Enabling/Disabling write-caching on the system drive

Has anybody had any first hand experience with this? I've read the pro's
and con's about enabling/disabling hard disk write caching, but it would be
good to actually hear about some real cases, and not just the theoretical
concerns, especially for something as fundamental as the main system drive.

Leave it on for anything permanent, e.g. internal hard disks. Turn it off
for anything removable. That way you can disconnect it without (supposedly)
risking data corruption with info hasn't been written yet.

"Bill in Co" wrote in message
m...
Has anybody had any first hand experience with this? I've read the pro's
and con's about enabling/disabling hard disk write caching, but it would
be good to actually hear about some real cases, and not just the
theoretical concerns, especially for something as fundamental as the main
system drive.

However - there is that small risk with fixed disks (your hard-drives),
with write-caching turned on, that data would be lost if there was a sudden
power failure....

But the benefits , I think, do outweigh that small risk.
==

Cheers, Tim Meddick, Peckham, London. :-)




"pjp" wrote in message
...
Leave it on for anything permanent, e.g. internal hard disks. Turn it off
for anything removable. That way you can disconnect it without
(supposedly) risking data corruption with info hasn't been written yet.

"Bill in Co" wrote in message
m...
Has anybody had any first hand experience with this? I've read the
pro's and con's about enabling/disabling hard disk write caching, but it
would be good to actually hear about some real cases, and not just the
theoretical concerns, especially for something as fundamental as the
main system drive.

Although true, there is a slight risk if there's a power failure but I kinda
see that as makes no diff if the power goes out during the cached write
committing to hard disk or it goes out without it active. Results in same
"discontinuity" of data as the write itself didn't finish completely.

"Tim Meddick" wrote in message
...
However - there is that small risk with fixed disks (your hard-drives),
with write-caching turned on, that data would be lost if there was a
sudden power failure....

But the benefits , I think, do outweigh that small risk.
==

Cheers, Tim Meddick, Peckham, London. :-)




"pjp" wrote in message
...
Leave it on for anything permanent, e.g. internal hard disks. Turn it off
for anything removable. That way you can disconnect it without
(supposedly) risking data corruption with info hasn't been written yet.

"Bill in Co" wrote in message
m...
Has anybody had any first hand experience with this? I've read the
pro's and con's about enabling/disabling hard disk write caching, but it
would be good to actually hear about some real cases, and not just the
theoretical concerns, especially for something as fundamental as the
main system drive.

That's the point I was driving at. I was interested in hearing any "war
stories" on that from a user who had actually experienced such problems in
leaving it enabled and losing data.

Up to this point, I've left the disk write caching DISABLED on my system
drive, just to prevent any such occurences, but it may be overkill on my
part to do so.

I do know that disk write caching can help speed some things up a bit (at
least in some cases) if you enable it, however. I've noticed a difference
in some cases (plus there is less instantaneous disk activity, since it
writes it from a full cache, instead of byte by byte, so to speak)

Tim Meddick wrote:
However - there is that small risk with fixed disks (your hard-drives),
with write-caching turned on, that data would be lost if there was a
sudden
power failure....

But the benefits , I think, do outweigh that small risk.
==

Cheers, Tim Meddick, Peckham, London. :-)




"pjp" wrote in message
...
Leave it on for anything permanent, e.g. internal hard disks. Turn it off
for anything removable. That way you can disconnect it without
(supposedly) risking data corruption with info hasn't been written yet.

"Bill in Co" wrote in message
m...
Has anybody had any first hand experience with this? I've read the
pro's and con's about enabling/disabling hard disk write caching, but it
would be good to actually hear about some real cases, and not just the
theoretical concerns, especially for something as fundamental as the
main system drive.

I thought the point I was making/asking was it seems irrelevant when the
write actually happens as there's no way to avoid the possibility of power
failure at that time. Given that, might as well go with performance mode so
to speak.

As I live in very rural area, I've had many power failures. Usually only the
file I might have been editing gets corrupted. I've had as many hardware
issues because of it. Last one lost a video card and hard disk started
becoming suspect also. Laptops kinda nice for avoiding that kinda problem as
they seem to switch fast enough to battery.

"Bill in Co" wrote in message
m...
That's the point I was driving at. I was interested in hearing any "war
stories" on that from a user who had actually experienced such problems in
leaving it enabled and losing data.

Up to this point, I've left the disk write caching DISABLED on my system
drive, just to prevent any such occurences, but it may be overkill on my
part to do so.

