For the current instance you have to create volumes on EBS and attach them to the instance.<\/div>\n
2. Install mdadm for RAID: sudo apt-get install mdadm<\/strong> (Choose e-mail configuration during install – I chose No configuration)<\/p>\n3. The next step – check that Ubuntu doesn’t mount these disks automatically – I don’t know why Ubuntu mount it, so, unmount them if needed and edit fstab:<\/div>\n
sudo umount \/mnt<\/strong><\/div>\n<\/div>\n
4. Create RAID10:<\/div>\n
sudo mdadm –create –verbose \/dev\/md0 –level=10 –raid-devices=4 \/dev\/xvd[b-e]<\/strong><\/div>\n<\/div>\n
5. Monitor the creation:
sudo cat \/proc\/mdstat <\/strong>or sudo watch cat \/proc\/mdstat
\n<\/strong><\/div>\n<\/div>\n
6. Update initramfs to up RAID after reboot:<\/div>\n
sudo update-initramfs -u<\/strong><\/div>\n<\/div>\n
7. Format the new disk:
sudo mkfs.ext4 \/dev\/md0<\/strong><\/div>\n<\/div>\n
8. Edit mdadm.conf:<\/div>\n
get UUID from
sudo mdadm -Db \/dev\/md0<\/strong><\/div>\nand add to mdadm.conf the next e.g.:<\/div>\n
\nDEVICES \/dev\/xvdk \/dev\/xvdh \/dev\/xvdi \/dev\/xvfl<\/div>\n
ARRAY \/dev\/md0 level=10 num-devices=4 metadata=1.2 UUID=2cfdb9f9:4126fc1b:3c32dc68:473d8c4e<\/div>\n<\/blockquote>\n
<\/div>\n
9. Edit fstab:<\/div>\n
sudo echo “\/dev\/md0 \/usr\/data ext4\u00a0defaults,nobootwait,noatime 0 0”<\/strong><\/div>\n(\/usr\/data – mount point)<\/div>\n
<\/div>\n
10. Make changes in \/etc\/initramfs-tools\/conf.d\/mdadm to allow boot with degraded RAID:<\/div>\n
sudo nano \/etc\/initramfs-tools\/conf.d\/mdadm<\/strong><\/p>\n# BOOT_DEGRADED:
\n# Do you want to boot your system if a RAID providing your root filesystem
\n# becomes degraded?
\n#
\n# Running a system with a degraded RAID could result in permanent data loss
\n# if it suffers another hardware fault.
\n#
\n# However, you might answer \u201cyes\u201d if this system is a server, expected to
\n# tolerate hardware faults and boot unattended.
\nBOOT_DEGRADED=yes<\/p><\/blockquote>\n<\/div>\n
For Red Hat and etc you need run the command dracut -f<\/div>\n
\n
What you need to do is something like this:<\/p>\n
mkinitrd \/boot\/initrd-<kernel-version>.img <kernel-version>\r\n<\/code><\/pre>\nI’m assuming here that the CentOS version you’re using is still using mkinitrd<\/code> – if it has switched to dracut<\/code> then you will want:<\/p>\ndracut \/boot\/initramfs-<kernel-version>.img <kernel-version>\r\n<\/code><\/pre>\n<\/div>\n11. For getting e-mails about raid status you can add string like this MAILADDR mail@domain.com into mdadm.conf. You must have sendmail or another e-mailer.<\/div>\n
<\/div>\n
12. Reboot and check.<\/div>\n
13. Conclusions:<\/div>\n
1. I did it in Ubuntu 12\u00a0 on the Amazon. I tried make RAID10 but it didn’t up after reboot and I lost the access to instances.<\/div>\n
So, I detached disk from instance, made a new instance in the same location us-east-1b and attached disk to the new VM, edited \/etc\/fstab, detached the disk again and attached it to the old instance (\/dev\/sda1 by default – check it before detaching) – I got the instances back and rebuild RAID sucessfully.<\/div>\n
2. If you have problems with raid and system doesn’t boot, you can detach disk and attach to another VM, then mount it and chroot. Then do some changes and do update-initramfs -u, then attach it to source VM.<\/div>\n
3. Make RAID only with EBS disks because internal (ephernal) disks will be cleaned after stop.<\/div>\n
<\/div>\n
Script for temp disks:<\/div>\n
\n#!\/bin\/sh<\/div>\n
sudo mdadm –force –run –create –verbose \/dev\/md0 –level=10 –raid-devices=4 \/dev\/xvd[b-e]<\/div>\n
mkfs.ext4 \/dev\/md0<\/div>\n
mount \/dev\/md0 \/usr\/data<\/div>\n<\/blockquote>\n
<\/div>\n<\/div>\n<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"
I had to add Raid to the EC2 instance with Ubuntu. I chose RAID10. So, 1. Add disks to the instance (I added 4 disks for RAID10): Adding Instance Store Volumes to an AMI Amazon EBS-backed AMIs don’t include an instance store by default. However, you might want instances launched from your Amazon EBS-backed AMIs […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14,6,13],"tags":[],"class_list":["post-472","post","type-post","status-publish","format-standard","hentry","category-amazon","category-linux","category-novosti"],"_links":{"self":[{"href":"https:\/\/dety.net.ua\/index.php?rest_route=\/wp\/v2\/posts\/472","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dety.net.ua\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dety.net.ua\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dety.net.ua\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dety.net.ua\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=472"}],"version-history":[{"count":9,"href":"https:\/\/dety.net.ua\/index.php?rest_route=\/wp\/v2\/posts\/472\/revisions"}],"predecessor-version":[{"id":504,"href":"https:\/\/dety.net.ua\/index.php?rest_route=\/wp\/v2\/posts\/472\/revisions\/504"}],"wp:attachment":[{"href":"https:\/\/dety.net.ua\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=472"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dety.net.ua\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=472"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dety.net.ua\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=472"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"Instance](\"http:\/\/docs.aws.amazon.com\/AWSEC2\/latest\/UserGuide\/images\/create-image-instance-store.png\")
<\/div>\n<\/blockquote>\n