Previously Tired Techie said:
I, too, am interested in the answer. I don't want my seldom-accessed
disks spinning all the time.
In addition, I spoke with the technical support folks at Buffalo
regarding their Buffalo Linkstation Network Storage Center. They have a
bug in their firmware such that the Linkstation sleep mode does not
work. No ETA on a fix. In addition, their built-in internal drive has
only a 2 MB buffer. The Seagate externals are 8 MB and I just saw a new
Maxtor with 16 MB.
Linksys NSLU2 can put itself to sleep, but the disks are still
spinning. Someone suggested putting the disks on an external timer,
like the kind you use for the lights in your house when you are away.
These all use a Linux file system. Should I be concerned about that ?
It is a very bad idea to just "unplug" the disks. ext2 as well
as the journalling alternatives are pretty reliable, so even a hard
power down will mostl only damage unwritten data. But given that
the flush-timeout on the kernel buffers is something like 5 minutes
you could loose quite a lot of data.
Still if you do this in a hardware/software combination and
unmunt or at least sync the drive before you do a hard timeout,
it should be o.k.. The set-up would be something like this:
Have a cron-job unmoun the disk and then have the external
time switch it off. Beware that external timers are often
not precison instruments. So you sould maybe add 30 minutes or
so of tolerance and check the external timer regularly. You
shuld also use ntp on the computer to ensure that its internal
timer is o.k.. And additionally you should use a journalling
filesystem (if you have ext2 yiou can convert to ext3 with
tune2fs -j <device>), in case you switch off accidentally
while the device is mounted. This will save you long disk-checks
on the next mount.
I had something similar on my old laptp: ext3 for the disk and
when traveling I run it until the accu gave out, since the
power reading gave me fantasy numbers (like 45 minutes
power left, when it read 3%). Never had serious problems
with that set-up.
I'm looking for a unit that has disk mirroring, as well as spinning
down the disks when not in use. Anything out there like that ?
A old PC or a small PC with e.g. a mini-itx-board and linux for
the functionality you want? Attached vie network? Probably cheapest.
I don't think you can really do with less, but if you buy it
pre-packaget, it is just going to cost more.
Arno
