Mail Archives: opendos/2000/09/15/20:20:24
I have never checked this out. I never use delayed writes. If I had a UPS, I
might use delayed writes. It is way too dangerous to use without a UPS.
However, I would have thought it should be capable of 24 drives. I only use
it for reads. If this person has a UPS, then delayed writes can be used,
otherwise I would recommend not using delayed writes. That was always a pet
peeve I have had with SMARTDRV, it's default is delayed writes. If you have
a power loss, brown out, or a system lockup, you are screwed.
You can lose all the data contained in the cache and possibly mess up the
FAT. Also drive full error can also mess up the drive with delated writes. I
do not trust delayed writes and and would only use it on a stable OS and
with a UPS installed. That definately leaves out MS OSes. In fact the only
OS I would trust using delayed writes is Linux or some other derivative of
UNIX. I maight possibly trust NT with delated writes with a UPS installed as
you can also shut down PIDs on it and save it from a crash. But I am not
that confident about NT yet. A Netware and other dedicated servers with a
UPS would also probably be pretty safe. There are utilities and some cache
programs have an automatic flush when you do the three finguer solute,
however, when the three finger solute does not do anything because the
computer is frozen, you run the high risk of a messed up drive(s).
I recently had a disaster with WINDOZE 95. I lost almost the whole WINDOZE
directory structure. WINDOZE would not boot and could not find the files it
needed. This happened right after WINDOZE froze. Unfortunately, I had just
removed Ontrack's Fit-it utilities, else I could have restored the last disk
image. I did manage to save most of my files I needed by using Norton's
Diskeditor under DOS. WINDOZE had put invalid directory entries in for three
files. I faked those files by re-editing their entries, thus the rest of the
files located after those entries were now available. I was then able to
boot to WINDOZE and zipped up all the files I needed and placed them on FAT
16 partitions. However, somehow I forgot to move the zipped files for
Outlook Express and lost all of my saved and unread mail. Stupid mistake,
but I'll bet anything it was cause by SmARTDRV (Stupid Drive.) I forgot to
turn off the delayed writes the last time I had to re-install WINDOZE. (A
frequent occurance.) I just dumped 95 and am using NT 4.0.
Pat
----- Original Message -----
From: "Alex Venn" <aven AT ukgateway DOT net>
To: <opendos AT delorie DOT com>
Sent: Friday, September 15, 2000 2:28 AM
Subject: NWCache limits
> I've recently had an unexpected problem reported to me (because I
> recommended DRDOS 7.03) with NWCache. This person is perfectly happy
> with DRDOS except for one thing - apparently NWCache refuses to
> delayed-write cache all of her logical drives even when a drive is
> specifically "forced". It looks as if only the first eight are being
> delayed-write cached if the status display is to be believed.
> Smartdrv has no problems with her sixteen logical drives apart from it's
> rather pedestrian performance (with an app specifically optimized for
> speed with NWCache).
>
> Is there a problem with NWCache and delayed-write caching a large number
> of logical drives ?
>
> Alex.
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