[Noisebridge-discuss] [RUG] Data integrity, SMART and SSD's

[John Magolske]

I'm looking for strategies around maintaining data integrity. The
primary machine in question where data is gathered, manipulated &
stored is a laptop with an SSD hard-drive (actually a CF card + CF to
IDE adapter). This is rsync'd to backups on external USB hard-drives.

At the last RUG (Rsync Users Group) meeting there was mention of
the usefulness of SMART (Self-Monitoring, Analysis and Reporting
Technology) systems, which are built into many (all?) ATA, IDE and
SCSI-3 hard drives.

>From SMARTCTL(8):

    The purpose of SMART is to monitor the reliability of the hard
    drive and predict drive failures, and to carry out different
    types of drive self-tests.

Issuing `smartctl -a` to my Transcend & SanDisk CF cards gets:

    SMART support is: Ambiguous - ATA IDENTIFY DEVICE words 85-87
    don't show if SMART is enabled.

    SMART support is: Unavailable - Packet Interface Devices
    [this device: Write-once (optical disk)] don't support ATA SMART

I also understand that SMART doesn't work with USB hard drives. So it
appears that nowhere would the benefits of SMART be present in this
particular situation. Which leaves me me wondering...

How helpful is SMART in maintaining data integrity?

Is there a way to gain the benefits of SMART in the above scenario?
I'm thinking maybe by doing the rsync backups to a hard-drive built
into another computer... Or maybe there's an external hard-drive with
a little computer built in that allows SMART to function?

I'm a bit concerned about keeping the primary repository of a
collection of data on a CF card. If some cells fail on read (is that
possible? or do they only fail on write?) and that is rsync'd to an
external hard-drive target, what are the chances those errors will
be propagated without being detected? In general, what would be some
recommended tools & strategies to ensure ongoing data integrity?

TIA for any suggestions,

John


-- 
John Magolske
http://B79.net/contact