External drive attached to a DVR

I've been having some problems recently with recording programs to my
DVR. It's got a 500GB external eSATA/USB drive which I put together from
parts. It had been running perfectly for over a year, and started acting
up just a few weeks ago. So I took the external storage and attached it
to my laptop to check its SMART health. I did that about three days ago,
and it came back clean, no errors at all. So I put it back on my DVR and
ran it some more. It still wasn't recording programs. I noticed that the
drive was making some noises occasionally, like it was getting stuck and
then freeing itself. So I took the drive out again and reattached to the
laptop, and all of a sudden SMART was showing over 80 relocated sectors!
In the span of 1 or 2 days, it had gotten a bunch of bad sectors?

The DVR has some kind of proprietary filesystem format. But I'm
surprised it would get flustered by bad sectors, shouldn't the drive
take care of that? How long does it take the drive to reallocate the
reserve sectors when it discovers bad ones?

Yousuf Khan

Yousuf Khan wrote:
I've been having some problems recently with recording programs to my
DVR. It's got a 500GB external eSATA/USB drive which I put together from
parts. It had been running perfectly for over a year, and started acting
up just a few weeks ago. So I took the external storage and attached it
to my laptop to check its SMART health. I did that about three days ago,
and it came back clean, no errors at all. So I put it back on my DVR and
ran it some more. It still wasn't recording programs. I noticed that the
drive was making some noises occasionally, like it was getting stuck and
then freeing itself. So I took the drive out again and reattached to the
laptop, and all of a sudden SMART was showing over 80 relocated sectors!
In the span of 1 or 2 days, it had gotten a bunch of bad sectors?

The DVR has some kind of proprietary filesystem format. But I'm
surprised it would get flustered by bad sectors, shouldn't the drive
take care of that? How long does it take the drive to reallocate the
reserve sectors when it discovers bad ones?

If the drive can recover the data in a sector read with errors, it
will allocated immediately. The recovery process may take pretty
long, depending on the drive. I think 30 sec are a real
possibility.

If the drive cannot recover the data, then the read will return
in an error and the sector will show up as "pending" in the SMART
data. On the next read, the drive will again try to recover
the data. If the sector gets written, and hence the drive has the
data, it will run a short r/w test of the sector and unless it
passes, reallocation will happen immediately.

So, it is quite possible that the PVR gets flustered by a)
failed reads and b) very long read times. The other oprion is
filesystem corruption or some other software issue, that
a PVR can suffer from as well. No idea how to fix that except
to blank the drive.

Arno
--
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email:
GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

Yousuf Khan wrote:
I've been having some problems recently with recording programs to my
DVR. It's got a 500GB external eSATA/USB drive which I put together
from parts. It had been running perfectly for over a year, and
started acting up just a few weeks ago. So I took the external
storage and attached it to my laptop to check its SMART health. I did
that about three days ago, and it came back clean, no errors at all.
So I put it back on my DVR and ran it some more. It still wasn't
recording programs. I noticed that the drive was making some noises
occasionally, like it was getting stuck and then freeing itself. So I
took the drive out again and reattached to the laptop, and all of a
sudden SMART was showing over 80 relocated sectors! In the span of 1 or 2 days, it had gotten a bunch of bad sectors?

The DVR has some kind of proprietary filesystem format. But I'm surprised it would get flustered by bad sectors,
shouldn't the drive take care of that?

Yes, but should and does are two quite different things.

How long does it take the drive to reallocate the
reserve sectors when it discovers bad ones?

It only does that on a write, so you can recover the data manually if you want to.

Presumably at least some of the bads were in the directory structure.

On 2/5/2011 12:15 PM, Arno wrote:
If the drive can recover the data in a sector read with errors, it
will allocated immediately. The recovery process may take pretty
long, depending on the drive. I think 30 sec are a real
possibility.

If the drive cannot recover the data, then the read will return
in an error and the sector will show up as "pending" in the SMART
data. On the next read, the drive will again try to recover
the data. If the sector gets written, and hence the drive has the
data, it will run a short r/w test of the sector and unless it
passes, reallocation will happen immediately.

