18TB drives and a server to put them in would cost about US$ 45K: * https://www.45drives.com/products/storinator-xl60-configurations.php https://www.45drives.com/products/storinator-xl60-configurat... That gets you about 1PB raw.
deleted 6y ago
[deleted]

I don’t understand how this scales. If you have 1 PT to backup to tape, your first have to write it to disks on a backup server? So you have to buy 1PT worth of backup disks first, is that correct?

kstrauser 6y ago

You wouldn't usually backup the whole thing first. That 1 PB is probably a bunch of smaller projects, so you'd create a tar of the first project, then flush it to tape. Tar up the second project, then flush it to tape. It's not so bad if you're writing 23 tarballs out to tape and pausing between each one. What you really want to avoid is where the tape drive is pausing many times during a single archive, perhaps because tar can't keep the drive fed while it's traversing a big directory of teensy files.

dragontamer 6y ago

You'd never buy a 1PB tape drive if you only had 1PB of data to backup. A 1 PB (1000TB) tape drive would probably cost $10,000+ to $100,000. The tapes themselves would be cheap (cheaper than hard drives or SSDs). So you'd buy many tapes, perhaps 50 of them, to be cost-effective. That's why a lot of comments around here are talking about tape libraries (entire boxes of tapes). You must plan to use more than 50 tapes (aka: 50PBs) before you reach any level of cost-effectiveness. --------- From there, we see that 1PB of data is simply "infrastructure", to help you lay out the data before it gets to the tape. There are 20TB hard drives today: a single machine with 50 x 20TB hard drives (and maybe some flash storage to accelerate the write to hard drives) is what we're looking at to feed the Tape Drive.

tharkun__ 6y ago
When I was a kid and we had to do a school internship, I went to my dad's company. Since we were just school kids, they didn't really give us anything to do. Except: Loading and unloading tapes and moving tape lists from the main tape library room to the backup safe. The backup safe was several hundred meters away in a different building (on the same lot). This was basically their WORM archival system. The tape library was a room full of tapes, wall to wall with shelves in the middle. Those were the oldest tapes. The in-use tapes were inside "Robbie", the circular tape robot. Not sure it it's this model exactly, but it sure looked like this: https://bjgreenberg.files.wordpress.com/2012/05/tape-library.jpg?w=800 https://bjgreenberg.files.wordpress.com/2012/05/tape-library... The tape robot would periodically spit out tapes on one end that we'd collect and then file away in the correct location on the shelves and vice versa, got a list of tapes to get from the shelves and insert into "Robbie". I don't remember typical tape sizes at the time, except that obviously it was much more capacity in a little tape than I had in my hard drives at home at the time :) Now imagine, Robbie filled to the brim with these 1PB tapes... Robbie and his extended tape library was in a room right adjacent to the actual data center floor, which had an IBM 390 mainframe and lots and lots of EMC^2s, AIXs, Suns and everything else you can think of being in a data center ca. 2000. You obviously had to get into and out of the data center through a single person entrance gate (a vertical tube that literally only one person could fit in, opening one side at a time only). First day I'd just walk through the data center and look at everything, reading labels and such. Found the server that all my personal emails were going through, as my ISP was hosting there! Heaven for a kid like me.

NovemberWhiskey 6y ago

Sure, why not? It's an incremental cost of the backup system. Look at the current generation stuff. An LTO-8 drive puts 30TB onto a tape, but that's assuming 2.5:1 compression, so the native capacity is only 12TB. Let's assume you're actually going to do the compression as you build the virtual tape. What's a 12TB hard disk cost these days? A lot less than the $4,000 that the tape drive costs. Heck, 12TB of SSD is going to be cheaper.

throw0101a 6y ago

60x18TB drives and a server to put them in would cost about US$ 45K: * https://www.45drives.com/products/storinator-xl60-configurations.php https://www.45drives.com/products/storinator-xl60-configurat... That gets you about 1PB raw.

deleted 6y ago

[deleted]