I have a 2TB WD (My Passport Ultra) external HDD that has developed bad sectors, and I want to continue using it for non-essential/non-critical storage (I fortunately recovered all data that was on the drive, so data recovery is not the issue). The SMART info tells me that there are more bad sectors than spare ones.
My question is how to proceed with "ring-fencing" these bad sectors.
I understand from other posts here that just re-formatting the HDD, and letting the OS take care of marking the sectors as bad, so not re-using them, is not a good solution.
It was suggested elsewhere that I could partition the HDD, so the bad sectors are outside the partition. Is this really feasible, and if so, how to "tell" the partition software which part to exclude?
I have of course researched this topic a bit before posting, but as often is the case, quite some contradictory or vague information out there :
- Re: bad sectors : some claim that once you start having bad sectors, these will "propagate" (e.g. because a bad sector often (?) is related to something physically wrong on the platter surface, hence every time the head moves over that area, the head "jumps" a bit and creates additional bad sectors); others claim that bad sectors are just "normal" for HDDs, so either the HDD itself marks them and uses a spare sector, or you have to do this manually, e.g. with chkdsk, but in any case you can still reliably use the HDD;
- Re: continue using the disk : some say the disk could die within seconds/minutes, others says you can still use the disk for years once the bad sectors are not used anymore;
- Re: bad sectors and spares : the info seems quite inconsistent and inconclusive about when a HDD is actually not fit for use anymore. It seems that as long as the HDD itself (the firmware/controller?) manages the "replacement" of bad sectors with spare ones all is fine, and in the SMART data you can see which % of the spares have been used, and if below a threshold, all is "green"; but once the user is confronted with a bad sector (presumably because the sector became bad after data was written to it, and you get CRC errors?), it seems that the consensus is to go into semi-panic mode, clone/recover what can be recovered, and throw the HDD in the fire. I am just making up the numbers, but if there are a few hundred (thousand?) of spare sectors, and the first few hundred of bad sectors are considered "normal", why the next few hundred of bad sectors suddenly are such a drama ? There are millions of sectors on a HDD, so is this rational behavior, statistically speaking ?
Similar questions on SU:
- Partition for bad sectors : gives interesting insights, but question is not answered in detail;
- Formatting and HDD controllers : technical and insightful, but focus on formatting only
- Scanning for bad sectors : no info about partitioning.
- Bad sectors and repartitioning : the answer focuses on bad vs spare sectors, but not on what to do
- Reformatting and bad sectors : discusses formatting and firmware and spare sectors, and how bad sectors are found and marked.
- Bad sectors on HDD : outlines problem and diagnostic, but not really how to solve with a partition
- Fixing bad sectors : the last answer comes close, but gives very little information.
So lots of information, but nowhere a clear answer on (i) whether it is actually possible to create a partition to omit all bad sectors (and so that the head does never touches that bad area anymore), (ii) whether this will mitigate the risk that more bad sectors will appear, and (iii) some guidance how to accomplish this with a good/quality partitioning software (e.g. how much buffer to leave around the bad sectors) (there are some specific tools out there to create partitions that omit bad sectors, but they do not seem very reliable to me, but again, maybe I am just ignorant).
EDIT (Nov 2018)
Other SU discussion about similar topic :How can I partition out damaged sectors on a HDD?
