IamSpartacus Posted February 14, 2020 Share Posted February 14, 2020 (edited) I have 128GB of RAM in my system (AMD EPYC) and Unraid clearly reads all 128GB but yet only shows half that is available in /tmp or a /ramdisk I've created. I was aware of /dev/shm only allocating half ram but I was under the impression that /tmp would be able to see and use all available ram, and same for a user created ramdisk. Am I missing something? EDIT: It looks like Unraid is caching more than half my RAM but not making that RAM available? Edited February 14, 2020 by IamSpartacus Quote Link to comment
HotelErotica Posted February 15, 2020 Share Posted February 15, 2020 Bumping out of curiosity, I have 256GB of RAM and /tmp only shows me 128GB Quote Link to comment
Squid Posted February 15, 2020 Share Posted February 15, 2020 /tmp is mounted to use 50% of the memory available maximum. Cached memory should be always as much as possible. Cache is always returned to the system when a process needs it, and unused RAM is wasted RAM. https://www.linuxatemyram.com/ Quote Link to comment
IamSpartacus Posted February 16, 2020 Author Share Posted February 16, 2020 7 hours ago, Squid said: /tmp is mounted to use 50% of the memory available maximum. Cached memory should be always as much as possible. Cache is always returned to the system when a process needs it, and unused RAM is wasted RAM. https://www.linuxatemyram.com/ So if I start writing more than 63GB to my ramdisk more ram ram should be allocated on the fly to accommodate? I ask because I'm not seeing that happen. I use my ramdisk for incomplete usenet downloads and when that 63GB is filled I cant write anymore. Meanwhile I have another 40+GB of free RAM apparently doing nothing. Quote Link to comment
trurl Posted February 16, 2020 Share Posted February 16, 2020 2 minutes ago, IamSpartacus said: So if I start writing more than 63GB to my ramdisk more ram ram should be allocated on the fly to accommodate? I ask because I'm not seeing that happen. I use my ramdisk for incomplete usenet downloads and when that 63GB is filled I cant write anymore. Meanwhile I have another 40+GB of free RAM apparently doing nothing. No. Your ramdisk is not resized on the fly. Memory is used as I/O buffer and released to other processes as needed, but this has nothing to do with your ramdisk allocation. Quote Link to comment
IamSpartacus Posted February 16, 2020 Author Share Posted February 16, 2020 2 minutes ago, trurl said: No. Your ramdisk is not resized on the fly. Memory is used as I/O buffer and released to other processes as needed, but this has nothing to do with your ramdisk allocation. And /tmp is the same scenario? Quote Link to comment
Squid Posted February 16, 2020 Share Posted February 16, 2020 If the memory is required, then another process can use it. IE: On a 16Gig system, you will see that rootfs (where /tmp is) is sized at ~ 7.8G. But you can run (quite easily) 3 VMs at 4Gig a piece without running out of memory. The memory used (ie: dashboard) will reflect this. Quote Link to comment
IamSpartacus Posted February 16, 2020 Author Share Posted February 16, 2020 (edited) 36 minutes ago, Squid said: If the memory is required, then another process can use it. IE: On a 16Gig system, you will see that rootfs (where /tmp is) is sized at ~ 7.8G. But you can run (quite easily) 3 VMs at 4Gig a piece without running out of memory. The memory used (ie: dashboard) will reflect this. I'll have to test it again as I could have sworn /tmp was acting the same as my ramdisk. And I switched to using a ramdisk because I like having easy access to it via an SMB share for insight as I use it for a bunch of services (plex and Emby transcoding, downloads, etc.). Edited February 16, 2020 by IamSpartacus Quote Link to comment
Squid Posted February 16, 2020 Share Posted February 16, 2020 5 minutes ago, IamSpartacus said: SMB share Just add this to your smb-extra.conf file on the flash drive [TMP] path=/tmp valid users = andrew write list = andrew Quote Link to comment
IamSpartacus Posted February 16, 2020 Author Share Posted February 16, 2020 8 minutes ago, Squid said: Just add this to your smb-extra.conf file on the flash drive [TMP] path=/tmp valid users = andrew write list = andrew Yea that's what I have for my ramdisk. I will test writing to /tmp again and if it does dynamically assign more ram I will add those SMB settings. Quote Link to comment
Squid Posted February 16, 2020 Share Posted February 16, 2020 It won't ever use more than 50% of your RAM. It will however only use as much as necessary up to 50% Quote Link to comment
IamSpartacus Posted February 16, 2020 Author Share Posted February 16, 2020 Just now, Squid said: It won't ever use more than 50% of your RAM. It will however only use as much as necessary up to 50% Then yes, its of no use to me. That's disappointing that there is no ram directory that I can use more than 50% of my ram with. Quote Link to comment
binhex Posted February 16, 2020 Share Posted February 16, 2020 Then yes, its of no use to me. That's disappointing that there is no ram directory that I can use more than 50% of my ram with.You can do that although this approach isn't a percentage of memory, see here:- Sent from my CLT-L09 using Tapatalk 1 Quote Link to comment
IamSpartacus Posted February 16, 2020 Author Share Posted February 16, 2020 8 minutes ago, binhex said: You can do that although this approach isn't a percentage of memory, see here:- Sent from my CLT-L09 using Tapatalk Oh nice. Yea this could work. Thank you. Quote Link to comment
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