There is a soft 2 TB boundary and a hard 10 TB boundary. They are defined by physics, so they are not negotiable and cannot be removed by throwing money at it.
When you reach these sizes, talk to your DBA about alternatives. Treat the 2TB boundary as a complexity inflection point, and use the remaining time as runway to branch out into alternative solutions.
These calculators require the use of Javascript enabled and capable browsers. Compare information of original equipment tire size and alternate after market tire sizes. There are two flavors, one for U.S. designation tires and one for metric TRX designation tires. All calculations are designed to round up. Calculations are to be treated as approximate only, due to possible and probable variations in how tires are manufactured. The information in the Required area is needed to perform the comparison. The tire tread width, sidewall (aspect) ratio, and wheel rim diameter from each of the two tires to be compared, along with a speedometer reading used to compute the effect the after market tire size has on your speedometer's accuracy. The following is an example to help to decode a tire size like 195/70R15. The 195 is the tire width in millimeters, measured from the bottom of the bead to the bottom of the bead, the 70 is the sidewall aspect ratio, the ratio of sidewall height to tire width at the tread (indicating that the sidewall height is 70% of the tread width), and the 15 is the wheel rim diameter in inches. After the data entry of the required information, click on the Compare U.S. Tires button in the top calculator or Compare Metric Tires in the lower calculator to have the selected tire sizes compared. Adjusted Speedometer Reading is what speed the car will need to go if using the after market tires, to be traveling at the same speed if the car had the original tires on. It is an adjustment faster or slower from the original speed. Please select from U.S. or Metric comparisons.
One of our customers had a question related to the right value of Galera Cache size (gcache.size) in Galera Cluster for MySQL which I would like to share with you.
The question was: My maintenance window takes 4 hours for my 5TB DB. How can I avoid an SST ?!
Basically, having too small GCache size will lead to SST (Snapshot State Transfer) instead of IST (Incremental State Transfer), thus we can avoid the SST by setting the GCache to the appropriate value.
State Snapshot Transfer (SST) is a way for Galera to transfer a full data copy from an existing node (donor) to a new node (joiner). If you come from a MySQL replication background, it is similar to taking a backup of a master and restoring on a slave. In Galera Cluster, the process is automated and is triggered depending on the joiner state.
SST can be painful in some occasions, as it can block the donor node (with SST methods like mysqldump or rsync) and burden it when backing up the data and feeding it to the joiner. For a dataset of a few hundred gigabytes or more, the syncing process can take hours to complete - even if you have a fast network. It might be advisable to avoid e.g. when running in WAN environments with slower connects and limited bandwidth, or if you just want a very fast way of introducing a new node in your cluster.