1 00:00:00,510 --> 00:00:01,410 ‫So now let's talk about 2 00:00:01,410 --> 00:00:05,160 ‫the Multi-Attach feature of the EBS volumes. 3 00:00:05,160 --> 00:00:06,630 ‫So as the name indicates, 4 00:00:06,630 --> 00:00:08,730 ‫the Multi-Attach feature allows you to attach 5 00:00:08,730 --> 00:00:13,170 ‫the same EBS volume to multiple EC2 instances 6 00:00:13,170 --> 00:00:15,660 ‫in the same availability zone. 7 00:00:15,660 --> 00:00:16,493 ‫So what does that mean? 8 00:00:16,493 --> 00:00:17,340 ‫That means that, well, 9 00:00:17,340 --> 00:00:19,590 ‫we have multiple EC2 instances, 10 00:00:19,590 --> 00:00:21,360 ‫and we have an io2 volume 11 00:00:21,360 --> 00:00:23,520 ‫with the Multi-Attach feature enabled. 12 00:00:23,520 --> 00:00:25,440 ‫Then this volume can be attached 13 00:00:25,440 --> 00:00:28,620 ‫to multiple EC2 instances at a time, 14 00:00:28,620 --> 00:00:31,740 ‫which is something that is only available 15 00:00:31,740 --> 00:00:36,740 ‫for the io1 and the io2 family of EBS volumes. 16 00:00:36,960 --> 00:00:38,850 ‫Now, each instance will have 17 00:00:38,850 --> 00:00:41,250 ‫full read and write permissions 18 00:00:41,250 --> 00:00:43,680 ‫to the high-performance volume. 19 00:00:43,680 --> 00:00:44,880 ‫And so that means that they can all 20 00:00:44,880 --> 00:00:46,740 ‫write and read at the same time. 21 00:00:46,740 --> 00:00:48,390 ‫So the use case for this is 22 00:00:48,390 --> 00:00:51,120 ‫you have higher application availability 23 00:00:51,120 --> 00:00:53,340 ‫in case of a clustered Linux application, 24 00:00:53,340 --> 00:00:55,200 ‫for example, using Teradata, 25 00:00:55,200 --> 00:00:57,390 ‫or if your application must manage 26 00:00:57,390 --> 00:00:59,370 ‫concurrent rights operation. 27 00:00:59,370 --> 00:01:00,660 ‫So just so you know, 28 00:01:00,660 --> 00:01:03,390 ‫this Multi-Attach feature is only available 29 00:01:03,390 --> 00:01:07,200 ‫from within a specified availability zone, of course. 30 00:01:07,200 --> 00:01:09,900 ‫It doesn't allow you to attach an EBS volume 31 00:01:09,900 --> 00:01:12,420 ‫from one AZ to another AZ. 32 00:01:12,420 --> 00:01:14,850 ‫Another limitation of Multi-Attach is 33 00:01:14,850 --> 00:01:19,080 ‫that it is up to 16 EC2 instances at a time 34 00:01:19,080 --> 00:01:21,630 ‫that can be attaching the same volume. 35 00:01:21,630 --> 00:01:23,820 ‫And this is something you have to know for the exam, 36 00:01:23,820 --> 00:01:26,910 ‫so be careful to that 16 number. 37 00:01:26,910 --> 00:01:28,800 ‫Finally, for it to work, 38 00:01:28,800 --> 00:01:30,030 ‫you must use a file system 39 00:01:30,030 --> 00:01:31,920 ‫that is going to be cluster-aware. 40 00:01:31,920 --> 00:01:35,700 ‫So it's a different file system than XFS or EX4. 41 00:01:35,700 --> 00:01:37,740 ‫And this is just a little bit more details, 42 00:01:37,740 --> 00:01:41,040 ‫but in case you wanted to use this feature, now you know. 43 00:01:41,040 --> 00:01:43,500 ‫Okay, that's it for this lecture, I hope you liked it. 44 00:01:43,500 --> 00:01:45,650 ‫And then we'll see you in the next lecture.