intermittents are hideous to track down. Especially since there's so much error recovery built in these days.sql look like it involves intense disk traffic
wikipedia said:
Buffer management[edit]
SQL Server
buffers pages in RAM to minimize disk I/O. Any 8 KB page can be buffered in-memory, and the set of all pages currently buffered is called the buffer cache. The amount of memory available to SQL Server decides how many pages will be cached in memory. The buffer cache is managed by the
Buffer Manager. Either reading from or writing to any page copies it to the buffer cache. Subsequent reads or writes are redirected to the in-memory copy, rather than the on-disc version. The page is updated on the disc by the Buffer Manager only if the in-memory cache has not been referenced for some time. While writing pages back to disc,
asynchronous I/O is used whereby the I/O operation is done in a background thread so that other operations do not have to wait for the I/O operation to complete. Each page is written along with its
checksum when it is written. When reading the page back, its checksum is computed again and matched with the stored version to ensure the page has not been damaged or tampered with in the meantime.
[23]
is there a hardware disk diagnostic that doesn't erase the disk ?
Reason i ask is
back when slide rules roamed the Earth and i was a young man
our plant computer suffered random crashes about once a month.
A good clue was one day it printed out a report that was months old
that shouted to us "Disk Error" because printer output got spooled to disk until printer caught up.
Sure enough - that Flintstones moving head disk had four different seek speeds depending on how many tracks it had to traverse to reach the desired one.
Disk exerciser program found it failed every time the head reached its highest speed
with a 'scope we found that an op-amp in the track counter circuit had lost drive capability,
it didn't have enough slew rate to accurately report the tracks going by
so sometimes the head stopped on the wrong track...
causing a "Load & Execute Data" event
Anyhow a forty cent opamp fixed that
but what a lesson i learned(see my signature).
Where I'm headed with this is
if you can run a hardware check on your disk , i'd suggest it
my boring anecdote above is from when this was a state of the art terminal
and that disk drive cost several weeks' wages
nowadays hardware is incredibly cheap
my local computer shop charged me only thirty bucks to move all my files to a brand new drive and install it.
old jim