I do know that disk write caching can help speed some things up a bit (at
least in some cases) if you enable it, however. I've noticed a difference
in some cases (plus there is less instantaneous disk activity, since it
writes it from a full cache, instead of byte by byte, so to speak)

Tim Meddick wrote:
However - there is that small risk with fixed disks (your hard-drives),
with write-caching turned on, that data would be lost if there was a
sudden
power failure....

But the benefits , I think, do outweigh that small risk.
==

Cheers, Tim Meddick, Peckham, London. :-)




"pjp" wrote in message
...
Leave it on for anything permanent, e.g. internal hard disks. Turn it
off
for anything removable. That way you can disconnect it without
(supposedly) risking data corruption with info hasn't been written yet.

"Bill in Co" wrote in message
m...
Has anybody had any first hand experience with this? I've read the
pro's and con's about enabling/disabling hard disk write caching, but
it
would be good to actually hear about some real cases, and not just the
theoretical concerns, especially for something as fundamental as the
main system drive.

pjp wrote:
I thought the point I was making/asking was it seems irrelevant when the
write actually happens as there's no way to avoid the possibility of power
failure at that time. Given that, might as well go with performance mode
so
to speak.

Yeah, you may have a point. Either way you might lose data, so that the
file being written becomes corrupted. So maybe the only time turning off
the write disk caching is of any practical value is for the removeable
drives.

As I live in very rural area, I've had many power failures. Usually only
the
file I might have been editing gets corrupted. I've had as many hardware
issues because of it. Last one lost a video card and hard disk started
becoming suspect also.

Wow. Now THAT is pretty bad. :-(

Laptops kinda nice for avoiding that kinda problem as
they seem to switch fast enough to battery.

It almost sounds like you should get one of the UPS supplies (universal
power supply, with a battery backup, as I recall).

From what you've said above, I think I'd probably bite the bullet and spend
the bucks and do it in your case! I don't think they are all that
expensive, either.

"Bill in Co" wrote in message
m...
That's the point I was driving at. I was interested in hearing any
"war
stories" on that from a user who had actually experienced such problems
in
leaving it enabled and losing data.

Up to this point, I've left the disk write caching DISABLED on my system
drive, just to prevent any such occurences, but it may be overkill on my
part to do so.

I do know that disk write caching can help speed some things up a bit (at
least in some cases) if you enable it, however. I've noticed a
difference
in some cases (plus there is less instantaneous disk activity, since it
writes it from a full cache, instead of byte by byte, so to speak)

Tim Meddick wrote:
However - there is that small risk with fixed disks (your hard-drives),
with write-caching turned on, that data would be lost if there was a
sudden
power failure....

But the benefits , I think, do outweigh that small risk.
==

Cheers, Tim Meddick, Peckham, London. :-)




"pjp" wrote in message
...
Leave it on for anything permanent, e.g. internal hard disks. Turn it
off
for anything removable. That way you can disconnect it without
(supposedly) risking data corruption with info hasn't been written yet.

"Bill in Co" wrote in message
m...
Has anybody had any first hand experience with this? I've read the
pro's and con's about enabling/disabling hard disk write caching, but
it
would be good to actually hear about some real cases, and not just the
theoretical concerns, especially for something as fundamental as the
main system drive.

"pjp" wrote in message
...
I thought the point I was making/asking was it seems irrelevant when the
write actually happens as there's no way to avoid the possibility of power
failure at that time. Given that, might as well go with performance mode so
to speak.

As I live in very rural area, I've had many power failures. Usually only
the file I might have been editing gets corrupted. I've had as many
hardware issues because of it. Last one lost a video card and hard disk
started becoming suspect also. Laptops kinda nice for avoiding that kinda
problem as
they seem to switch fast enough to battery.

Don't you have an uninterruptible power supply (UPS)? It's enitre purpose
is power failures and surge protection. It would (almost) eliminate the
possibility of losing hardware or data.

MB

"MerseyBeat" wrote in message
...
"pjp" wrote in message
...
I thought the point I was making/asking was it seems irrelevant when the
write actually happens as there's no way to avoid the possibility of power
failure at that time. Given that, might as well go with performance mode
so to speak.

As I live in very rural area, I've had many power failures. Usually only
the file I might have been editing gets corrupted. I've had as many
hardware issues because of it. Last one lost a video card and hard disk
started becoming suspect also. Laptops kinda nice for avoiding that kinda
problem as
they seem to switch fast enough to battery.

