OSGeo6 new SSD disks for SAC

[Grant Slater]

Hi Sac,

Friendly outsider OSM sysadmin here...

Samsung does make good disks, but I wouldn't recommend the Evo or QVO
ranges for critical data services, unless you are willing to accept
data loss.
Why?
1) EVO and QVO use small internal caches to improve write performance
to the slow TLC flash, under sustained writes the performance can
become very poor.
2) The EVO and QVO ranges are liable to write cache loss (1 from
above) or corruption if power is unexpectedly lost. It can cause the
entire disk to become unusable. Only the Pro or DCT ranges have power
loss protection.
3) Lower TBW, normally no longer an issue, but write amplification in
RAID5 or RAID6 can significantly bloat the TBW figure.

If the budget is tight, I'd instead recommend getting Pro or Data
Centre editions disks from resellers. Ideally before disk enters
service upgrade the firmware, trim/discard the whole disk (blkdiscard)
and confirm a suitable write endurance is left on the disk.
Here is the list of SSDs we use in OpenStreetMap:
https://prometheus.openstreetmap.org/d/-Rfv28pGz/ssds

Kind regards,

Grant

On Tue, 30 Sept 2025 at 13:41, Regina Obe <lr at pcorp.us> wrote:
>
> In reviewing for 2.5" SATA SSDs to replace the 450GB disks currently in
> OSGeo6.
>
> https://lists.osgeo.org/pipermail/sac/2025-September/016850.html
>
> I came across these which don't seem too too expensive and still a decent
> brand.
>
> https://www.amazon.com/SAMSUNG-Inch-Internal-MZ-77E1T0B-AM/dp/B08QBL36GF/ref
> =sr_1_1?crid=2GY3TIQOCCXY4&th=1
>
> I think it makes sense to replace all 6 disks.
> Options that seem better than what we have.
>
> 1TB ~$100 per disk -- $600
> 2 TB ~170 per disk --  $1020
> 4 TB ~ $370 per disk - $2220
>
> I'm thinking the 2TB to give us 12TB   which comes down to like 6TB - 8TB of
> usable space I think with whatever RAID we decide to go with.
>
> I'm not sure it makes sense to spend $2000 on such an old server.
>
> However we will be getting rid of osgeo3 and osgeo4, so we have to keep that
> in mind too.
> Osgeo8 I'm thinking is the best server to replace osgeo4 and move much of
> osgeo3 and osgeo8 stuff to osgeo6 or osgeo7
>
> Thoughts,
> Regina
>