Hello, world. Penned down some keywords after passing my recent AWS SOA exam, and then expanded on ’em below. Perhaps you’ll find ’em useful then.
EBS RAID 0 (striped) vs. 1 (mirrored); i.e., the lower the number, the higher the risk, see https://www.diffen.com/difference/RAID_0_vs_RAID_1.
Just like EC2 instances, EBS volumes reside in a specific AZ of a Region; i.e., they can only be attached to a running instances within the same AZ.
I recently became fully AWS certified (at the Associate Level), most recently passing the the SysOps Administrator - Associate exam at my third attempt.
In late 2016, I failed with a score of 61% (or 67%). It was my first failure – I deleted the “unsuccessful” notification email in a fit of rage; In early 2018, I failed with a score of 71%; In April 2018, I passed with a score of 80%.
After an extended hiatus away from AWS certification, finally I’m certified at the Associate level, 3 times over!
To date I’ve taken and passed:
Certified Developer - Associate Certified Solutions Architect - Associate Certified SysOps Administrator - Associate AWS has a nice road map, so I just re-purposed the following image off their site:
I’m told that the Professional level exams are much harder, but that’s a post for another day…
Yesterday, we encountered a disk issue on one of our CentOS servers. Some of the disks had either failed, or were predicting failure, so our vendor swooped in, changed some of the disks, as well as the RAID controller. Unfortunately, this worked for only a short time, before we started seeing “input/output error” verbiage in the console. The concern was data loss, so we tried to shutdown, reboot: same “input/output error”.