A couple of questions about SSDs

[Steve O'Hara-Smith]

On Wed, 14 Oct 2020 20:22:06 +0200
Ralf Mardorf <ralf-mardorf at riseup.net> wrote:

> As soon as I've got enough money again, I will get also more external
> storage space. Maybe I'll continue using USB (/eSATA) enclosures, maybe
> I'll get a swap bay. I've got no experiences with NAS. It seems to be
> too expensive. However, a starting point would be to replace my 1 and 2
> TB external HDDs with 4 TB HDDs. The used enclosures are suitable for
> HDDs up to 4 TB.

	A NAS is just a computer with a lot of storage serving it up over
the network by NFS and/or SMB. A FreeBSD NAS is usually ZFS based with
either mirrors (better performance, faster resilver) or some level of RAIDZ
(better storage efficiency). No matter what level of redundancy in the NAS
you still want a backup which adds up. I currently use a refurbished 1U
server[1] with eight second hand 3.5" 2TB SAS drives[2] arranged as four
mirrors for my NAS (it cost about £500 all in a couple of years ago) and an
old Atom box with four hot swap SATA bays set up as a RAIDZ for the
backup[3].

[1] Half the cores turned off and the clock locked to minimum brings the
power consumption and fan noise down to sane levels while still being able
to saturate the dual LAN from encrypted drives.
[2] By data centre standards these are slow low power drives so they
got used for nearline, backup and low load servers, they get very low usage
before being retired by age policy. By home user standards they're fast
high quality drives. One of the better storage bargains.
[3] Yes the backup has less capacity than the main NAS, I'll need to worry
about that in a few years time at current usage growth rates.

-- 
Steve O'Hara-Smith <steve at sohara.org>