4 ms·

But why use tape storage in this day and age?

by yapyap 2y ago

dogma1138 2y ago
Cheap and very very reliable archival storage (essentially no failure modes other than the magnetic media itself), weight and volume wise pretty much still the best density you can get 18TB (up to 45 with compression) in a small 200g package is hard to beat when you need to move peta bytes around. Also tape is much cheaper to produce than platters especially at large volumes.
- nshkrdotcom 2y ago
  How does such tape compare to 2" and 1/2" analogue reel to reel tape, in terms of production costs? A new reel of Ampex 2" tape is $375.00 currently: https://vintageking.com/atr-magnetics-studio-master-tape-blue-2 https://vintageking.com/atr-magnetics-studio-master-tape-blu...
  - dogma1138 2y ago
    I don’t know but over the counter direct purchase single unit LTO 9 tapes are about £70-80 each in the UK for 18TB, in large volumes they are much cheaper, I’ve seen quotes in the £30 per tape and that wasn’t at a cloud provider or even massive enterprise scale or anywhere close to that.
  - deleted 2y ago
    [deleted]
rwmj 2y ago
Tape has a tremendous density advantage over disks. Think about how much area a tape occupies if you were to completely unroll it, and compare that to a disk platter. The flip side is access times are extremely long compared to disks, but for the usual application of backup and recovery that doesn't matter much. In this case they're pairing the tape with faster non-volatile storage so writes at least will be very quick (reads not so much, 2 minute access time!)
- dogma1138 2y ago
  The 2min number is likely an average over a large volume of drives. An LTO 9 tape has over a kilometer(!) of tape in it. You can spool the tape only so fast without risking damage to either the tape itself or the cartridge so if your file is at the end of the tape you’ll be waiting for a while.
  - Dylan16807 2y ago
    It's a single tape. Even without any kind of fast forward, the write speed of LTO-9 is 6 meters per second. It takes three minutes to go completely end to end.
hks0 2y ago
I think makes perfect sense for archiving. I keep hearing tapes last 30 years, while in the same room temperature SSDs last a few years. Just wish I could find a solid source for it!
- dogma1138 2y ago
  You can buy LTO tapes from Amazon and office suppliers easily. The drives and the software are the problem. Drives are very expensive and there isn’t much non enterprise software to manage tape backups. Enterprise software is expensive and you won’t likely be even able to buy it and since cloud storage and NAS became commoditized all the backup software that targeted small businesses pretty much either died off or went cloud backup only.
- wtallis 2y ago
  A worn-out SSD is supposed to be able to preserve its data for one year for consumer SSDs or three months for enterprise SSDs (not at the same temperature). That's the industry-standard threshold of data retention used to determine how "worn out" is considered end-of-life. A SSD that hasn't burned through its entire write endurance will have considerably longer data retention.
  - Sakos 2y ago
    We're not talking about write endurance though? From what I've read, unpowered SSDs only hold the data for a year or two, regardless of the age of the drive.
    - wtallis 2y ago
      > From what I've read, unpowered SSDs only hold the data for a year or two, regardless of the age of the drive. You've probably been reading bad sources. There is a very real relationship between the number of P/E cycles that a piece of flash memory has been through and the unpowered data retention it can provide. Lots of publications and even more random forum posts repeat statements about SSD data retention without including the caveat that the numbers apply specifically to worn-out drives. Brand new flash memory can easily have unpowered data retention in excess of a decade. If you're reading a source that claims SSD unpowered data retention is only a year, and that source does not qualify that with a statement about the prior condition of the drive, you should assume that you're reading another misinterpretation of the JEDEC standards.
pascoej 2y ago
Backups or satellite imagery is my guess.
SoftTalker 2y ago
"Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway." For big data transfers, this still holds true.
mtkd 2y ago
There are no downsides to keeping off-cloud physical backup sets of most critical data in a firesafe or two (and still needed for SOC 2 compliance I understand) > Aug 23: CloudNordic said: “The attackers succeeded in encrypting all servers’ disks, as well as on the primary and secondary backup system, whereby all machines crashed and we lost access to all data.”
082349872349872 2y ago
In the 1980s or 90s, Jim Gray predicted that in the far future memory hierarchy would be reduced to main memory + tape. Not sure that prediction holds up (although streaming dbs in the cloud seem awfully "tape-like" to me?), but I did attempt to quickly redo his "5 minute rule" calculations: https://news.ycombinator.com/item?id=42125052 https://news.ycombinator.com/item?id=42125052 If I did the math right, there's no point to swap or paging anymore, as the break-even point I got was evict after 1 week* (instead of 5 min) for random access patterns, and evict after 5 hours for sequential access patterns. These days maybe those breakeven calculations would be more useful for deciding how long to keep something in a register and when it'd be better to recalculate or spill to main memory? * of course, if you keep everything in main memory and forget nothing, we're close to what in 1998 was one of McCarthy's pipe dreams: Elephant2000 http://www-formal.stanford.edu/jmc/elephant/elephant.html http://www-formal.stanford.edu/jmc/elephant/elephant.html ; I guess if I were to attempt something like Elephant2038, it'd wind up looking like a bunch of past-oriented LTL formulae? (the "speech acts" were probably Winograd's influence?)
- gradschoolfail 2y ago
  Not to needlessly alleviate your suffering, but what is LTL? Of course, these Nobel Bauble driven days, “quantum memories” sound like little more than search engine bawdlerised AdWords..
  - 082349872349872 2y ago
    Linear Temporal Logic: https://www.cs.colostate.edu/~france/CS614/Slides/Ch5-Summary.pdf https://www.cs.colostate.edu/~france/CS614/Slides/Ch5-Summar... (for Xφ, I prefer to define it as relative to a given frame: φ holds the next time any of the frame variables change, which allows both continuous<->discrete translation and for Lamport's stuttering [to allow abstraction!]) Next up: GC via creation and annihilation operators? (in my algebraic view of informatics, one is often either structuring by cleaving two parts to make a whole, or destructuring by cleaving a whole into two parts) EDIT: and by past-oriented I mean using "was ever" for "eventually" and in the past for "globally", as well as "since" for "until". rotate t by i^2. Eg dirty := F{edit} U ({save} ∨ {load}) says the local buffer differs from the cloud if there was ever an edit since a save or load. EDIT 2: ...and I'm pretty sure I can autogenerate code that turns these kinds of def'ns into an imperative event-driven state machine; one can of course come up in theory with formulae that require an arbitrarily complex implementation, but I think in practice most def'ns (especially if we provide backpressure by signalling the complexity of the resulting imp) would be satisfied with simple ones.

