PC-3000 for HDD. How to hide defects on Toshiba HDD. FAQ.
Where can I hide defects?
What is the difference between hiding defects into P-list or G-list ?
Principal difference is that when you hide defect/group of defects into P-List defect disappear
from translation (so capacity will less), in case of G-list defect replaced with sector from reserved
area. Also you can’t hide tracks or group of tracks in G-list.
Also there will be delay in read/writing operations at replaced in G-list sectors – due to the
fact that to read these sectors, the head must be moved to the reserve area and back, which
takes quite a while.
What is the maximum amount of defects I can hide?
Typically maximum length of G-list – 1024 entries (or 1912 sectors) and it depens on size
of reserved area. On new foDefects can be only sectoral (so single LBA or LBA chain).
Maximum amount of chains for P-list depends on family. On old HDDs – 1022, on newer
– 4094, on latest – 16382. You can check the exact value for a specific disk from “Zones
and heads inactivation” startup log (“P-List capacity” parameter). Defects can be not only sectoral,
you can hide single LBA, group of LBA till 24 sectors per track, whole tracks or group of tracks.
How to completely disable dead head?
You need to use “Zone and heads inactivation” feature. Please note that such ability is available
only for version greater than 6.0.x.
If you want to revert to a previous state before this procedure you need to write back CP
56 and DD which was automatically saved in ZoneBackup catalog of HDD profile.
How to hide zones?
Almost same way like disabling
heads – you need to open microzones editor (Tools -> Utility extensions -> Zones
and heads inactivation or Ctrl+Alt+3), select zones to hide and press “Apply table” icon.
Why hiding defect doesn’t work?
It’s impossible to disable head if number of microzones per head < than P-list capacity.
For example, the MK3263GSX model has 1022 entries in the P-List, but the number
of microzones per each Head is 2196. Therefore, it is impossible to hide a dead head completely.
You can easily estimate possibility of hiding head: check number of zones by head then
check P-list capacity. If P-list is smaller – it’s impossible.
For the 32GSX and 37GSX families, PBAs can be hidden only up to a certain limited
number. For example, at MK6037GSX you can hide 17849743 PBA, but 17849744
and more can’t be hidden. Probably, this applies only to some f/w.
There are many families that don’t allow to hide PBA=0, probably only some f/w, it
has to be checked experimentally. That’s why at such HDDs you won’t be able to
completely hide the Head 0. To be more precise, it will be possible to hide all the
PBAs related to Head 0, except PBA=0. If you faced with this situation, I recommend
to try hide PBA=0 in G-list.
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