ruga at protonmail.com
Tue Jun 30 11:52:28 UTC 2020
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Sunday 28 June 2020 21:29, Matthias Schniedermeyer <ms at citd.de> wrote:
> On 28.06.2020 16:46, Rupert Gallagher wrote:
> > ????????????????????? Original Message ?????????????????????
> > On Sunday 28 June 2020 13:58, Matthias Schniedermeyer ms at citd.de wrote:
> > destination:
> > ST5000LM000-2AN1 sata hdd
> > Writing speed : 74 MB/s
> > Reading speed : 89 MB/s
> And this HDD is a SMR model(*) on top of beeing a 4k sector model emulating 512 byte sectors.
> So alignment needs to be correct and the filesystems must use 4k sectors.
> This HDD is NOT suitable for beeing used for small files and a hardlink-farm.
> SMR HDDs only reach best performance if used "like a tape drive" with large and linear writing.
> I use SMR HDDs myself and only use them for "really large" files (>500MB per file), otherwise they perform very poorly.
> I also align my partitions correctly and set XFS to "4k sector"-size.
> Which nowadaya means: I use 4k sectors for anything. As i only have been
> using 4k sector HDDs for nearly as long as they are on the market (IIRC >1 decade).
> Also SSDs are usually optimized for 4k sectors too.
SMR is the cost we pay for large storage on small space.
There is something similar to SMR also for SSD, found in Samsung QVO units.
The cost-benefit analysis for 2.5" drives led to this product.
Costs are HDD <= SSD < TAPE (HP LTO Ultrium).
We are using this disk "like a tape drive", with hardlinks because it can.
This is from the current disklabel:
total sectors: 9767541168 # total bytes: 4.5T
This is from the current ffs2:
fs block size : 8192 bytes
Free disk space : 4713572474880 bytes
The values are native, without any tuning.
However, the bottom line is that I get the job done in 2 hours via the lan, and 8 hours via the bus...
More information about the rsync