Problem: RAM disk/drive on Xbian, how to use zramswap?
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19th May, 2023, 06:29 AM
Post: #1
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RAM disk/drive on Xbian, how to use zramswap?
Hello,
one Kodi plugin downloads repeatedly a file worth tens of MB data and to save SDHC card writing cycles, I have found using "df -Th", that only tmpfs (RAM based filesystem per my understanding) is /dev and /run # df -Th|grep tmpfs Code: devtmpfs devtmpfs 1.6G 71M 1.5G 5% /dev I may utilize /dev/bigfile.name if i "chown xbian /dev", but since it may not be good practice, but /run seems to have already writing permissions for all users "Access: (1777/drwxrwxrwt)". Beside that I was able to do: Code: mkdir -p /mnt/tmpfs Yet someone suggested me to use zram with lz4 compression (claiming to be better compression than Xbian default lzo-rle) to save the space. Though i have doubts about this approach since zram is slower than regular tmpfs and if tmps/memory pressure is high, it will then move to zram swap per my understanding). But anyway if i want to do it, i tried these steps (failed): # zramctl --output-all Code: NAME DISKSIZE DATA COMPR ALGORITHM STREAMS ZERO-PAGES TOTAL MEM-LIMIT MEM-USED MIGRATED MOUNTPOINT # mount -t ext4 /dev/zram0 /mnt/zram Code: mount: /mnt/zram: /dev/zram0 already mounted or mount point busy. # mount -t tmpfs /dev/zram0 /mnt/zram # df -h Code: /dev/zram0 1.8G 0 1.8G 0% /mnt/zram I am able to mount it automatically using /etc/fstab line: Code: /dev/zram0 /mnt/zram tmpfs size=100M,mode=0755,uid=xbian 0 0 I could do: # swapoff -a;zramctl --algorithm lz4 --streams 4 --size 128M /dev/zram0 && swapon # zramctl --output-all Code: NAME DISKSIZE DATA COMPR ALGORITHM STREAMS ZERO-PAGES TOTAL MEM-LIMIT MEM-USED MIGRATED MOUNTPOINT Code: Swap: 0B 0B 0B I could write file to /mnt/zram/ but i see no zram usage: # df -h /mnt/zram /mnt/tmpfs Code: Filesystem Size Used Avail Use% Mounted on # zramctl Code: NAME ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT # free -h Code: total used free shared buff/cache available and test the speed: ioping -R /mnt/zram -R, -rapid test with rapid I/O during 3s (-q -i 0 -w 3) Code: --- /mnt/zram (tmpfs /dev/zram0 100 MiB) ioping statistics --- vs regular tmpfs: Code: --- /mnt/tmpfs (tmpfs tmpfs 100 MiB) ioping statistics --- # fdisk -x /dev/zram0 Code: Disk /dev/zram0: 128 MiB, 134217728 bytes, 32768 sectors # lsblk -a Code: NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT Do you have idea on /etc/fstab line to mount zram based filesystem please? |
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25th May, 2023, 04:37 AM
Post: #2
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RE: RAM disk/drive on Xbian, how to use zramswap?
Simple answer:
xbian-package-zram-swap /etc/default/zram-swap |
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12th Jun, 2023, 06:50 PM
Post: #3
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RE: RAM disk/drive on Xbian, how to use zramswap?
> xbian-package-zram-swap
did "apt install xbian-package-zram-swap" -> "xbian-package-zram-swap is already the newest version (1.0.8)." > /etc/default/zram-swap is a config. file apparently, thanks. Being unsure how to modify it, i assumed i need to somehow activate zram so i did: Quote:ZRUNSHM=1 After reboot, it caused following in "zramctl --output-all" output: Quote:/dev/zram2 1M 44K 743B lzo-rle 4 1 24K 0B 24K 0B /run/shm (only 1MB? Copying file to it says: No space left on device) Quote:# grep -v "#" /etc/default/zram-swap|grep . and mount: Quote:/dev/zram2 on /run/shm type ext2 (rw,nosuid,noatime) Quote:# swapon Setting SWAPFILE=/mnt/zram not apparently changed outputs of above commands (file existed before reboot, after reboot not exist) I wanted to have proper zram 128M partition and proper grow-able zramswap... any idea what to try please? |
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12th Jun, 2023, 08:11 PM
Post: #4
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RE: RAM disk/drive on Xbian, how to use zramswap?
Moving shm to zram is complete nonsense in my opinion
Ever googled for zswap? Since you obviously want to do everything yourself I can't help you there. and - please don't be angry - I don't have much desire to do that anymore either |
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17th Nov, 2023, 01:05 PM
Post: #5
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RE: RAM disk/drive on Xbian, how to use zramswap?
I learned about zswap on Google. I'm still having problems, but thanks for your feedback anyway.
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11th Dec, 2023, 02:51 PM
Post: #6
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RE: RAM disk/drive on Xbian, how to use zramswap?
(12th Jun, 2023 08:11 PM)Nachteule Wrote: Moving shm to zram is complete nonsense in my opinion I find it necessary to search for the right keywords to extract data. I'm doing research based on your suggestion. Looking forward to finding a solution. |
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27th Feb, 2025, 11:14 AM
Post: #7
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RE: RAM disk/drive on Xbian, how to use zramswap?
This sounds like something from a Linux or performance optimization discussion, maybe about memory management? Are you troubleshooting something specific, or just sharing a frustrating exchange?
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28th Jun, 2025, 06:58 PM
Post: #8
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RE: RAM disk/drive on Xbian, how to use zramswap?
Have you considered using zramfs instead of zram0 to mount directly as a filesystem? And have you tried writing large files to /mnt/zram to see when ZRAM actually compresses and takes up RAM? Because according to the parameters you shared, ZRAM is not "forced to work" due to the large amount of free memory.
Among Us Online |
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3rd Jul, 2025, 11:49 AM
Post: #9
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RE: RAM disk/drive on Xbian, how to use zramswap?
(12th Jun, 2023 08:11 PM)Nachteule Wrote: Eaglercraft Moving shm to zram is complete nonsense in my opinionZswap is smarter for many workloads because it defers actual disk swapping. It's good on devices with actual swap partitions. On the other hand, zram is good on devices without disks, like many Raspberry Pi systems. |
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