LTO-4 backup speed

[Francis Flan]

From the HP website, it claims LTO-4 drives can backup up to 864GB/hr using 2:1 compression.

Can anyone confirm this rate ?

[Marino Meloni_1]

864GB/Hr is equal to 240MB/s this is the data rate of LTO4 using 2:1 compression.

for sure you should have enough bandwith from your data source to feed the drive at that seed.

[Mike Shilladay]

Hi Francis,

We have problems keeping an LTO-3 drive happy. i.e. not stopping and restarting. The drives works best at the beginning of our backup when it is being fed from a nice and quick VA7410 fibre channel disk array - this is when we get closest to what the specifications say.

Don't forget that if the files being backup are compressed already then no further compression will take place on the drive. There are exceptions to this but in general that is the case.

HP, just like anyone else will promote the best figures.

Mike.

[Wei Jung]

Hello Francis, most of the time the tape drive is not the bottleneck for your backup solution.
The tape drive is capable of doing 240MB/s but most hard drives won't be able to feed that amount of data.
It will depend if you are using concurrency or multiple streaming from different sources/hosts or different disks at the same time. This is achievable from the backup software, several ones support multiple streaming just to keep up with the speed of the tape drive.

Bear in mind that if you are using a controller or accessing disks not capable to keep up with the tape drive, this one would have to stop and restart every now and then to build up enough data to backup. This is called shoe shinning, and it might make your drive lifespan shorter.
So bottom line, if you are planning on use the LTO4 drive, make sure you got a good source of data stream you want to backup, if not you won't take advantage of all it's performance.