no-shred: cache frequent writes - PVE
UNRELEASED
Warning
Non-production quality tooling, please use ONLY for testing purposes.
Proxmox Cluster Filesystem holds the content of vital configurations in the mountpoint of /etc/pve. The backend is held in SQLite database residing on the OS disk under /var/lib/pve-cluster - this can be mounted over to RAM sparing the actual block layer of getting hit by the constant barrage of tiny write operations. The RAM hosted backend is flushed into the original location in regular intervals. Side effect of this setup is higher resiliency against database corruption as the flush operation is atomic.
Apart from this, configuration of rrdcached is also optimised for infrequent disk writes.
Quickstart
Download
wget -P /tmp https://dist.free-pmx.org/free-pmx-no-shred_0.1.0-20250509-TEST.debInstall
apt install /tmp/free-pmx-no-shred_0.1.0-20250509-TEST.debImportant
It is necessary to reboot the host after install for the caching to take effect.
Remove
apt purge free-pmx-no-shredWarning
It is necessary to reboot the host after uninstall. On single-node deployments, failure to do so will result in LOSS of configuration changes that occurred between uninstall and subsequent reboot.
Audit
How to check what’s inside a debian package.
Known limitations
Currently, it is necessary to reboot the host before and after install/uninstall. It is also not possible - as a pre-caution - to manually start or stop the no-shred service.
There is no monitoring of e.g. failing timer with any notifications.
Furthermore, there is a timeout set should the service fail to start during boot. The setup allows for the node to gracefully continue booting, but it will be booted up without caching, i.e. with stock Proxmox services directly writing onto disk.
Disclaimer
THE TOOL IS A THIRD-PARTY PRODUCT AND IS PROVIDED ON AN “AS IS” BASIS AND WITHOUT WARRANTIES OF ANY KIND EITHER EXPRESS OR IMPLIED, STATUTORY OR OTHERWISE.