How do other organizations deal with this? I do more or less what you’re doing. Keeping snapshots around for a few days for a specific reason isn’t bad. You just need to make sure to not forget about them and let them “rot” for any longer than is needed. I have my monitoring system set … Read more
No, it’s not. What happens when your filesystem or RAID volume gets corrupted? Or your server gets set on fire? Or someone accidentally formats the wrong array? You lose all your data and the not-real-backups you thought you had. That’s why real backups are on a completely different system than the data you’re backing up … Read more
The ResearvationId has nothing to do with Reserved Instances. It is a unique value indicating a request to launch EC2 instances. A launch request may come from the cli, AutoScaling, or the AWS Management Console. Each request to aws ec2 run-instances will return zero or more reservations of instances. Usually, it’ll be one if it … Read more
Why not have a look at the snapshots section of the LVM-HOWTO? LVM snapshots are your basic “copy on write” snapshot solution. The snapshot is really nothing more than asking the LVM to give you a “pointer” to the current state of the filesystem and to write changes made after the snapshot to a designated … Read more
When a VM has an active snapshot, its virtual disk I/O is not performed on the VM’s actual .VMDK files, but instead they are kept unchanged, and whatever changes in the VM is written to different physical files; this allows for the recovery of the previous VM state, but has three important side effects: Disk … Read more
When you create a snapshot, the original disk image is “frozen” in a consistent state, and all write accesses from then on will go to a new differential image. Even worse, as explained here and here, the differential image has the form of a change log, that records every change made to a file since … Read more
Most of these snapshots are copy-on-write snapshots, which are really fast and really cheap (storage-wise) on rarely-updated systems. LVM snapshots are COW snapshots, ZFS/BTRFS both have a COW-mode for snapshots, reiserfs doesn’t have snapshots natively, Novell’s NSS file-system is also COW, as are Shadow Copy volumes for Windows NTFS volumes. Copy-on-write snapshots take a copy … Read more
You’re safe to use the volume once you have triggered the snapshot, even if it’s still in a pending state according to AWS – see this post. If you’re taking a snapshot for the first time, it probably will take a while as it has to make a full copy to the region-wide S3 bucket, … Read more