Three things:
- ALL cost optimisation analyses – you’re optimising between cost, performance (speed), performance (reliability), and/or whatever else that matters to you (e.g. performance/Watt or any other metric).
This is true with any and ALL cost optimisation studies.
That would like you saying that you can choose to buy/drive a vehicle with a powersplit hybrid architecture vs. a Jeep.
You can choose to drive like a maniac and drive 140 km/h (87 mph) everywhere, but your fuel economy is going to suck as a result of it (where you’ve optimised it for speed) or you can drive the hybrid at 110 km/h (69 mph) and just relax and cruise, because you know that you are going slower, but more efficiently and you pay for the difference in the cost to fill up your tank and the frequency of needing to do so.
Similarly, along the lines of the cost optimisation problem – you CAN replace your entire mass storage system with SSDs, but again, you’re trading performance (faster speed) with reliability and cost.
The difference between the FH and HH tape drives is no different than that.
You pay more for the FH drive, but it runs slightly faster than the HH drive.
But like a long road trip, if it’s going to take you 12 hours for you to get to your destination, does it REALLY matter if you shave 20 minutes off said 12 hour drive?
The theoretical speeds of the FH vs. HH drive, especially for LTO-9 is supposed to be a peak of upto 400 MB/s.
I am not sure how much physical/practical experience you have with LTO-8 (and newer tape drives), but I can tell you, based on my actual experience with my actual LTO-8 HH tape drive, that the theoretical peak speeds is precisely that – a theoretical peak speed.
In practice, I am ususally SIGNIFICANTLY slower than that.
If I am writing the pictures my wife takes of the kids – each picture is only a few MB. Even if we were to assume that a picture is 20 MB, if you’re writing a picture per second, (again, I am using rsync to write it, not mbuffer), you’re still, at max, writing at 20 MB/s, in actual, practical reality.
This is why, in all of the speed calculations, I specifically caveat the calculation with two assumptions:
-
The full capacity (vs. the 80% of the tape’s native capacity is the more general, “rule-of-thumb” recommendation (don’t write it completely)) and
-
That you are able to write that native capacity, in a day, where in many cases, you can’t for a variety of reasons (source storage system may be fragmented (as it is with ZFS), so your HDDs have to hunt around a little bit for the data.
(e.g. my main storage pool right now, as reported by zpool list shows a size of 231 TiB, at 78% capacity, and 40% free space fragmentation)
Therefore; given that, there is a decent chance that I won’t be able to sustain even the 300 MB/s that the LTO-8 HH drives are supposed to be capable of.
I’ve RARELY ever seen it hit that. MOST of the time, it’s sitting closer between the 70-80 MB/s mark.
Therefore; who cares if the FH drives can do the stuff faster.
The actual, practical matter of reading and writing data from/to the tape can’t go any faster anyways, for the rest of the reasons, in the entire chain of (potential) bottlenecks.
Yes, the other things MAY benefit, but you’re not necessarily guaranteed to be able to reap the rewards of the differences between FH and HH drives, especially in a single, manually loaded drive configuration.
I tend to fill my drives up to 10.5 TiB. (87.5% capacity, which I know, is higher than the “rule-of-thumb” recommendation)
If I am able to write at an average of about 80 MiB/s, then it would take 137625.6 seconds for me to write to that capacity level or approximately 1.6 days.
Therefore; spending 47% more ($7198/$4894 per backupworks.com pricing) for something that may yield upto 33% benefit (no guarantee that you’ll actually reap the full 33% reward/benefit), works out to be a 1.1% price increase per 1% increase in potential performance (speed) increase.
Again, this cost optimisation isn’t unique to FH vs. HH drives.
You can replace your entire bulk storage with SSDs.
But I am going to bet that you probably didn’t/haven’t.
This cost optimisation is no different than that.
^Agreed.
I tried googling this and couldn’t come up with any sources that state nor stipulate this.
So, if you have a reference that you are able to pass along so that I can read it, that would be greatly appreciated.
(I would be surprised if this was the case, but until I read the reference, I can’t speak to it, one way or another. But a quick google for this came up completely empty handed.)
[citation needed]
[also citation needed]
I’ll summarise this discussion this way – out of the people who has responded, it would be interesting to know how many have a LTO-8 tape drive system that they have, at their house.
(Again, this is the use case that I am assuming as the OP doesn’t say what use case he is looking to get one for.)
If the people who have one, are speaking from their actual experiences of using one, then to me, at least, that would carry more “weight” than people who might be speaking about this topic mostly (or purely) from the theoretical perspective.
There are a LOT of things that people can talk about, based on theory.
And I can personally attest that when it comes to the actual, practical deployment – theory can often times, have little bearing nor relationship to reality.
Remember that the calculations for the peak transfer rates of the FH vs. HH drives are under “ideal”, lab conditions (so that their tests can be conducted in a reliable and repeatable manner). But out in the actual, real world deployments, it’s not a lab setting, and therefore; all of the things that were used to create the “perfect” lab condition, goes out the window when it’s deployed in the basement of my home.
There are no shortage of ways/things that can end up taking you far, far, far away from the ideal/theoretical maximum transfer rates.
And it really doesn’t take much, with LTO, to end up slowing it down.
(Like ideally, I should be backing up my data to another server and then have that server be the source of the data that’s going up on tape. But being “cost-efficiency minded”, I don’t have a second server, with a grand total of 231 TiB + 43.7 TiB + 12 TiB = 286.7 TiB of storage to be able to ingest/backup my data onto before sending said data over to tape. Hard drives alone, (12 TB drives at $108.88 off of eBay) would run me $2613.12. And that’s BEFORE I buy another 36-bay 4U server, where one of the servers that I am watching on eBay, is going for $1396.04. That will bring the combined total for the new server up to $4009.16.)
And again, as I mentioned, that’s just if I want to store the data that I have right now.
That doesn’t include the data that have already offloaded onto tape.
You can buy a 12 TB LTO-8 tape for $58.75 USD
You still can’t buy a 12 TB HDD for that price.
If you’re only planning on backing up 12 TB of data, then it would be silly and senseless to get a LTO-8/9 tape drive system.
But like I said, when I did the original optimisation calculations, my “breakeven point” was about 150 TB.
That’s where it made more sense to go tape than more HDDs (hot or cold storage).
Like I said, you can build a very simple Excel spreadsheet to run the cost optimisation for yourself to see what works best for you, as a function of how much data you want to or need to backup and you can decide from there, which option works better for you.
I’m not here to dictate nor sell you on going with one option or the other.
I’m just conveying my experiences and how I ran the cost optimisation calculations for myself, and then using that analysis, made the decision for what works best for me.
And what works best for me, may not work for you, and that’s 100% ok as well.
But I am also of the opinion that it is much better to speak from experience, rather than theory, because there are a lot of things that take me away from the theoretical peak/sustained data transfer rates.
If you have more questions, please feel free to ask.
I hope this helps.
Thanks.