> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vast.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Set a Maintenance Window
> Schedule a maintenance window on one machine or on many at once from the Machines page, so renters are warned before you take hardware down.
A maintenance window tells renters that you are going to take a machine down. When
you schedule one, everybody with a running or stopped instance on that machine is
notified with the start time and duration, and a warning appears on their instance
card so they can save their work.
Scheduling a window is a notification, not an action. It does not stop instances,
unlist the machine, or block new rentals. You still take the machine down yourself
when the window arrives.
The screenshots on this page use the redesigned **Machines** page, which is
currently in Early Access. See [Using the classic Machines page](#using-the-classic-machines-page)
if you have not opted in — the steps are nearly the same, but you cannot set a
reason.
***
## Set a window on one machine
Go to [Host → Machines](https://cloud.vast.ai/host/machines/) and find the
machine you want to take down.
Click **Settings** on the machine's card.
The settings dialog opens on **Listing Settings**. Switch to **Machine
Maintenances**.
Fill in all three fields:
* **Maintenance start** — the date and time the machine goes down. It
defaults to 24 hours from now.
* **Duration (hours)** — how long the machine will be unavailable, as a
whole number of hours.
* **Reason** — what the maintenance is for. See
[Reasons](#reasons) for the full list.
**Add** stays disabled until the duration is a positive whole number and a
reason is selected. Once you click it, the window is created and renters are
notified.
The new window appears in the table below the form, marked **Upcoming**.
***
## Set one window across several machines
If several machines go down together — a rack, a circuit, everything behind one
switch — you can schedule a single window for all of them in one pass.
Tick the checkbox on each machine you want to include, or use **Select all**
to take every machine in the current view. A bar appears showing how many are
selected, with a **Bulk Edit** button on the right.
The same settings dialog opens, titled with the number of machines selected
instead of a single machine ID.
Go to **Machine Maintenances** and fill in the start, duration, and reason
exactly as above, then click **Add**. Every selected machine gets the same
window, and renters on all of them are notified.
The list below the form gains a **Machine** column so you can tell the
windows apart, and a summary tells you which machines succeeded and which
failed.
A bulk request covers at most 100 machines. Select fewer and repeat if you have
more than that.
***
## Review or cancel a window
The **Machine Maintenances** tab lists every window on the machine, past and
upcoming, with a status:
| Status | Meaning |
| ------------- | ------------------------------ |
| **Upcoming** | Scheduled, has not started yet |
| **Ongoing** | The window is open now |
| **Completed** | The window has passed |
To cancel a window, click the **✕** at the end of its row. Upcoming and ongoing
windows can be cancelled; completed ones cannot.
A window that Vast scheduled on your machine cannot be cancelled from this page.
Contact support if one needs to be removed.
***
## Field reference
### Start time
The start must be in the future, and no more than a year out.
### Duration
Duration is recorded in whole hours, with a minimum of one. A fractional value is
rounded down, so anything under an hour becomes one hour.
### Reasons
| Reason | Use it for |
| ------------------- | ----------------------------------------------------- |
| **Power issues** | Electrical work, UPS or PDU changes, a planned outage |
| **Internet issues** | Switch, router, uplink, or ISP work |
| **Disk issues** | Replacing or rebuilding storage |
| **GPU issues** | Pulling, replacing, or reseating a GPU |
| **Updates** | Driver, kernel, or host software upgrades |
| **Other** | Anything that does not fit the above |
***
## Using the classic Machines page
The redesigned Machines page is opt-in while it is in Early Access. To turn it on,
open [Account Settings](https://cloud.vast.ai/account/), find the **Early Access**
section, and enable **Machines page**.
You get there the same way: **Settings** on a single machine, or **Bulk Edit**
once you have selected several. The dialog is what differs. It has no tabs — the
window is set from a **Set Machine Maintenance** section partway down it — and it
has no **Reason** field, so every window scheduled there is recorded as
**Other**. Set the start date and **Duration (hours)**, then click **Schedule
Maintenance**.
Existing windows appear under **Scheduled Maintenances**, with a **Category**
column that shows the stored value rather than the label used on the redesigned
page — a window set to **Updates** reads as `software` here.
***
## Related
* [Host notifications](/host/notifications) — control how maintenance
confirmations reach you
* [`vastai schedule maintenance`](/host/cli/schedule-maint) — schedule a window
from the CLI
* [`vastai show maints`](/host/cli/show-maints) — list scheduled windows
* [`vastai cancel maint`](/host/cli/cancel-maint) — cancel a machine's windows
* [Upgrade the Kernel](/host/upgrade-kernel) — a task that needs a window first