[Info-vax] Do VSI OpenVMS Drivers support Trim for SSD?

[Stephen Hoffman]

On 2024-02-29 06:55:01 +0000, John H. Reinhardt said:

> Cross posted from the VSI OpenVMS forum so if you have an answer, just 
> post where you are most comfortable. :D
> 
> As a hobbyist, looking to put standard commercial SSD (Samsung EVO, WD 
> Red, etc) in my Integrity rx2660. I already have some in my AlphaServer 
> DS10's as data disks (unbootable). Just wondering is trim is available 
> to help extend the life of the SSD.
> ...


The HP "solution" was to initialize storage sectors to zero, and to 
enable erase-on-delete to zero the deallocated storage, and to use an 
SSD with support for that.

Some of the HPE 3PAR storage hardware supported this, as did some other 
vendors.  Check the specs, or check with the SSD vendor.

Wikipedia references this particular practice, too: "Regardless of 
operating system, the drive can detect when the computer writes 
all-zeros to a block, and de-allocate (trim) that block instead of 
recording a block of zeros. If reading a de-allocated block always 
returns zeros, this shortcut is transparent to the user, except for 
faster writing (and reading) of all-zero blocks, in addition to the 
usual benefit of faster writing into unused areas. Operating systems 
don't write all-zeros to "wipe" files or free space, but some utilities 
do." And contrary to that last sentence, the operating system here can 
do exactly that.

This usage of writing sectors of zeros is different from writing 
sectors of zeros for data remanence, but unfortunately these two 
discussions tend to get tangled.

As mentioned elsewhere, no TRIM support in OpenVMS.


-- 
Pure Personal Opinion | HoffmanLabs LLC