Don't you have an uninterruptible power supply (UPS)? It's enitre purpose
is power failures and surge protection. It would (almost) eliminate the
possibility of losing hardware or data.

Sir, where some of us live, the possibility of a UPS going wrong is higher
than any interruption of mains electricity! Though what can or may happen in
a few years down the line is anybody's guess.
--
choro
*****

MB

"choro" wrote in message
...
"MerseyBeat" wrote in message
...
"pjp" wrote in message
...
I thought the point I was making/asking was it seems irrelevant when the
write actually happens as there's no way to avoid the possibility of
power failure at that time. Given that, might as well go with performance
mode so to speak.

As I live in very rural area, I've had many power failures. Usually only
the file I might have been editing gets corrupted. I've had as many
hardware issues because of it. Last one lost a video card and hard disk
started becoming suspect also. Laptops kinda nice for avoiding that
kinda problem as
they seem to switch fast enough to battery.

Don't you have an uninterruptible power supply (UPS)? It's enitre
purpose is power failures and surge protection. It would (almost)
eliminate the possibility of losing hardware or data.

Sir, where some of us live, the possibility of a UPS going wrong is higher
than any interruption of mains electricity! Though what can or may happen
in a few years down the line is anybody's guess.
--
choro
*****

Choro,

Firstly, I was responding directly to pjp and not generalizing. If I quote
pjp, they specifically wrote "As I live in very rural area, I've had many
power failures". With that in mind, if power failures are that frequent, I
would highly advise them to get a UPS.

Secondly, I really can't imagine that a UPS would fail any more frequently
than the likelihood of the main electicity failing. If a UPS saves any
piece of expensive hardware or some very important data, then, it would seem
to me, to be worth it's weight in gold. Besides, UPS's don't just protect
against failing electicity, most are also surge protectors which can protect
against lighting stikes. It only takes one lighting strike to fry your
whole computer, hard disk and all. Then I bet you'd wish you had a UPS.
Don't bother to argue the point that you can buy a surge protector alone for
cheaper than a UPS. That's a separate argument.

MB

"MerseyBeat" wrote in message
...
"choro" wrote in message
...
"MerseyBeat" wrote in message
...
"pjp" wrote in message
...
I thought the point I was making/asking was it seems irrelevant when the
write actually happens as there's no way to avoid the possibility of
power failure at that time. Given that, might as well go with
performance mode so to speak.

As I live in very rural area, I've had many power failures. Usually
only the file I might have been editing gets corrupted. I've had as
many hardware issues because of it. Last one lost a video card and hard
disk started becoming suspect also. Laptops kinda nice for avoiding
that kinda problem as
they seem to switch fast enough to battery.

Don't you have an uninterruptible power supply (UPS)? It's enitre
purpose is power failures and surge protection. It would (almost)
eliminate the possibility of losing hardware or data.

Sir, where some of us live, the possibility of a UPS going wrong is
higher than any interruption of mains electricity! Though what can or may
happen in a few years down the line is anybody's guess.
--
choro
*****

Choro,

Firstly, I was responding directly to pjp and not generalizing. If I
quote pjp, they specifically wrote "As I live in very rural area, I've had
many power failures". With that in mind, if power failures are that
frequent, I would highly advise them to get a UPS.

Secondly, I really can't imagine that a UPS would fail any more frequently
than the likelihood of the main electicity failing. If a UPS saves any
piece of expensive hardware or some very important data, then, it would
seem to me, to be worth it's weight in gold. Besides, UPS's don't just
protect against failing electicity, most are also surge protectors which
can protect against lighting stikes. It only takes one lighting strike to
fry your whole computer, hard disk and all. Then I bet you'd wish you had
a UPS. Don't bother to argue the point that you can buy a surge protector
alone for cheaper than a UPS. That's a separate argument.

MB

Sorry. A thousand times sorry. I'll just have to be more careful about
butting in into any conversation I haven't followed closely from now on.

AND you've carefully rendered superfluous ANY argument I could have raised
about using surge protectors.

Hopefully I have learned my lesson! ;-)
--
choro
*****

On Nov 12, 1:52 am, "Bill in Co"
wrote:
It almost sounds like you should get one of theUPSsupplies (universal
power supply, with a battery backup, as I recall).

From what you've said above, I think I'd probably bite the bullet and spend
the bucks and do it in your case! I don't think they are all that
expensive, either.