But why use tape storage in this day and age?

by yapyap 2y ago

But why use tape storage in this day and age?

Cheap and very very reliable archival storage (essentially no failure modes other than the magnetic media itself), weight and volume wise pretty much still the best density you can get 18TB (up to 45 with compression) in a small 200g package is hard to beat when you need to move peta bytes around. Also tape is much cheaper to produce than platters especially at large volumes.

nshkrdotcom 2y ago
How does such tape compare to 2" and 1/2" analogue reel to reel tape, in terms of production costs? A new reel of Ampex 2" tape is $375.00 currently: https://vintageking.com/atr-magnetics-studio-master-tape-blue-2 https://vintageking.com/atr-magnetics-studio-master-tape-blu...
- dogma1138 2y ago
  I don’t know but over the counter direct purchase single unit LTO 9 tapes are about £70-80 each in the UK for 18TB, in large volumes they are much cheaper, I’ve seen quotes in the £30 per tape and that wasn’t at a cloud provider or even massive enterprise scale or anywhere close to that.
- deleted 2y ago
  [deleted]

rwmj 2y ago

Tape has a tremendous density advantage over disks. Think about how much area a tape occupies if you were to completely unroll it, and compare that to a disk platter. The flip side is access times are extremely long compared to disks, but for the usual application of backup and recovery that doesn't matter much. In this case they're pairing the tape with faster non-volatile storage so writes at least will be very quick (reads not so much, 2 minute access time!)

dogma1138 2y ago
The 2min number is likely an average over a large volume of drives. An LTO 9 tape has over a kilometer(!) of tape in it. You can spool the tape only so fast without risking damage to either the tape itself or the cartridge so if your file is at the end of the tape you’ll be waiting for a while.
- Dylan16807 2y ago
  It's a single tape. Even without any kind of fast forward, the write speed of LTO-9 is 6 meters per second. It takes three minutes to go completely end to end.

hks0 2y ago

I think makes perfect sense for archiving. I keep hearing tapes last 30 years, while in the same room temperature SSDs last a few years. Just wish I could find a solid source for it!

