[Info-vax] Reclaim disk space for a 3PAR Storage Box

[Chris Scheers]

Bill Gunshannon wrote:
> On 8/31/21 1:42 PM, Arne Vajhøj wrote:
>> On 8/30/2021 10:03 PM, Dave Froble wrote:
>>> On 8/30/2021 1:44 PM, Simon Clubley wrote:
>>>> On 2021-08-30, Stephen Hoffman <seaohveh at hoffmanlabs.invalid> wrote:
>>>>> A whole lot has changed with storage and storage I/O since HDDs 
>>>>> reigned
>>>>> supreme. 12 TB drives, and 4 TB SSDs are now commonplace, among other
>>>>> differences.
>>>>
>>>> SSDs make me nervous because when they fail, they tend to fail hard
>>>> and sudden without any warning.
>>>
>>> Never seen a total head crash on a HDD?  Ok, neither have I, but I 
>>> have seen HDDs fail, and once they start, you cannot count on getting 
>>> accurate data off them.
>>>
>>> Oh, and welcome to the new world of cheap and semi-reliable PC junk 
>>> hardware ....
>>>
>>>> Hardware RAID or software volume shadowing would normally take care
>>>> of that but there have been enough cases in recent years where a
>>>> complete set of SSD devices all fail at the same time due to firmware
>>>> bugs to make me nervous about using them.
>>>
>>> See above about cheap and semi-reliable PC junk hardware ....
>>
>> There are usually some correlation between price and quality.
>>
>> I have no doubt that:
>>
>> MTBF(enterprise,2021) > MTBF(consumer,2021)
>> MTBF(enterprise,1986) > MTBF(consumer,1986)
>>
>> but at least for disk then:
>>
>> MTBF(consumer,2021) > MTBF(enterprise,1986)
>>
>> Modern disks are actually pretty reliable.
>>
>> VAX disks were not always reliable. I remember a 8650
>> with RA81's and RA82's - DEC field service replaced disks
>> several times per year (especially the RA81's).
>>
> 
> Interesting.  I had about two dozen RA80's and 81's  That were
> old and used when I got them.  Ran them for years on VAX and PDP-11's.
> Never had a failure and passed them all on when I had to get rid of
> those systems.  Would not be surprised to find they are still running.

The early RA81s had a problem where the heads would "unglue" from the 
actuator and totally trash the disk.

DEC actively hunted out and replaced those original drives.  The 
replacement RA81s were good and ran forever.

I never really had a problem with RA80s or RA82s.

-- 
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Chris Scheers, Applied Synergy, Inc.

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