Why is restore so slow?

[Larry McVoy]

In article <6511 at stpstn.UUCP> lerman at stpstn.UUCP (Ken Lerman) writes:
>In article <480 at appserv.Eng.Sun.COM> lm at Eng.Sun.COM writes:
>>
>>I believe that a key component to the slowness of restore is the synchronous
>>nature of directory operations in the Unix file system.  For example, a create,
>Has anyone out there with the appropriate source done some measurement
>of where the time goes in restore?  How many reads/writes does it do?
>How long does each take?  Do those figures seem reasonable? ...etc...

Well, I didn't want to tip my hand, but someone at Sun actually tried turning
off the sync writes (dir ops) while restoring a system.  A speed up of 4X
is what I remember, but I might be a little off.  Your mileage may vary.

NVRAM in the disk interface is the easy answer, a option to mount is the
sleazy answer.
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Larry McVoy, Sun Microsystems     (415) 336-7627       ...!sun!lm or lm at sun.com