On Tue, Jan 12, 2016 at 05:18:23PM +1100, Tennessee Leeuwenburg wrote:
> Based on my general new article reading, I thought everything above
> 6GB was using shingled storage which doesn't interest me so much. I'd
> be interested if you find out otherwise.
dunno about all drives 6TB and above, but definitely the Seagate Archive
drives (MSY have 6 & 8TB models, and IIRC Seagate recently-ish released
a 10TB model).
I've got a set of 4 x 4TB Seagate SSHDs, have no complaints about either
quality or performance. I've only got them because I had one (which i
was intending to use in my win7 steam games box) when I urgently needed
to upgrade my ZFS 'backup' pool, so i bought another 3 and set them up
as 2 mirrored pairs (for a total of 8TB).
I'm not using any ZIL or SSD L2ARC on the backup pool so having the 4GB
SSD cache (per drive) on it is probably beneficial. I haven't done
any performance testing (the urgency of the upgrade - the backup pool
had hit 90+% utilisation which is around where ZFS peformance goes to
absolute shit - precluded running bonnie++ before use) but they seem
reasonably fast to me, for magnetic spinning disks. they're certainly
no worse than non-SSHD disks and cost about the same - a little cheaper
than a Seagate NAS or WD Red.
$ zpool list -v backup
NAME SIZE ALLOC FREE EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT
backup 7.25T 2.54T 4.71T - 20% 35% 1.00x ONLINE -
mirror 3.62T 1.27T 2.35T - 20% 35%
sdb - - - - - -
sdi - - - - - -
mirror 3.62T 1.27T 2.35T - 20% 35%
sdd - - - - - -
sdc - - - - - -
$ list_disks | grep sd[bicd]
sdb ST4000DX001-1CE168_Z303PTHA
sdc ST4000DX001-1CE168_Z302ZSGB
sdd ST4000DX001-1CE168_Z303PVZ9
sdi ST4000DX001-1CE168_Z303PSH6
craig
ps: if anyone's wondering what 'list_disks' is, it's an alias of mine:
(line breaks and indentation added for readability)
alias list_disks='find /dev/disk/by-id/ -type l |
awk '\''/\/(s?ata|usb|scsi)/ && ! /-part[0-9]/'\'' |
while read disk ; do
echo $(basename $(readlink $disk)) $(basename $disk);
done |
sort'
can be saved as a script instead of an alias, just change the '\''
(which is how you quote single-quotes inside other single-quotes) to
plain '
i should probably simplify that one day and do the basename and readlink
stuff in awk rather than in a while read loop. may as well do it now:
alias list_disks2='find /dev/disk/by-id/ -type l |
awk '\''@load "filefuncs" ;
/\/(s?ata|usb|scsi)/ && ! /-part[0-9]/ {
stat($1,sd) ;
gsub(/^.*\//,"",sd["linkval"]) ;
gsub(/^.*\//,"",sd["name"]) ;
print sd["linkval"], sd["name"]
}'\'' |
sort'
this will only work with GNU awk, won't work in other awks because it
needs the filefuncs extension for stat(), and only gawk has extensions.
the downside is that it's not actually any simpler. certainly no easier
to read and understand. it is much more efficient because it avoids
executing external programs 'basename' and 'readlink' repeatedly, but
that's not really an issue on modern systems. my preference is to
optimise for readability (so i know WTF i was thinking in 6 months time)
rather than performance for shell/awk/etc scripts.
--
craig sanders <[email protected]>
BOFH excuse #247:
Due to Federal Budget problems we have been forced to cut back on the number of
users able to access the system at one time. (namely none allowed....)
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