Well, it looks like then, that's exactly what might have happened as
there is one pending sector count in the SMART:

No. Attribute Thre.. Value Worst Data Status Flags
1 Raw Read Error Rate 16 100 100 0 OK Error-Rate, Statistical, Critical
2 Throughput Performance 50 148 148 264 OK Performance, Critical
3 Spin Up Time 24 106 106 42926741 OK Performance, Statistical, Critical
4 Start/Stop Count 0 100 100 236 OK (Always passing) Event Count, Statistical
5 Reallocated Sectors Co.. 5 100 100 87 OK Self Preserving, Event Count, Statistical, Critical
7 Seek Error Rate 67 100 100 0 OK Error-Rate, Statistical, Critical
8 Seek Time Performance 20 134 134 32 OK Performance, Critical
9 Power-On Time Count 0 98 98 18992 OK (Always passing) Event Count, Statistical
10 Spin Retry Count 60 100 100 0 OK Event Count, Statistical, Critical
12 Drive Power Cycle Count 0 100 100 114 OK (Always passing) Self Preserving, Event Count, Statistical
192 Power off Retract Cycle 50 100 100 261 OK Self Preserving, Event Count, Statistical
193 Load/Unload Cycle Count 50 100 100 261 OK Event Count, Statistical
194 HDD Temperature 0 229 229 56; 18; 24 OK (Always passing) Statistical
196 Reallocation Event Count 0 100 100 96 OK (Always passing) Self Preserving, Event Count, Statistical
197 Current Pending Sector.. 0 100 100 1 OK (Always passing) Self Preserving, Statistical
198 Off-Line Uncorrectable.. 0 100 100 0 OK (Always passing) Error-Rate
199 Ultra ATA CRC Error Co.. 0 200 253 1 OK (Always passing) Error-Rate, Statistical

I can't believe this, my DVR has eaten another hard disk! This time it
was a 1TB Seagate, rather than a 500GB Hitachi. I bought the Seagate
just 12 days ago to replace the Hitachi. What the hell is this DVR doing
that's so hard on hard drives? The new drive all of a sudden has 312 bad
sectors!

Yousuf Khan

On 2/5/2011 11:07 AM, Yousuf Khan wrote:
I've been having some problems recently with recording programs to my
DVR. It's got a 500GB external eSATA/USB drive which I put together from
parts. It had been running perfectly for over a year, and started acting
up just a few weeks ago. So I took the external storage and attached it
to my laptop to check its SMART health. I did that about three days ago,
and it came back clean, no errors at all. So I put it back on my DVR and
ran it some more. It still wasn't recording programs. I noticed that the
drive was making some noises occasionally, like it was getting stuck and
then freeing itself. So I took the drive out again and reattached to the
laptop, and all of a sudden SMART was showing over 80 relocated sectors!
In the span of 1 or 2 days, it had gotten a bunch of bad sectors?

The DVR has some kind of proprietary filesystem format. But I'm
surprised it would get flustered by bad sectors, shouldn't the drive
take care of that? How long does it take the drive to reallocate the
reserve sectors when it discovers bad ones?

Yousuf Khan

Insufficient mains isolation?

Arno


Yousuf Khan wrote:
I can't believe this, my DVR has eaten another hard disk! This time it
was a 1TB Seagate, rather than a 500GB Hitachi. I bought the Seagate
just 12 days ago to replace the Hitachi. What the hell is this DVR doing
that's so hard on hard drives? The new drive all of a sudden has 312 bad
sectors!

Yousuf Khan

On 2/5/2011 11:07 AM, Yousuf Khan wrote:
I've been having some problems recently with recording programs to my
DVR. It's got a 500GB external eSATA/USB drive which I put together from
parts. It had been running perfectly for over a year, and started acting
up just a few weeks ago. So I took the external storage and attached it
to my laptop to check its SMART health. I did that about three days ago,
and it came back clean, no errors at all. So I put it back on my DVR and
ran it some more. It still wasn't recording programs. I noticed that the
drive was making some noises occasionally, like it was getting stuck and
then freeing itself. So I took the drive out again and reattached to the
laptop, and all of a sudden SMART was showing over 80 relocated sectors!
In the span of 1 or 2 days, it had gotten a bunch of bad sectors?

The DVR has some kind of proprietary filesystem format. But I'm
surprised it would get flustered by bad sectors, shouldn't the drive
take care of that? How long does it take the drive to reallocate the
reserve sectors when it discovers bad ones?

Yousuf Khan


--
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email:
GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

Yousuf Khan wrote:

I can't believe this, my DVR has eaten another hard disk! This time it
was a 1TB Seagate, rather than a 500GB Hitachi. I bought the Seagate
just 12 days ago to replace the Hitachi. What the hell is this DVR doing that's so hard on hard drives? The new drive
all of a sudden has 312 bad sectors!

I was going to suggest inadequate cooling, but surely its the winter there ?

You havent got it in an unusually warmed room or location have you ?

If its not that, most likely its the power supply thats killing the
drives or just plain very bad luck. The last in very unlikely tho.


