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You get a lot more visibility and control with iSCSI, ATA over eth, infiniband, etc. The downside is you need to use and understand that visibility and control.
by donavanm 6y ago
You get a lot more visibility and control with iSCSI, ATA over eth, infiniband, etc. The downside is you need to use and understand that visibility and control. EBS is surfaced to you as a simple locally attached block dev. The network performance and challenges are not just managed for you, they’re largely opaque. As the user you can’t observe the (equivalent to) fiber channel topology, SCSI commands, discarded frames, etc. and that’s the power of EBS as well, users don’t have to deal with anything besides a locally attached virtual disk.
- p_l 6y agoSo much this. There's also the part where EBS SLA and durability might surprise you, like the great "internet disappeared" around 10 years ago.
- donavanm 6y agoThe last point is a good one around absolute vs subjective experience. If you’re looking at 1M disks 99.999% availability is great. But if your entire company runs on 10 instances your day will be utterly ruined when any one of those root volumes goes away. To that sad admin it feels like they’re sold 1/100,000 and got 1/10. And their impact is closer to “business critically failing” than “active automated remediation workflow incremented.”