What type of compression do you get on a LTO-4 Drive?
I want to know some personal stats of companies using a Quantum or HP LTO-4 Drives for their tape backup? I will be using it with backup exec. and an estimated time of backing up 300GB of data not based on specs but by experience.
The tests we’ve done on LTO-4’s have them running consistently at 107 to 113MB/sec (up to 6.6GB/min). Of course, this assumes that your drive array can handle that kind of consistent throughput. I would say a minimum of a 5 drive RAID5 array (U160 or U320). A single U320 SCSI drive will usually max out at 65MB/sec, which will drop when the seek heads have to jump to different locations on the platters.
You definitely do not want to attempt to backup directly to tape from the network. Even Gigabit Ethernet.
As for compression, I really couldn’t tell you. It is almost entirely based on your data. If a bulk of your data is text, documents and database files, compression will be good. If you have a large amount of images, videos or other such data (already compressed), you won’t see much compression at all. That would based on the total size of the types of files, rather than the number of files.
January 21, 2009 at 12:04 PM