segator Posted March 19, 2015 Share Posted March 19, 2015 Hi, Do you know if it's possible use cache_dirs(based ram) over Cache drive? It's interesting because you have all the space of cache drive and no need extra ram to prevent spin up disk when try to get directory info. Quote Link to comment
garycase Posted March 19, 2015 Share Posted March 19, 2015 Not sure what you're asking here. Cache Dirs is a utility to cache the directories of your disks in RAM so disks don't need to be spun up to access the directories. A cache drive is used to cache disk writes so they'll be quicker than writing directly to the protected array -- writes can occur at "disk speed" instead of requiring 4 disk operations per write (which are required to maintain parity). Quote Link to comment
jonp Posted March 20, 2015 Share Posted March 20, 2015 Not sure what you're asking here. Cache Dirs is a utility to cache the directories of your disks in RAM so disks don't need to be spun up to access the directories. A cache drive is used to cache disk writes so they'll be quicker than writing directly to the protected array -- writes can occur at "disk speed" instead of requiring 4 disk operations per write (which are required to maintain parity). I think what he is asking is if instead of keeping the directories cached in ram, to use a cache device (probably an SSD) to do this instead, saving that oh-so-precious RAM. Quote Link to comment
garycase Posted March 20, 2015 Share Posted March 20, 2015 Yes, that makes sense. Of course then the cache drive has to spin up to access the directories (unless it's an SSD ... in which case it simply needs to exit standby if it's in that mode). I don't see much benefit to this, as Cache Dirs doesn't really use all that much RAM in the great scheme of things when considering how much RAM modern systems have. Quote Link to comment
itimpi Posted March 20, 2015 Share Posted March 20, 2015 I also do not see how such a capability could easily be implemented! The existing cache-dirs. plugin leverages the built-in Linux behaviour of trying to keep in RAM frequently used file/directory information. Trying to engineer in a different mechanism to achieve similar results would almost certainly be very difficult and error-prone. Quote Link to comment
garycase Posted March 20, 2015 Share Posted March 20, 2015 Agree ... applying the old "if it ain't broke, don't fit it" adage, the current Cache Dirs package works quite nicely, so I see no reason to change it Quote Link to comment
segator Posted March 20, 2015 Author Share Posted March 20, 2015 Hi, Thanks for your answers. you are right, i'm talking about using on cache drive SSD anyway about memory cache dir, how much RAM consume on 3rd level directory cached? Do you know if it's working on unraid 6 beta? Quote Link to comment
garycase Posted March 20, 2015 Share Posted March 20, 2015 ... how much RAM consume on 3rd level directory cached? It depends entirely on how many files you have. Read the details on Cache Dirs => there are several options that let you control just what it does/doesn't cache to help control its memory usage. Quote Link to comment
Dallas.toth Posted March 21, 2015 Share Posted March 21, 2015 Basically I think you are asking if there is a Paging File capability to set up a SSD as a Virtual Ram disk. Sort of what windows does. I don't know myself but from the sounds of it I think that is what you are after. Quote Link to comment
Dallas.toth Posted March 21, 2015 Share Posted March 21, 2015 Basically I think you are asking if there is a Paging File capability to set up a SSD as a Virtual Ram disk. Sort of what windows does. I don't know myself but from the sounds of it I think that is what you are after. I found a swapfile plugin but looks so far to be for Unraid 5. Anyone know if it works for 6 or if there is a version for 6 out there? Quote Link to comment
Dallas.toth Posted March 21, 2015 Share Posted March 21, 2015 Basically I think you are asking if there is a Paging File capability to set up a SSD as a Virtual Ram disk. Sort of what windows does. I don't know myself but from the sounds of it I think that is what you are after. I found a swapfile plugin but looks so far to be for Unraid 5. Anyone know if it works for 6 or if there is a version for 6 out there? Found Raid 6 - Basic for now only uses Cache Drive. I have a mounted appdisk that is an SSD and it doesn't support it ATM. Looks to be a active project though for this developer. Worth Watching. http://unraid.zeron.ca/plugins/swapfile/SwapFile.plg Found Unraid 5 https://raw.githubusercontent.com/theone11/swapfile_plugin/master/swapfile.plg Quote Link to comment
segator Posted March 23, 2015 Author Share Posted March 23, 2015 is it swapfile plugin compatible with cache_dir? Quote Link to comment
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