[j-nsp] Junos: snapshot ?

[R S]

A customer of mine runs MX960 (dual RE), SRX5800 and SRX3600 (cluster with dual RE), EX8200 (dual RE) and EX4200 (in VC), in the weekend will run a disaster recovery test powering off those devices.
I’d like to avoid any problem with files corruptions, which is the safer command to use to save current file systems of those devices family ?

request system snapshot  <enter>

Can I ask to run this command in production time on all the mentioned devices ?

Any additional suggestion ?

Tks