12 sendmail.
Prior to V8.10 sendmail, xf transcript files were always created on disk for eachdelivery,
regardless of whether any information ever ended up in them. In fact, 99% of the time, the
xf transcript is created and discarded without ever having been used. Unfortunately, the
sendmail queue directory is disk-based, and therefore is limited in the number of I/O operations
possible per second. Creating and removing useless files is expensive and has been
shown to slow down sendmail.
Beginning withV8.10 sendmail it is possible to create and remove xf transcript files in
memory, rather than on disk, and place them on disk only if they become large or need to
be archived. This was made possible by the torek I/O library supplied withUCB 4.4
versions of Unix. For suchversions, that library is used to create a memory-based file I/O
inside sendmail, and thus speed up sendmail.
On the downside, for systems that lack the torek I/O library, this memory-based disk I/O is
not available. Such systems are those based on System V or pre-4.4 BSD Unix, or Linux.
For all the flavors of Unix supported in devtools/OS, the selection of the type of I/O is
correct. In the rare circumstance that you need to change this setting, you can do so with
this confSTDIOTYPE macro:
define(`confSTDIOTYPE??, `torek??) ?†? select torek I/O
define(`confSTDIOTYPE??, `portable??) ?†? select non-torek I/O
* Prior to V8.
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