Myth Busters
A while back my mentor Greg Schulz, founder of StorageIO, asked me what did I know about tape? I told him the topic has come up in my studies, but was looked down upon as a slow and old method for saving data. From this he asked if I would be interested in talking with someone who works with tape, and to shed some light on these myths I had. That is how I came in contact with Rich Gadomski. Rich works for Fujifilm as the Vice President of marketing for the commercial product division. During our talk, I learned my perspective of tape had been misguided. Below are some of the myths about tape, and the truth behind them.
Myth: Tape is slow
I hear this claim all the time with fellow students who jumped on the SSD bandwagon. The first question I ask them is why is tape slow? True if you are doing random reads tape will be slower than disk. However what if we want sequential reads, or sequential writes? Let us look at the specifications of Fujifilm’s most current magnetic tape LTO G6. Uncompressed LTO G6 has the ability to read/write sequential data at a rate of 160 MB/sec. If that data is compressed, the transfer rate can reach as high as 400 MB/sec. The issue is your network’s ability to feed data to your tape, not the tape itself.
Myth: Tape has low capacity
How many people who clam this really know the capacity of current tape? Before my interview with Rich I had no knowledge of the capacity of tape, but was surprised how comparable it was too Hard disk drives (HDD). I went to Seagate’s web site to learn current capacity of enterprise 2.5 and 3.5 HDD, compared it to Fujifilm’s LTO G6. The highest capacity of a 2.5 enterprise HDD capped out at 1TB, while a 3.5 enterprise HDD capped out at 6TB. LTO G6 currently has a capacity of 2.5 TB uncompressed and 6.25 compressed.
This is possible because of Barium Ferrite (BaFe). BaFe is a magnetic particle found in Fujifilm’s LTO G6 tapes. It is less dens then the metal particles found in older LTO tapes, and this allows more data to be stored on a single tape. Fujifilm predicts that this breakthrough will allow tape to reach a capacity of 35TB of uncompressed data in the near future.
Myth: Tape will be dead in 10 years
Let us look at what we have talked about so far, and see if this is true. We know tape is fast when it comes to sequential reads and writes. This makes tape perfect for recording, or recovering large sums of data.
Something Rich pointed out to me that I had never thought about is tape is cheap to maintain. You have to power SSD and HDD 24/7 costing money, and taking up resources. Yes this might not seem like much, but when you are powering hundreds of these devices, and powering the systems to keep them running (cooling, UPS systems, ect..) it starts to add up. Tape requires no power when it is not in use, and as long as it is stored within 60-95 degrees will maintain integrity.
Let us take a closer look at the integrity/reliability of tape, HDD, and SSD. It is not fair to compare the software that checks reliability since often times tape is used to save data after it has been on these other mediums for some time. This means the data has been checked multiple times if it is reliable before it is even written to tape. What we can look at is how all three compare when it comes to physical reliability.
When the tape in the cartridge snaps, is it possible to repair the tape, and recover most of the data? The answer is yes. The tape can be sent to a number of vendors to be repaired, and while there might be some data loss it is possible to recover most of the data. The same is true for HDD if it has been scratched, and SSD if a sector has gone bad. What does this mean? The answer is simply all three have roughly the same reliability physically.
We also know currently tape is competitive when it comes to capacity, and is only expected to grow in the future. The same is true for both HDD and SSD. While growth capacity for HDD has slowed down over the past couple of years new advances are currently being developed to ensure the continuant use of HDDs.
Closing thoughts
People need to stop seeing it as tape vs. disk, tape vs. flash, or flash vs. disk. My beliefs about tape, HDD, and SSD are the three should be working together to provide the best solution. Too often, we read about how one is going to replace the other, or how one is going to be gone in the next ten years. In reality, they have been coexisting for years, and will continue to do so for years to come. Next time you hear someone talking down about tape, educate them in their myths.
What’s Next
Over the next few weeks, a variety of topics are going to be covered. Optical, Buzzword Bingo, IPv6 are some of these topics.
I encourage fellow students of IT to leave suggestions on topics they would like to read about, and to engage in the conversation. After all, innovation cannot happen without conversation.
Feel free to follow me on twitter at Studentof_IT
Until next time
Cory Peden
StudentofIT 