We are setting up a new SQL Server with over 2 TB size of Database, and this is a heavy OLTP. Let me know, if there is any impact of placing SQL binaries in C drive? or i would need another Drive? Server is already having these drives

SQL Server databases data files – G SQL Server database log files – L TempDB data file(s) – T (local drive) Backups – H:

And these are Pure FlashArray storage mounted onto Windows. SQL server 2017 Standard version will be installed on MS Windows Server 2016 Standard.

Your help is really appreciable. Let me know, if you need any other details? Also let me know, any best practice for SQL installation.

  • 'S, Welcome to the site, it's always safe side to side sql server data and log files other than c drive. – Md Haidar Ali Khan Apr 16 at 15:03
  • 1
    Yes, leave the binaries on the C drive. There are several things you won't be able to put elsewhere anyway. – Aaron Bertrand Apr 16 at 15:06
  • @AaronBertrand What can’t you put elsewhere? Not to say I don’t believe you, but I don’t remember seeing this limitation before. – John Eisbrener Apr 17 at 0:07
  • @JohnEisbrener Try it. You can tell all the options to install on another drive and you'll still end up with many things that are hard-coded to C:\ – Aaron Bertrand Apr 17 at 0:25
  • Ah yes, dlls, setup bootstrap log files, and some other miscellaneous files. Things I always forget about since they tend not to cause to many issues or increase in size over time. – John Eisbrener Apr 17 at 14:40

The binaries can live on C:\ or another system drive (though said drive should be formatted using the default block size). My personal preference is to place them on another system drive (again, formatted using the default block size) because of the following reasons:

  1. The page file, by default, resides on the C:\ drive
  2. Other processes keep all manner of junk on the C:\ drive, by default (e.g. Windows patches, C:\Temp, etc.)
  3. SQL Server log files are written to where the binaries are installed, by default
  4. I'm lazy and don't want to do a whole bunch of post-install reconfiguration, and this also makes it easier for future DBAs to find where the SQL-related log files are located in the event of an outage, etc.

The main point here is that between the page file, patching, etc. the C:\ drive can be utilized by processes outside of your control as a DBA. The problem with keeping the SQL Server log files on the same drive as these other things is that over time this drive can (and generally does) get crowded which can potentially cause a system outage if it becomes full and you can't write to it.

Regardless where you install binaries, I also recommend you make sure the system databases (e.g. master, msdb, model) are located on your data drive. If they're also located on the C:\ drive, they too can contribute to disk crowding with their growth over time. Finally, just make sure the block size for the disks hosting database files (e.g. mdf, ldf, and backup files) are all formatted with 64Kb block size. It's much more of a pain to make this happen after you lay down the binaries than before.

Final note; as pointed out by Aaron Bertrand in the comments, there are still some files that will always be created on the C:\ drive, such as various dlls and the Setup Bootstrap log files. Leave those alone as they are necessary to keep your service running, but for me, moving most of my SQL Server Binaries off of the C:\ drive often proves beneficial in the long run.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.