Re: [CentOS-virt] CentOS Images on AWS with partitions on /dev/xvda1 are awkwared to resize
I think the command-line is far more flexable then the GUI interface. I use ec2-api-tools, but the python boto stuff works virtually the same. On Thu, 30 Apr 2015, Nico Kadel-Garcia wrote: On Wed, Apr 29, 2015 at 11:33 PM, Kelly Prescott wrote: to follow-up, I will give an example. Here is the listing for the official centos AMI: IMAGE ami-96a818feaws-marketplace/CentOS 7 x86_64 (2014_09_29) EBS HVM-b7ee8a69-ee97-4a49-9e68-afaee216db2e-ami-d2a117ba.2 aws-marketplace available public [marketplace: aw0evgkw8e5c1q413zgy5pjce] x86_64 machineebs hvm xen BLOCKDEVICEMAPPING EBS /dev/sda1 snap-591037fd 8 false standardNot Encrypted as you can see the block device mapping is by default set to BLOCKDEVICEMAPPING EBS /dev/sda1 snap-591037fd 8 false standardNot Encrypted it is a standard volume, not encrypted, and 8 GB my modification consists in adding this to my run command for my ami launch: -b /dev/sda1=snap-591037fd:20:false:gp2 I set the drive the same, the snapshot the same, and I give it 20GB instead of 8, I also use the gp2 type instead of the standard as well as telling it not to delete the volume when the instance terminates. Hope this helps. kp Perhaps so, and I appreciate the pointer. I can try to work with that to integrate command line based deployment and get this option. So you're working from the command line tools in the EPEL 'cloud-init' package, not the AWS GUI? Because when I tried expanding the size of the base disk image in the GUI, I wound up with an an 8 Gig default /dev/xvda1 on a 20 Gig /dev/xvda. That's why I was looking at "how do I resize this thing safel?" Unfortunately, it doesn't help a lot with what I already have built, but could be useful going forward. ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] CentOS Images on AWS with partitions on /dev/xvda1 are awkwared to resize
to follow-up, I will give an example. Here is the listing for the official centos AMI: IMAGE ami-96a818feaws-marketplace/CentOS 7 x86_64 (2014_09_29) EBS HVM-b7ee8a69-ee97-4a49-9e68-afaee216db2e-ami-d2a117ba.2 aws-marketplace available public [marketplace: aw0evgkw8e5c1q413zgy5pjce]x86_64 machineebs hvm xen BLOCKDEVICEMAPPING EBS /dev/sda1 snap-591037fd 8 false standardNot Encrypted as you can see the block device mapping is by default set to BLOCKDEVICEMAPPING EBS /dev/sda1 snap-591037fd 8 false standardNot Encrypted it is a standard volume, not encrypted, and 8 GB my modification consists in adding this to my run command for my ami launch: -b /dev/sda1=snap-591037fd:20:false:gp2 I set the drive the same, the snapshot the same, and I give it 20GB instead of 8, I also use the gp2 type instead of the standard as well as telling it not to delete the volume when the instance terminates. Hope this helps. kp On Wed, 29 Apr 2015, Nico Kadel-Garcia wrote: I'm staring at the free CentOS images on AWS, and seeing that whoever set those up elected to use a partition for /dev/xvda1 rather than taking advantage of Amazon's tendency to use "/dev/xvda", "/dev/xvdb", etc. for each disk and use those directly as a file system. The result is that if you elect to allocate a larger base disk image, for example allocating 50 Gig to allow local home directories or space for "mock" or for bulky logs, and don't spend the time to select and allocate new disk images, it's awkward to simply expand the "/" partition. And with only 8 Gig allocated in the latest CentOS 6 images that I see in AWS, it's possible to get pretty pressed for space pretty quickly. Now, AWS published guidelines on manipulating partition size, and expanding a matching filesystem, but they're very clear to "unmount the parition before you touch it!!!" That's a bit difficult to unmount with a "/" partition, and they understandably don't have the kind of "boot from CD and work from the console" setup I'd normally use for that kind of work. So: why did the creators of that CentOS AMI elect to use such a small / partition? And how dangerous is it, with the system essentially idle, to use "parted" to expand the "/dev/xvda1" parition and then use "resize2fs" to expand the "/" file system while the system is alive? Note that, because I'm a complete weasel, I know at least one way around this: add a second disk, copy the OS to *that*, set grub to boot from the second disk, reboot from that, paritition the first disk as desired, copy the OS back, reset grub to boot from the first disk, and pray. I've had good success with the approach in the past, and have rebuilt rougly 15,000 Linux systems this way. But the work predates CentOS, and I dont't want to go through that again. So, has anyone resized "/" successfully and gracefully on AWS CentOS instances? Nico Kadel-Garcia ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] CentOS Images on AWS with partitions on /dev/xvda1 are awkwared to resize
This is not really a problem at all. when you launch your image for the first time, you can specify a larger / volume size and cloud-init-tools will take care of the rest. This is well documented in the AWS userguides. -- Kelly Prescott On Wed, 29 Apr 2015, Nico Kadel-Garcia wrote: I'm staring at the free CentOS images on AWS, and seeing that whoever set those up elected to use a partition for /dev/xvda1 rather than taking advantage of Amazon's tendency to use "/dev/xvda", "/dev/xvdb", etc. for each disk and use those directly as a file system. The result is that if you elect to allocate a larger base disk image, for example allocating 50 Gig to allow local home directories or space for "mock" or for bulky logs, and don't spend the time to select and allocate new disk images, it's awkward to simply expand the "/" partition. And with only 8 Gig allocated in the latest CentOS 6 images that I see in AWS, it's possible to get pretty pressed for space pretty quickly. Now, AWS published guidelines on manipulating partition size, and expanding a matching filesystem, but they're very clear to "unmount the parition before you touch it!!!" That's a bit difficult to unmount with a "/" partition, and they understandably don't have the kind of "boot from CD and work from the console" setup I'd normally use for that kind of work. So: why did the creators of that CentOS AMI elect to use such a small / partition? And how dangerous is it, with the system essentially idle, to use "parted" to expand the "/dev/xvda1" parition and then use "resize2fs" to expand the "/" file system while the system is alive? Note that, because I'm a complete weasel, I know at least one way around this: add a second disk, copy the OS to *that*, set grub to boot from the second disk, reboot from that, paritition the first disk as desired, copy the OS back, reset grub to boot from the first disk, and pray. I've had good success with the approach in the past, and have rebuilt rougly 15,000 Linux systems this way. But the work predates CentOS, and I dont't want to go through that again. So, has anyone resized "/" successfully and gracefully on AWS CentOS instances? Nico Kadel-Garcia ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
