I have a real picky tape drive (DLT series) that likes to be fed large chunks
of data at once, otherwise after every 2-4KB of data it halts and rewinds
itself because its cache for writing to the tape is empty.
My best solution to this problem was to use 'tar -b 4096', which sends 4096 x
512-byte blocks at once for a total of a 2MB buffer size. This worked fine for
several weeks, until 2 days ago I got this message (and the backup fails):
st: failed to enlarge buffer to 2097152 bytes.
Free memory shows:
total used free shared buffers cached
Mem: 517036 514468 2568 751908 47804 189488
-/+ buffers/cache: 277176 239860
Swap: 136544 452 136092
Unfortunately, all of the "free" memory right now is eaten up using cache. Is
there a way I can just tell the kernel to allocate memory from the cache for
the buffer? I'm sure there's gotta be a 2MB-sized chunk in that 189MB cache
-somewhere-.
Why doesn't the kernel's get_free_pages() function support moving data around
in memory to get larger chunks for what it needs? I see this same problem
happening in SVGATextMode where allocating space for a NxM character screen
(where NxM >= 16384) fails because there is no contiguous memory space. I think
at least it should be able to use some cache.
Suggestions?
-Byron
--
Byron Stanoszek Ph: (330) 644-3059
Systems Programmer Fax: (330) 644-8110
Commercial Timesharing Inc. Email: [EMAIL PROTECTED]
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