On 21/07/2012 3:11 p.m., Eliezer Croitoru wrote:
On 7/20/2012 5:17 PM, haggismn wrote:
Hi all,
I am a bit of a noob with squid, as well as USB flash storage, so please
bear with me.
I have squid up and running on a USB equipped dd-wrt router. I have
plugged
in a 8gb USB flash drive, of which 4gb are allocated for the squid
cache.
Currently I am using mostly default settings, ie cache_dir ufs
/mnt/sda1/cache 4096 16 256
Nice.
I am aware that by using a USB flash drive with squid, the lifespan
of the
drive will be greatly decreased, due to the limited number of write
cycles
each block on the disk has. I was therefore wondering if it is
possible to
set up the caching so that it reduces the number of writes made onto the
disk. I have been looking at options like minimum_object_size, which
I have
set to 8 KB, thus reducing the number of small files written. Will
this help
in any way? Are there other measure I can take which might help? I
have been
looking at using COSS storage, with a low max-stripe-waste, with the
intention that this might reduce write frequency. As far as I can
tell, this
will write to the disk in 1MB chunks. Might this help by any chance? Are
there any other measures that might help, for example formatting the
flash
drive in a certain way (although likely limited to FAT32).
dont think about the lifespan of the drive because if they die they die.
cache is "by all means possible write to disk what you can" excluding
the ram cache.
this is the basic idea of cache.
USB flash drives are not that fast compared to many HD but can still
be faster then the link you have.
the basic thing is to disable logging which you dont really need to
store on most of wrt devices.
the "minimum_object_size" is not important in this case (my opinion).
COSS is not being used anymore and there is a rockstore something.
anything is better then fat32 in you case of linux OS.
the reiser FS is ment for lots and lots of small files.
ext2/3/4 and reiser fs has an option of "noatime" that can reduce some
drive access but it has a risk of corruption the FS.
in you case of 4GB cache it really not suppose to be a big deal if you
will loose it unless you have more data on it.
i dont remember exactly but the size of the cache dir suppose to be in
use with your ram size and for a DD-wrt device that dosnt have much
ram 4gb of cache dir will might not be a good idea.
32-bit OS : 10MB per GB
64-bit OS: 15MB per GB
I'd set the min-size parameter on cache_dir instead of the global
minimum_object_size limit. A lot of small objects can be kept in RAM
cache easily enough without affecting disk lifetime.
Amos
