Recreating the swap file if the current size is sufficiently larger #31
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…han the needed size
ee-gitbub
reviewed
Aug 4, 2023
| @@ -41,6 +41,7 @@ HIB_ENABLED_FILE = "hibernation-enabled" | |||
| IMDS_BASEURL = 'http://169.254.169.254' | |||
| IMDS_API_TOKEN_PATH = 'latest/api/token' | |||
| IMDS_SPOT_ACTION_PATH = 'latest/meta-data/hibernation/configured' | |||
| MAX_SWAP_SIZE_OFFSET_ALLOWED = 100 * 1024 | |||
There was a problem hiding this comment.
The offset is kept just to make sure that on every fresh start we are not recreating the swap. It is a limit that I am proposing to avoid unnecessary deletion of swap. But let me know if you feel otherwise
| @@ -467,7 +468,11 @@ def main(): | |||
| cur_swap = os.path.getsize(SWAP_FILE) | |||
|
|
|||
| bi = None | |||
| if cur_swap >= target_swap_size - SWAP_RESERVED_SIZE: | |||
| if cur_swap > target_swap_size - SWAP_RESERVED_SIZE + MAX_SWAP_SIZE_OFFSET_ALLOWED: | |||
There was a problem hiding this comment.
How was this scenario tested?
- Created a c5.xlarge instance.
- Made the changes in the hibinit file ( inside /usr/bin)
- Stopped the instance
- Modified to small instance( c5.large)
journalctl -b | grep hibinitto verify swap is recreated
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2457]: Effective config: {'grub_update': True, 'swap_percentage': 100, 'log_to_syslog': True, 'touch_swap': False, 'state_dir': '/var/lib/hibinit-agent', 'swapoff': 'swapoff {swapfile}', 'mkswap': 'mkswap {swapfile}', 'swapon': 'swapon {swapfile}', 'swap_mb': 4000}
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2457]: Found '/var/lib/hibinit-agent/hibernation-enabled', configuring hibernation
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2457]: Will check if swap is at least: 4000 megabytes
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2457]: Swap already exists! (have 8011616256, need 4194304000), deleting existing swap file /swap since current swap is sufficiently large and wasting memory
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2457]: Create swap and initialize it
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: kicking child process to initiate the setup
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: Allocating 4194304000 bytes in /swap
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: Swap pre-heating is skipped, the swap blocks won't be touched during to ensure they are ready
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: Running: mkswap /swap
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2457]: Setting up swapspace version 1, size = 3.9 GiB (4194299904 bytes)
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2457]: no label, UUID=f5142536-a989-42bc-95d0-cd971f491f57
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: Running: swapon /swap
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: Updating the kernel offset for the swapfile: /swap
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: Updating GRUB to use the device /dev/nvme0n1p1 with offset 265 for resume
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: GRUB configuration is updated
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: Setting swap device to 66305 with offset 265
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: Done updating the swap offset. Turning swapoff
Aug 04 18:19:03 ip-172-31-22-174.ec2.internal hibinit-agent[2462]: Running: swapoff /swap
- Verified it is successfully hibernated and resumed from hibernate
- Stop and start the instance again
journalctl -b | grep hibinitto verified no recreation. of swap occured
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: Effective config: {'grub_update': True, 'swap_percentage': 100, 'log_to_syslog': True, 'touch_swap': False, 'state_dir': '/var/lib/hibinit-agent', 'swapoff': 'swapoff {swapfile}', 'mkswap': 'mkswap {swapfile}', 'swapon': 'swapon {swapfile}', 'swap_mb': 4000}
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: Found '/var/lib/hibinit-agent/hibernation-enabled', configuring hibernation
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: Will check if swap is at least: 4000 megabytes
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: There's sufficient swap available (have 4194304000, need 4194304000)
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: Running: swapon /swap
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: Updating the kernel offset for the swapfile: /swap
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: Updating GRUB to use the device /dev/nvme0n1p1 with offset 265 for resume
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: GRUB configuration is updated
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: Setting swap device to 66305 with offset 265
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: Done updating the swap offset. Turning swapoff
Aug 04 18:23:17 ip-172-31-22-174.ec2.internal hibinit-agent[2452]: Running: swapoff /swap
- stop the instance
- Modified back to c5.xlarge
- Start the instance
journalctl -b | grep hibinitto verify swap is created due to larger swap required.
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2600]: Effective config: {'grub_update': True, 'swap_percentage': 100, 'log_to_syslog': True, 'touch_swap': False, 'state_dir': '/var/lib/hibinit-agent', 'swapoff': 'swapoff {swapfile}', 'mkswap': 'mkswap {swapfile}', 'swapon': 'swapon {swapfile}', 'swap_mb': 4000}
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2600]: Found '/var/lib/hibinit-agent/hibernation-enabled', configuring hibernation
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2600]: Will check if swap is at least: 7640 megabytes
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2600]: Swap already exists! (have 4194304000, need 8011620352), deleting existing swap file /swap
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2600]: Create swap and initialize it
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: kicking child process to initiate the setup
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: Allocating 8011620352 bytes in /swap
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: Swap pre-heating is skipped, the swap blocks won't be touched during to ensure they are ready
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: Running: mkswap /swap
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2600]: Setting up swapspace version 1, size = 7.5 GiB (8011616256 bytes)
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2600]: no label, UUID=757d742b-b666-4917-87fa-0b7a5418a983
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: Running: swapon /swap
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: Updating the kernel offset for the swapfile: /swap
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: Updating GRUB to use the device /dev/nvme0n1p1 with offset 57612 for resume
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: GRUB configuration is updated
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: Setting swap device to 66305 with offset 57612
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: Done updating the swap offset. Turning swapoff
Aug 04 18:25:03 ip-172-31-22-174.ec2.internal hibinit-agent[2605]: Running: swapoff /swap
- Verify hibernation and resume from hibernation is successful post that.
ee-gitbub
approved these changes
Aug 4, 2023
secarola
approved these changes
Aug 4, 2023
|
Got 2 approvals. Tested the same in instances |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Description of changes:
This Pull request adds a logic of deleting and recreating the swap file, if the current swap is larger than the needed size.
This will help wasting extra memory in storage and make it available to the user when modifying instances from larger to smaller type.
Testing: Tested the change internally inside an instance by modifying the file.