Yousuf Khan wrote

I've been having some problems recently with recording programs to my
DVR. It's got a 500GB external eSATA/USB drive which I put together
from parts. It had been running perfectly for over a year, and
started acting up just a few weeks ago. So I took the external
storage and attached it to my laptop to check its SMART health. I
did that about three days ago, and it came back clean, no errors at
all. So I put it back on my DVR and ran it some more. It still
wasn't recording programs. I noticed that the drive was making some
noises occasionally, like it was getting stuck and then freeing
itself. So I took the drive out again and reattached to the laptop,
and all of a sudden SMART was showing over 80 relocated sectors! In
the span of 1 or 2 days, it had gotten a bunch of bad sectors?

The DVR has some kind of proprietary filesystem format. But I'm
surprised it would get flustered by bad sectors, shouldn't the drive
take care of that? How long does it take the drive to reallocate the
reserve sectors when it discovers bad ones?

On 11-02-20 03:49 PM, Rod Speed wrote:
Yousuf Khan wrote:

I can't believe this, my DVR has eaten another hard disk! This time it
was a 1TB Seagate, rather than a 500GB Hitachi. I bought the Seagate
just 12 days ago to replace the Hitachi. What the hell is this DVR doing that's so hard on hard drives? The new drive
all of a sudden has 312 bad sectors!

I was going to suggest inadequate cooling, but surely its the winter there ?

You havent got it in an unusually warmed room or location have you ?

No, it's actually quite out in the open, with lots of visible space in
between for ventilation. I also have long ago replaced its enclosure
with a good quality Vantec aluminum one. When I feel the outside of the
case, it doesn't even feel all that warm either.

If its not that, most likely its the power supply thats killing the
drives or just plain very bad luck. The last in very unlikely tho.

It's too bad that the DVR doesn't support SMART monitoring. The only way
I can monitor its SMART status is by unplugging it from the DVR and
plugging to my laptop. When I do that, the temperature doesn't show as
too high either (less than 30 C), although mind you there is a brief
period of time between moving from DVR to laptop where it's got some
time to cool, but I don't think it's all that much time.

However, when I ran the SMART self-test on it, the number of bad sectors
kept going up. It initially started out at 276 bad sectors, then after a
short self-test, it went upto 312 bad sectors. Then with a long
self-test it went upto 508 bad sectors and counting (I stopped the test).

One advantage of having the drive fail so quickly is that there is
absolutely no doubt its warranty status. The store just simply did a
quick check over and then exchanged it. But all of the programs I had
recorded on it are now gone.

Yousuf Khan

On 11-02-20 10:17 AM, Arno wrote:
Insufficient mains isolation?

Arno

You mean lack of power-wise, or noisy power-wise? It was connected to a
surge suppressor power bar.

Yousuf Khan

Yousuf Khan wrote
Rod Speed wrote
Yousuf Khan wrote

I can't believe this, my DVR has eaten another hard disk! This time
it was a 1TB Seagate, rather than a 500GB Hitachi. I bought the Seagate just 12 days ago to replace the Hitachi.
What the hell is this DVR doing that's so hard on hard drives? The new drive all of a sudden has 312 bad sectors!

I was going to suggest inadequate cooling, but surely its the winter there ?

You havent got it in an unusually warmed room or location have you ?

No, it's actually quite out in the open, with lots of visible space in
between for ventilation. I also have long ago replaced its enclosure
with a good quality Vantec aluminum one. When I feel the outside of the case, it doesn't even feel all that warm
either.

OK, then most likely its power supply is dying.

If its not that, most likely its the power supply thats killing the
drives or just plain very bad luck. The last in very unlikely tho.

It's too bad that the DVR doesn't support SMART monitoring. The only
way I can monitor its SMART status is by unplugging it from the DVR
and plugging to my laptop. When I do that, the temperature doesn't
show as too high either (less than 30 C), although mind you there is
a brief period of time between moving from DVR to laptop where it's
got some time to cool, but I don't think it's all that much time.

Yeah, the temperature measurement should be close enough.

However, when I ran the SMART self-test on it, the number of bad
sectors kept going up. It initially started out at 276 bad sectors, then after a short self-test, it went upto 312 bad
sectors. Then with a long self-test it went upto 508 bad sectors and counting (I stopped the test).

Almost certainly the power supply is failing.

One advantage of having the drive fail so quickly is that there is absolutely no doubt its warranty status. The store
just simply did a quick check over and then exchanged it.

They likely wont the next time it fails tho. They'll decide that the housing is killing the drives.

But all of the programs I had recorded on it are now gone.

Yeah, its a real pain with a PVR. I've already got something
like 10TB of stuff I havent gotten around to watching, and
aint about to duplicate that to protect against drive failure.

Its getting past a joke anyway, I found I watched **** all off
the backups for the PVR during our summer quiet season
just finished and have started to delete stuff on those drives
that I'll never get around to watching, mostly fiction but also
some classes of doco, particularly the nature stuff.

That 10TB is a number of physical drives so I wouldnt
lose a very big percentage on a single drive failure.