Have you ever gone on an all you can eat buffet and told yourself beforehand “I’m going to fill myself up”! I have. Long ago when I was still young, naïve, and doing my IT degree. It was an all you can eat dimsum buffet and I still remember forcing down that last dumpling that made me sick for the rest of the day.
Like everything else, sometimes there are limits that are best not to be pushed. In the IT world, Storage is always the first thing we test the limits on. These days when you buy 1TB of storage, you fill it up easily. You buy 50TB of storage and you still fill it up easily. You get a 100TB Shared SAN and you still fill it up easily. This is becoming our reality – the bigger the capacity, the more you fill it up!
In this month’s blog entry I won’t be talking about how to clean up or how to archive your data; I’ll be talking about what is best practice and what are the effects when you push the limits.
As a long time Storage Administrator, and many years of working for Digistor who is considered the leader in storage consultation and deployment; I can’t count how many times I’ve spoken with different storage and software vendors about recommended free space. Unfortunately I have seen too many horror stories where storage has reached capacity. Here is a summary of the information we gathered, and what Digistor suggest as best practice in maintaining storage capacity:
Soft Quota – 20% Free Space
Hard Quota – 10% Free Space
Alarming – below 5% Free Space
Bad – 0% Free Space
If your Storage is 20% above free space – that is good practice as it minimizes disk fragmentation and maintains performance.
If your Storage is below 20% but above 10% - that is within the soft quota and a clean-up needs to commence as soon as possible. Software/Storage Performance may or my not be guaranteed within this range.
If your Storage is below 10% - this is within the hard quota and commence a clean-up right away. Performance will drop and disk fragmentation will increase. Potential issues may arise such as drop frames, failed ingest, or slow read/write, slow file indexing.
If Storage is below 5% - this is an alarming state and you need to clean-up now. Expect performance drop, increase in disk fragmentation after initial clean-up, potential disk full messages on applications, drop frames, failed ingest, failed copy, slow file indexing.
If Storage is below 0% - All operations will fail and Filesystem may fail. Fragmentation will develop significantly on the first clean-up including free space fragmentation.
**Note that some shared storage offers virtual/dynamic data distribution which can maintain its performance and no fragmentation when reaching full capacity. However, software and some production workflow will still require space for operation and so low or full capacity can still impact your production.**If you find yourself having a hard time maintaining free space (which can result in production loss and downtime), speak with Digistor regarding options to increase your uptime and maximize your system’s performance.