dogma1138 2y ago
You can buy LTO tapes from Amazon and office suppliers easily. The drives and the software are the problem. Drives are very expensive and there isn’t much non enterprise software to manage tape backups. Enterprise software is expensive and you won’t likely be even able to buy it and since cloud storage and NAS became commoditized all the backup software that targeted small businesses pretty much either died off or went cloud backup only.
wtallis 2y ago
A worn-out SSD is supposed to be able to preserve its data for one year for consumer SSDs or three months for enterprise SSDs (not at the same temperature). That's the industry-standard threshold of data retention used to determine how "worn out" is considered end-of-life. A SSD that hasn't burned through its entire write endurance will have considerably longer data retention.
- Sakos 2y ago
  We're not talking about write endurance though? From what I've read, unpowered SSDs only hold the data for a year or two, regardless of the age of the drive.
  - wtallis 2y ago
    > From what I've read, unpowered SSDs only hold the data for a year or two, regardless of the age of the drive. You've probably been reading bad sources. There is a very real relationship between the number of P/E cycles that a piece of flash memory has been through and the unpowered data retention it can provide. Lots of publications and even more random forum posts repeat statements about SSD data retention without including the caveat that the numbers apply specifically to worn-out drives. Brand new flash memory can easily have unpowered data retention in excess of a decade. If you're reading a source that claims SSD unpowered data retention is only a year, and that source does not qualify that with a statement about the prior condition of the drive, you should assume that you're reading another misinterpretation of the JEDEC standards.

pascoej 2y ago

Backups or satellite imagery is my guess.

SoftTalker 2y ago

"Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway." For big data transfers, this still holds true.

mtkd 2y ago

There are no downsides to keeping off-cloud physical backup sets of most critical data in a firesafe or two (and still needed for SOC 2 compliance I understand) > Aug 23: CloudNordic said: “The attackers succeeded in encrypting all servers’ disks, as well as on the primary and secondary backup system, whereby all machines crashed and we lost access to all data.”

082349872349872 2y ago

In the 1980s or 90s, Jim Gray predicted that in the far future memory hierarchy would be reduced to main memory + tape. Not sure that prediction holds up (although streaming dbs in the cloud seem awfully "tape-like" to me?), but I did attempt to quickly redo his "5 minute rule" calculations: https://news.ycombinator.com/item?id=42125052 https://news.ycombinator.com/item?id=42125052 If I did the math right, there's no point to swap or paging anymore, as the break-even point I got was evict after 1 week* (instead of 5 min) for random access patterns, and evict after 5 hours for sequential access patterns. These days maybe those breakeven calculations would be more useful for deciding how long to keep something in a register and when it'd be better to recalculate or spill to main memory? * of course, if you keep everything in main memory and forget nothing, we're close to what in 1998 was one of McCarthy's pipe dreams: Elephant2000 http://www-formal.stanford.edu/jmc/elephant/elephant.html http://www-formal.stanford.edu/jmc/elephant/elephant.html ; I guess if I were to attempt something like Elephant2038, it'd wind up looking like a bunch of past-oriented LTL formulae? (the "speech acts" were probably Winograd's influence?)

gradschoolfail 2y ago
Not to needlessly alleviate your suffering, but what is LTL? Of course, these Nobel Bauble driven days, “quantum memories” sound like little more than search engine bawdlerised AdWords..
- 082349872349872 2y ago
  Linear Temporal Logic: https://www.cs.colostate.edu/~france/CS614/Slides/Ch5-Summary.pdf https://www.cs.colostate.edu/~france/CS614/Slides/Ch5-Summar... (for Xφ, I prefer to define it as relative to a given frame: φ holds the next time any of the frame variables change, which allows both continuous<->discrete translation and for Lamport's stuttering [to allow abstraction!]) Next up: GC via creation and annihilation operators? (in my algebraic view of informatics, one is often either structuring by cleaving two parts to make a whole, or destructuring by cleaving a whole into two parts) EDIT: and by past-oriented I mean using "was ever" for "eventually" and in the past for "globally", as well as "since" for "until". rotate t by i^2. Eg dirty := F{edit} U ({save} ∨ {load}) says the local buffer differs from the cloud if there was ever an edit since a save or load. EDIT 2: ...and I'm pretty sure I can autogenerate code that turns these kinds of def'ns into an imperative event-driven state machine; one can of course come up in theory with formulae that require an arbitrarily complex implementation, but I think in practice most def'ns (especially if we provide backpressure by signalling the complexity of the resulting imp) would be satisfied with simple ones.