I've never really understood what this icon, that looks like an oil drum

Database icon, from The Noun Project

and is commonly used to refer to a database, is actually supposed to represent.

What is it?

As a matter of fact, I've been searching for any kind of reading material about the history of the symbols commonly used in web app icons and haven't come up with anything helpful or interesting. Is there a good resource to read up on that?

  • 1
    three cans of chewing tobacco, alas not seen in workplaces anymore due to the tobacco-free laws. It means: you have to stay up late to fix the problems with the database, and you are not allowed to smoke in the machine room.
    – user67695
    Commented Aug 25, 2016 at 22:22
  • Answered on Stack Overflow: stackoverflow.com/questions/2822650/…
    – Vladislav
    Commented Oct 15, 2018 at 14:30
  • Maybe change your Accept checkmark to the actual answer? Commented Jun 17, 2021 at 19:15

5 Answers 5


It is a picture of a "disk pack" which is a stack of platters (usually 14 inch diameter) in a removable set. The original hard drives were the size of a washing machine, and had these swap-able packs. They had a clear plastic cover with a handle in the center, much like a cake carrier. You plopped it on to the drive, turned the handle to remove the cover, and then closed a door over the pack to enable the drive.

Amazing that people no longer know what they looked like. I made a clock where the dial was one of these big platters on which the head had crashed, leaving concentric marks in the orange surface (iron oxide). Of course, I had to be different, so I used a 168 hour motor and the "clock" showed the days of the week. Those synchronous motors are probably long gone also. They used to run all the stop lights.

enter image description here

enter image description here

  • Note distinction between "drive" and "disks" (platters). They didn't used to be one item, as today. The drive was a standalone unit, a motor and control mechanisms that spun platters & moved arms. In the 1970s when this icon started being used to represent databases in IS, (micro)computers lacked fixed secondary storage, and ran off main memory and temporary (floppy) storage. Mainframes, OTOH, were the go-to for any real computing, and had these large precursors to modern hard disks. Approximated as the physical incarnation of the DB; software was often bespoke before standardisation.
    – Engineer
    Commented Sep 14, 2018 at 12:25

It represents a stack of hard disks. For example, from wikipedia:

"RAID diagram icon symbolizing the array of disks"

enter image description here

Yes, this is talking about hard disks but the basic concept is the same.

  • Thanks. I'm still not clear on what/why it is what it is, but at least I get there's some kind of real world thing being referred to. Commented Jan 12, 2013 at 5:53
  • 3
    Nothing to do with RAID. The depiction goes way further back than the emergence of RAID. Well back into at least the early eighties of last century and probably even further. Commented Jan 12, 2013 at 8:15
  • @MarjanVenema yeah I know but it was the most relevant visual I could find that made the point
    – jlarson
    Commented Jan 12, 2013 at 19:11
  • Answer by a younger person who doesn't remember the original context. See user67695's answer, below, which I've edited to include pictures. See this image, or google "database stack platters".
    – Engineer
    Commented Sep 14, 2018 at 12:05

Historical reasons. It's just a simplified depiction of an actual hard disk. Remember that a single hard drive is actually made up of a stack of flat disks with the read/write heads in between the disks. A simpler depiction would be just a cylinder without the horizontal bands.


The American National Standards Institute (ANSI) set the standards for flowchart symbols in the 1960s - pre-dating hard disk drives. The standard memory in use at that time was drum memory - a precursor to disk drives - they were large metal cylinders coated in ferromagnetic recording material.

  • what makes you think that iconography follows ANSI standards? Most designers in Internet era didn't (don't) even know drum memory. I started in 1997 and never saw a drum memory!!
    – Devin
    Commented Nov 17, 2022 at 20:05

It’s a stack of platters that would be loaded into the drive mechanism. (Drums were represented by a horizontal cylinder.) The symbol dates from a ‘new’ 1969 ISO standard for flow chart symbols.IBM flowchart template 1969 In those days, through probably the new millennium, coding, business and system analysis were actually formal regimes when teams of people worked in parallel on projects and had to optimize limited resources. This changed in the ‘internet’ era with developers writing minimally viable and buggy code that will get tested by end users and (hopefully) fixed in the next sprint.

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