can I freeze I/O for some time to a given disk / md / dm
Quoted 10 lines · Tomasz Chmielewski
Quoted 4 lines
Is it possible to "freeze I/O" for some time to a given disk / md / dm device?
Say, "freeze I/O" so that userspace waits for any response for 30, 60 seconds or more?
For real disks you can use
/sys/block/sdX/device/unload_headsto achieve something similar (seeDocumentation/laptops/disk-shock-protection.txtin the kernel source about how to use it). That won't work for md/dm devices though.
For drives which don't support "unload_heads" plain hdparm should work:
hdparm -Y /dev/sdX
(possibly repeated in a loop for some time).
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Tomasz Chmielewski http://wpkg.org