Installing to flash disk gives you an option to install with an "n" option. Once installed in this manor the drive is protected from any changes, a reboot reverts the drive to just as it was. Now is there a way to change the umask=000 so that the drive can have changes made from time to time but locked down the rest of the time. I have young students that use the notebooks and the write protection is great until I need to add something.
LSI 9305-16i SATA SAS 12Gbs RAID Controller PCIe 3.0 x8 IT-Mode 4* 8643 SATA
$229.99
SanDisk Professional 48TB G-RAID Shuttle 4, External HDD - SDPH34H-048T-NBAAB
$2799.99
OWC ThunderBay 4 RAID 5 with Dual Thunderbolt 3 Ports (24TB-Enterprise)
$1099.99
Yottamaster 2 Bay 3.5" RAID Hard Drive Enclosure USB 3.1 for SATA SSD HDD 32TB
$75.99
Inspur LSI 9300-8i Raid Card 12Gbps HBA HDD Controller High Profile IT MODE
$15.98
ORICO Multi Bay RAID Hard Drive Enclosure USB 3.0/ Type-C For 2.5/3.5'' HDD SSDs
$86.99
LSI MegaRAID 9361-8i 12Gb PCIe 8-Port SAS/SATA RAID 1Gb w/BBU/CacheVault/License
$35.96
LSI MegaRAID 9361-8i 12Gbps PCIe 3 x8 SATA SAS 3 8 Port RAID + BBU & CacheVault
$39.00
ACASIS 2.5/3.5 inch 2 Bay SATA USB 3.0 Hard Drive Disk HDD SSD Enclosure 4 RAID
$58.99
Yottamaster 5 Bay RAID Hard Drive Enclosure USB3.1 Type C 2.5"/3.5" SATA HDD SSD
$142.49