Hi Henrique,
I have to chuckle at the famous last words - you don't have to worry about it (EBS).
For Pedro,
The EBS storage is configured automatically for you. But, it's useful to know how it's configured for HANA operations. Like any good configuration the database files, log files, and backup files are all located on separate mounted devices. When you configure HANA One for the labs, you will notice 13 EBS volumes are created for you, but the df command in Linux shows you something like this:
hanaserver:~ # df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda1 9.9G 3.0G 6.5G 32% /
devtmpfs 30G 152K 30G 1% /dev
tmpfs 30G 0 30G 0% /dev/shm
/dev/md0 119G 4.5G 108G 4% /hanalog
/dev/md1 197G 13G 175G 7% /hanadata
/dev/md2 197G 1.6G 186G 1% /backup
/dev/xvdj 30G 11G 18G 37% /usr/sap
/dev/xvdt 5.0G 1.3G 3.5G 28% /hci
This is because the /hanalog (four EBS volumes), /hanadata (four EBS volumes) and /backup (two volumes) devices use a RAID0 configuration to get more performance out of the devices. Basically, one EBS drive gives you 100 IOPS. If you tie four drives together, you can get up to 400 IOPS performance. This is a good thing for the /hanalog device as it used four. Having four drives for the /hanadata helps startup performance, but not much after data is loaded from disk into memory. Having the /backup drive with only two drives makes sense as this is not a common occurrence.
So, depending on your workload requirements, how HANA One configures it's drives can have a big impact. For purposes of the training - no problem. If you have to support very fast inserts, then having a really fast log drive needs to be a consideration as a transaction in memory must also be written to the log for durability.
The other thing you have to realize is what happens if a drive fails. With a traditional RAID0 configuration, if one drive goes down, the entire device is down - unlike other RAID configurations like RAID5. The good news is that AWS "mirrors" the EBS drives for you so you are getting what looks like RAID10 without the performance hit. The bad news is - there have been tragic instances where the AWS sysadmin as turned off the replication and a bad drive took down huge chunks of the AWS data center as a result of a cascading disk failure. I'm guessing since the last time this has happened, there is a big sign on the console that tells the system admin.
If you are using HANA One for a production environment, consider advice from people who have been there and done that like David - http://davidralbrecht.com/blog/tag/aws/ and Bruce@AWS - http://aws.amazon.com/articles/1074.
Regards,
Bill