UPS is for protecting unsaved data. (It does no hardware
protection.) Many are simply reciting a 1980 technology problem that
died with DOS and Windows 95/98/ME. Filesystems do not corrupt data.
If a latest version of the file cannot be written, then a filesystem
simply restores a previous version.

Obsolete technology would not only lose the currently unsaved
version. It would also delete previously saved versions. Which is
why so many today worry about things that have long been eliminated.

Power loss while a drive is writing data does not corrupt a drive.
Same was true even for 1960s disk drives. Power loss only means the
last half of a file update might be lost. A risk so tiny that write
caching is used without worry.

To a computer, power loss is so slow that a drive will often
complete a write, then prepare for power off, then wait a long time
for power to actually drop too low. All disk drives first learn about
a power off only when power has already been cut off. True today as
was true 50 years ago. Use the write cache for non-removable drives.
And do not even look back.

westom wrote:
On Nov 12, 1:52 am, "Bill in Co"
wrote:
It almost sounds like you should get one of theUPSsupplies (universal
power supply, with a battery backup, as I recall).

From what you've said above, I think I'd probably bite the bullet and spend
the bucks and do it in your case! I don't think they are all that
expensive, either.

UPS is for protecting unsaved data. (It does no hardware
protection.)

That's simply not true, on both counts. It is /not/ for protecting unsaved
data (it does that too, but it is a side effect, not the reason d'etre). It is
for being able to work uninterrupted through short power outages (like most tend
to be), and for proper system shutdown when the power outage is long. And it
/does/ do hardware protection too, if the line voltage should become abnormally
high. I'm not mentioning surge protection, because, again, it is not the main
function, but it is there too.

--
You'd be crazy to e-mail me with the crazy. But leave the div alone.
--
Whoever bans a book, shall be banished. Whoever burns a book, shall burn.

On Nov 12, 1:39 pm, "MerseyBeat" wrote:
Secondly, I really can't imagine that aUPSwould fail any more frequently
than the likelihood of the main electicity failing. If aUPSsaves any
piece of expensive hardware or some very important data, then, it would seem
to me, to be worth it's weight in gold.

Reciting retail propaganda does not make a fact. If you knew that,
then you also posted each electronics component damaged by a power
failure. You cannot. Probably will not even try. Power failure does
not cause hardware damage - except where hearsay is promoted as fact.

If a UPS does this hardware protection, then you posted the
manufacturer spec numbers that makes that claim. Again you will not.
Recited myths made so popular by hearsay and advertising is also not
relevant to the OP's post. OP is asking about write-caching. Why are
you posting lies that are also not relevant?

A UPS has only one function. Temporary and 'dirty' power so that
unsaved data can be saved. What is some of the 'dirtiest' power
electronics see? Power from a UPS when in battery backup mode.
'Dirtiest' power also causes no damage due to superior protection
already inside every computer. Facts you should have known. And that
have no relationship to the OP's question about write caching.

choro - your concerns are relevant. Dirtiest electricity comes from
a UPS in battery backup mode. Electricity so dirty as to even threaten
small electric motors and power strip protectors. Even that dirtiest
electricity made irrelevant by protection always inside computers -
even the original IBM PC.

On Nov 12, 4:50 pm, Patok wrote:
That's simply not true, on both counts. It is /not/ for protecting unsaved
data (it does that too, but it is a side effect, not the reason d'etre). It is
for being able to work uninterrupted through short power outages (like most tend
to be), and for proper system shutdown when the power outage is long.

Which is also called time to save unsaved data.

Please learn how a typical UPS works. When not in battery backup
mode, then the UPS connects a computer to cleanest electricity - AC
mains. How does that relay inside a UPS stop destructive voltage
increases? It doesn't. But the myth sells a UPS to many who do not
ask damning technical questions. And who also ignore manufacturer
spec numbers.

In the 1970s, design standards required 120 volt electronics to
withstand voltage increases up to 600 volts without damage. Today,
those numbers for computers are even higher. You knew these numbers
before posting? No?

How often are you replacing dimmer switches, digital clocks,
dishwasher, and your furnace due to these voltage increases? You are
not. Excessive voltages are myths that promote retail sales. If
destructive voltages exist, then you are replacing bathroom GFCIs
daily. So what does that UPS protect from? Junk science
fabrications?

UPS outputs some of the 'dirtiest' power a computer will see. Power
that can harm small electric motors and power strip protectors is
still ideal perfect power to all computers. Computers are more
robust.

Meanwhile, these UPS protection fables are irrelevant to the OP's
question about write caching. That unsound concern is also solved by
the filesystem.