Disk size and storage
How full the disk is, how big it may get, dynamic versus fixed, and automatic growth.
On this page 5 sections
The Storage card on the Overview tab shows how full an instance's disk is and sets how big it may get.
Reading the card#
- The usage bar — "X used inside name" and "N% of total", with when it was last measured. The bar turns orange once the disk is 85% full. Until the instance has run once, it says "Start this instance once and MSL will measure how full it is."
- Guest disk size — how big Linux thinks its disk is.
- Actually used on your Mac — what the image file really takes on your Mac right now. For a dynamic disk this is usually far smaller than the disk size; a fixed disk adds "(reserved)".
Dynamic or fixed#
| Dynamic (the default) | Fixed | |
|---|---|---|
| On your Mac | Takes only the space Linux has actually written. | Reserves the whole size up front. |
| The slider sets | the Limit | the Size |
| Good for | Almost everyone. | Making sure the space is there, however full your Mac gets. |
A new disk is dynamic, with a 64 GB limit.
Making it bigger#
Drag the slider (4 GB to 512 GB, in steps of 4) and let go. If the instance is stopped, the image grows right away; if it's running, the change waits for its next start. Either way, Linux's filesystem is stretched to fill the new size during the next start, and until then the card says "The guest filesystem is extended the next time this instance starts."
Growing automatically#
With a dynamic disk, Grow automatically when it runs low (on by default) looks after a disk that's smaller than its limit: whenever the instance starts with its disk at least 85% full, MSL grows it by 8 GB, up to the limit. When it's already at the limit, nothing grows and the log notes it.
Your Mac's free space#
The footnote shows how much space is free on your Mac. A dynamic disk can't grow past what your Mac has room for, so keep an eye on both. See The disk is full.