noacess Posted March 9, 2020 Share Posted March 9, 2020 Hey everyone, I recently rebuilt my unraid server and I'm seeing some strange cache write speed behavior. If I write to a user share that has use cache set to Yes via SMB I can copy at about 280 MB/s which is slow. If I enable disk shares and do the same copy direct to the cache drive share I get well over 1 GB/s which is what I'd expect. The only thing I've tried so far is enabling Direct IO but that didn't help. The cache drive is a hardware raid of SAS3 SSDs. The PC I'm copying from has a PCIE 4.0 nvme disk in it. Diagnostics attached. Any help would be appreciated! Thanks tower-diagnostics-20200309-1707.zip Quote Link to comment
testdasi Posted March 9, 2020 Share Posted March 9, 2020 It's normal. Shfs (the magic behind Unraid shares) has an effective speed limit of 300MB/s to 500MB/s depending on various factors. What I have been doing is to have custom smb config that targets /mnt/cache directly (instead of enabling disk shares) to get max performance. Quote Link to comment
SpeedyVV Posted April 15, 2020 Share Posted April 15, 2020 On 3/9/2020 at 9:16 PM, testdasi said: ... What I have been doing is to have custom smb config that targets /mnt/cache directly (instead of enabling disk shares) to get max performance. Hey, any chance you can do this "custom smb config that targets /mnt/cache directly" thingy? Thanks Quote Link to comment
noacess Posted April 15, 2020 Author Share Posted April 15, 2020 27 minutes ago, SpeedyVV said: Hey, any chance you can do this "custom smb config that targets /mnt/cache directly" thingy? Thanks Below is what works for me. I usually just write 1 file through the user share and then once the folder structure is created I do the rest of my writes through the cache share. Its clunky, but it works for now until I can think of a more elegant solution. [cacheShare] path=/mnt/cache valid users = whoever write list = whoever Quote Link to comment
SpeedyVV Posted April 15, 2020 Share Posted April 15, 2020 Thanks for the quick reply, but I am not sure I get how this works. i'm a bit slow So are you saying you create a new user share called "cacheShare"? Where are you creating this smb config? I have Disk Shares enabled. Should I turn that off? Quote Link to comment
noacess Posted April 15, 2020 Author Share Posted April 15, 2020 If you stop your array, go into settings, then click on SMB there is a section called "Samba extra configuration:" That's where you paste the config I shared. After you start the array you should now see an extra share when you browse to your server. You don't need to create it under the "Shares" area of unraid. I would turn off disk shares unless you need it for something specific. 1 Quote Link to comment
SpeedyVV Posted April 15, 2020 Share Posted April 15, 2020 thanks for your help! Quote Link to comment
Squid Posted April 15, 2020 Share Posted April 15, 2020 47 minutes ago, noacess said: I would turn off disk shares unless you need it for something specific. What you've done is the exact same thing as enabling disk shares and not exporting SMB shares except for the cache drive. Quote Link to comment
bonienl Posted April 15, 2020 Share Posted April 15, 2020 2 hours ago, noacess said: until I can think of a more elegant solution. For all disk shares set Export=No, except for cache set Export=Yes Quote Link to comment
noacess Posted April 15, 2020 Author Share Posted April 15, 2020 2 hours ago, bonienl said: For all disk shares set Export=No, except for cache set Export=Yes I was referring to my hack of copying a single file via user shares to create directory structures and then copying the rest of the files via the cache share because of transfer speed being comparatively slow through user shares when writing to cache. Quote Link to comment
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