The end of the road for tape?
Four reasons why tape has plenty of mileage left in the tank:
1 – It’s Cheap
The latest model – released in 2017 – is LTO8, which can store 12TB of raw data increasing to around 30TB with compression. The price of a leading brand works out at about £0.004 per GB, ignoring all ancillary costs such as tape libraries and drives, datacentre space, power, handling and storage. If the tapes are kept in a large-scale library in the datacentre, the ongoing cost including hosting, depreciation and maintenance can be as low as £0.0001 per GB per month. More commonly tapes are stored in a secure vault, where the ongoing monthly cost can be expected to be an order of magnitude cheaper (one thousandth of a penny). Compare that to the coldest tiers of public cloud storage which range from about £0.0008 to £0.0035 per GB per month depending on the tier and the provider. That the public cloud providers can even offer cold storage at these prices, along with the fact that data read times are much slower than more expensive tiers, has led to much speculation these options are tape-based.
In comparing cloud storage prices with ‘DIY’ tape, there are other factors to consider. Using the cloud at scale incurs other charges, notably for connectivity and data egress, but where cloud has very little management overhead once up and running, the same can’t be said for tape.
Looking ahead, the next generation of tape – LTO9 – will double the capacity of LTO8 although no release date has been set. Whether this has any effect on the relative economics of tape versus cloud remains to be seen. If LTO8’s release is anything to go by, LTO9 pricing – initially at least – will be more than double LTO8, negating the capacity advantage. In the meantime, public cloud providers may continue cutting prices as they have done several times in the past. At some point the cloud may overtake tape, but for large organisations that can achieve economies of scale and minimise the management overhead, tape still holds the advantage.
2 – It’s Compact, Robust and Portable
Tape is more portable than disk because transport is bad news for hard drives. In a datacentre lift and shift, if the drives are not removed from hardware and individually packed for the move, up to a quarter can fail either in transit or shortly after the device is brought back online. Even individually packed disks are not guaranteed to survive.
3 – Ransomware
Tape-based backups can provide an ‘air gap’ to recover from a ransomware attack that renders primary data unusable. Such incidents are unfortunately a common occurrence, with Travelex being the most recent high-profile case. Less public, but equally serious for the those involved, ransomware recently affected two other B2C companies which had to resort to tape backups.
Tape-based DR options are not quick to recover from and become increasingly problematic at scale, but they are a last resort that is enjoying something of a resurgence due to the number of high-profile cyber incidents. There are other methods, such as storage snapshots and encryption-blocking technologies, but tape is tried and tested.
4 – It’s Green
Once a tape is in long term storage, its ongoing carbon footprint is extremely low it consumes no power directly, merely a tiny fraction of the energy needs of the vault. Compare that to the constant electricity consumption of flash-based and disk-based systems, with the latter being the worst offender due to its moving parts. The power draw of the average hard drive – whilst at idle – is about the same as a low-energy domestic lightbulb.
Many firms cite eliminating tape as one of the main reasons to move backups to the cloud and at the smaller end of the spectrum this makes complete sense. Yet increases in tape capacity and its very low unit cost mean it’s still a great option to store data that doesn’t need to be accessed frequently. Along with the capability to recover from ransomware, tape isn’t disappearing any time soon.