Limiting Disck Cache

[Ivan Garcia Sainz-Aja <ivangsa@yahoo.es>]

Hi all,

how can i limit the amount of this cache linux uses?

i'm using an external usb hd for playing movies/mp3 but
after a time of usage the memory becomes full and the system 
virtually unusable and i got to umount/mount the drive to 
keep working

root@thinkpad:~# cat /proc/meminfo
        total:    used:    free:  shared: buffers:  cached:
Mem:  775114752 772341760  2772992        0  7421952 609456128
Swap: 348323840 14917632 333406208
MemTotal:       756948 kB
MemFree:          2708 kB
MemShared:           0 kB
Buffers:          7248 kB
Cached:         593088 kB
SwapCached:       2084 kB
Active:          41492 kB
Inactive:       664144 kB
HighTotal:           0 kB
HighFree:            0 kB
LowTotal:       756948 kB
LowFree:          2708 kB
SwapTotal:      340160 kB
SwapFree:       325592 kB

which is mad


thanks a lot
ivan