Sql-server – MSDB log file size

You should be aiming to auto-grow as little as possible. Seven times a day is excruciating, even with instant file initialization.

Don't do a Shrink Database. Ever. Shrinkfile, maybe, but only after an extraordinary event. Shrinking it just to grow again is an exercise in futility and should actually be called auto-fragment.

If recovery model is simple, there is no way on earth you should need to grow your log file by 250 GB. The used space in the file will clean itself out automatically over time, unless you started a transaction a month ago and have no intentions of ever committing it or rolling it back.

So my advice would be:

Auto-grow the data file manually during a quiet period to a size that will accommodate several months of growth. What are you saving it for in the meantime?

Set the auto-growth increment for the data file to something relatively small (so that it doesn't interrupt users when it does happen), and alert on this event (you can catch it in the default trace, for example, or through extended events). This can tell you that you are hitting the high point you estimated and it is time to grow manually again. At this point you will want to keep this manual in case you want to add a new file / filegroup on a different drive to accommodate the space, since eventually you will fill the current drive.

Auto-grow the log file to, say, twice the largest it's ever been. It shouldn't auto-grow further unless there is some abnormal transaction holding things up. You should monitor for this event as well, so that you know about them.

A single transaction log file has both a physical size (that you see on disk), and it's also broken down within the physical file into logical sections called virtual log files (VLFs).

Both auto-growth and auto-shrink operate on the physical transaction log file.

Transaction log truncation (also called "log clearing") operates on the logical sections of the transaction log (VLFs), and does not affect the physical file size. This part is frequently the subject of confusion.

A log file must always grow to accomodate a large transaction; turning off auto-shrink will leave the log file with its maximum needed size, instead of physically decreasing its size.

If you don't have large transactions, it will be safe to disable auto-shrink; the log files will not grow without bound like would happen if the database was in FULL or BULK_LOGGED and you weren't taking transaction log backups.

This behaviour is the same for SQL Server 2005+.