Backups [was Re: Is tape dead?]

Sean Caron scaron at umich.edu
Fri Sep 25 17:55:41 CDT 2015


Er, sorry, HDAs, not HBAs :O

Best,

Sean

On Fri, Sep 25, 2015 at 6:55 PM, Sean Caron <scaron at umich.edu> wrote:

> The WDC REs are not bad drives at all but IMO Hitachi Ultrastar is the
> best line going right now. I have been working with them for some time from
> 0.5T through 3T under very high duty cycle and they are fairly bulletproof.
> The REs will do the work, but I have seen higher failure rates on them
> right out of the box and higher failure rates on them in the longer term
> (~3 years) versus the Hitachi. I am hesitant to trust Seagate for large
> scale enterprise use though I think they are fine to use at home, in
> lighter duty cycle applications or in USB enclosures, etc.
>
> The distinction you point out is very important particularly when
> selecting drives to use in constructing a RAID; it's critical to avoid
> those drives that attempt to spin down or sleep when idle; this confuses
> the heck out of RAID and will cause the admin (we, the builder) no end of
> misery... usually it's easy to identify these drives because they are
> marketed as "Green" or "energy saver" but for some of the midrange product
> lines ... "prosumer" ... sometimes you have to dig a little to get to the
> facts. I think these Green drives are the worst thing on the market since
> the old Quantum Bigfoot; I wouldn't recommend them to anyone.
>
> I suggest starting with the keyword "enterprise SATA" and going from there
> ... these drives are certified for array use 24/7 and ship without any
> "power saving" nonsense straight from the OEM ... the premium over a normal
> consumer SATA disk is not really too awful. These generally use identical
> or very closely related HBAs to the premium SAS disks but just with
> different SATA-only formatter board. No real need to go SAS unless you
> require multipath.
>
> Best,
>
> Sean
>
>
> On Fri, Sep 25, 2015 at 4:56 PM, Alexander Schreiber <als at thangorodrim.ch>
> wrote:
>
>> On Thu, Sep 24, 2015 at 11:33:59PM -0700, Chuck Guzis wrote:
>> > On 09/24/2015 04:30 PM, Alexander Schreiber wrote:
>> >
>> > >IMHO, you want to buy at one generation below the current max
>> > >capacity on the assumption that they ironed out the bugs on that
>> > >one.
>> >
>> > So, if you were to move up from the 500GB SATA drives to the "next
>> > generation", which would you choose?
>>
>> My last set of drives where WD Red 2TB drives. They are designed for NAS,
>> so can deal with 24/7 operation. One word of warning on those: by default
>> they spin down on idle (and spin up again on access). In a typical light
>> loaded environment, that is likely to run up the load cycles sky high
>> in a hurry. So I recommended completely disabling that (note: after
>> changing this setting, the drives need a power cycle).
>>
>> Older ones: I'm quite fond of WD RE series drives, a bit more expensive
>> but from my experience very reliable.
>>
>> Kind regards,
>>            Alex.
>> --
>> "Opportunity is missed by most people because it is dressed in overalls
>> and
>>  looks like work."                                      -- Thomas A.
>> Edison
>>
>
>


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