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is there a way to check if disk cache is working on a regular sata disk?

i see "asking for disk cache failed" error messages, but discovered my laptop has a 1gb solid state drive without a partition. i saw it in disk utility. so if i can confirm that the hdd has a working cache then my next goal will be to setup ubuntu to use the solid state for swap instead of the swap area on the hdd.

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Copying a file with a size smaller than your HDD cache should be "instantaneous" (very fast, depends on the memory to sata transfer rate). Sending a file that's larger will block (go as slow as the HDD write) once the cache is full. – Alexis Wilke Apr 7 '13 at 22:16

You should try to copy a file on the disk and then you should type

free -m

in your terminal. You will be able to see the amount of used cache space and the amount of free cache space.

Page with info.

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confirmed cache is working, so error must be coming from solid state, which is /dev/zram0 Now how do I tell Ubuntu to use /dev/zram0 for swap? – Stephen Bond Apr 9 '13 at 22:49
That should be posted in another question. =) – Gav Apr 9 '13 at 23:03
If an answer is correct you should accept it. Instructions here. – Gav Apr 11 '13 at 5:24

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