Your Set-Top Box Will Now Support more DTH Operators

October 22, 2021 in Technology, Tips and Tricks

What is the difference between init 6 and reboot

Reboot

reboot uses the shutdown command (with the -r switch). The shutdown command used to kill all the running processes, unmount all the file systems and finally tells the kernel to issue the ACPI power command.

Init 6

init 6 tells the init process to shutdown all of the spawned processes/daemons as written in the init files (in the inverse order they started) and lastly invoke the shutdown -r now command to reboot the machine

October 20, 2021 in Technology, Tips and Tricks

why swap memory not used with ssd

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SSD Endurance is measured in so called DWPD units. DWPD stands for Drive full Writes Per Day. For Mobile, Client and Enterprise Storage Market segments DWPD requirements are very different. SSD Vendors usually state warranty as, for example, 0.8 DWPD / 3 years or 3.0 DWPD / 5 years. First example means that writing 80% of Drive Capacity every single day will result into 3 years life-time. Technically you can kill your 480GB Drive (let’s say with 1 DWPD / 3 years warranty) within 12 days if to perform non-stop write access at the speed of 500 MB/s.

SSDs show much higher throughput on the one side if to compare with HDDs, but at the same time quite low endurance level. Partially it is due to the media physical structure and mapping. For example, when writing 1GB of user data to the HDD drive – internally physical media will receive around 10% more data (meta data, error protection data, etc.). Ratio between Host Data Amount and Internal Data Amount is called Write Amplification Factor (WAF). In comparison SSD may need to write 4 times more data than received from Host. Pure Random access is the worst scenario, when writing 1GB of Host Data will result into writing 4GB of data to the Internal Flash Media. If to perform only sequential write access WAF for SSDs will be close to 1.0, like for HDDs.

Enabling System swap and its intensive usage (probably due to DRAM shortage) will generate more Random access to the SSD. Endurance will degrade quicker if to compare with disable swap. Unless you are running Enterprise System with non-stop IO traffic to the SSD, I would not expect Swap enablement to affect SSD endurance much. You can always monitor SSD SMART Health parameter called – SSD Life Left. How it is changing in dynamic with/without swap enabled will help to make a decision.

October 20, 2021 in Technology, Tips and Tricks

How To Add Swap on CentOS 7

Although swap is generally recommended for systems utilizing traditional spinning hard drives, using swap with SSDs can cause issues with hardware degradation over time. Due to this consideration, we do not recommend enabling swap on DigitalOcean or any other provider that utilizes SSD storage. Doing so can impact the reliability of the underlying hardware for you and your neighbors.

If you need to improve the performance of your server, we recommend upgrading your Droplet. This will lead to better results in general and will decrease the likelihood of contributing to hardware issues that can affect your service.