On Mon, 3 Nov 2025 18:32:59 +0100 Tomek CEDRO <[email protected]> wrote:
> On Mon, Nov 3, 2025 at 6:06 PM Sulev-Madis Silber > <[email protected]> wrote: > > (..) > > the optical disks are most of cases readonly, they could retain data well, > > could be pressed into permanent disk, would be allowed in high security > > environments where usb would be not maybe > > > > i miss the optical use cases here, anyone give me insight? > > 1. read only / immutable. Some types of optical disks are re-writable, while most of writable optical disks are write-once. And re-writable disks are roughly categorized into two. a) Erase and write for the whole disk at once. (Example: CD-RW and DVD-RW) b) Can read/write just like a HDD. (Example: MO, PD, DVD-RAM) IIRC, DVD-RAM needed to be formatted and written as UDF, while MO and PD were mimic'ing HDD and partitionable. > 2. no moving parts = immune to mechanical malfunction like hdd. MO, PD and some of DVD-RAM media are provided as "cartridges" and had shutter on access hole. https://en.wikipedia.org/wiki/Magneto-optical_drive https://en.wikipedia.org/wiki/Phase-change_Dual https://en.wikipedia.org/wiki/DVD-RAM > 3. no electronics parts = immune to esd / emp like ssd. > 4. long life time far exceeding hdd/ssd (i.e. hard coat, or mdisk). > 5. small and light. > > -- > CeDeROM, SQ7MHZ, http://www.tomek.cedro.info -- Tomoaki AOKI <[email protected]>
