[Tutorial][Experimental][Third-party Plugin available]Reducing OMV's disk writes, also to install it on USB flash

ok, thanks!

I added manually noatime,nodiratime, to /dev/mmcblk0p2 and to the entry with UUID related to sd, is it fine ?

Hi All

I've just installed the plugin as I am running an HP DL360 G7 with SAS raid with external SATA drive enclosures. I didn't want to use the built in SAS drives for the OMV install so it now lives on a Sandisk 8Gb USB stick on the internal USB2 port.

I had a drive in the external enclosure that was detected as the root (/dev/sdj1) but the OMV install is on /dev/sdb. I removed that drive however the plugin was still referring to /dev/sdj1.

I have un-installed the plugin and reinstalled it after a reboot and that seems to have fixed it, now to reinstall /dev/sdj

Thanks for the work on this plugin!

Ok, thanks for the update.

Strange thing is that the root partition didn't move, it's always been on sdb, and sdj is a single ext4 formatted drive with music on it.

Is there a way to manually point the plugin at the correct partion?

I am going to do a clean reinstall of OMV somewhere this weekend. I was thinking of moving to a USB install so I could deploy an extra storage hard disk. Since this plugin is tried and tested for some time, are there any new issues with it? Are there users who use the plugin with an USB for a year or so?

Ralph

Thank you boba and ryecoaaron for porting fs2ram to OMV!

Zitat von bobafetthotmail

I think it is the other way around.
older implementations of TRIM in the kernel (what happens when you place the discard mount option) sucked big way when deleting files (and the TRIM kicked in)
https://patrick-nagel.net/blog/archives/337
Nowadays the impact is minimal (unless you love to delete hundreds of GB of small files repeatedly from the SSD for some reason, which is an unrealistic use case) and should get better.
https://kparal.wordpress.com/2…-option-on-intel-525-ssd/

Debian recommends a weekly trim. Arch threw away `discard` mount option in favor of a weekly fstrim back in 2013.

Zitat von bobafetthotmail

I'm waiting for Antergos to download (Arch linux, easy to install), I want to see if the same issue persists in the latest kernel too before posting bugs in the kernel bugtracker.

Any USB flash memory device I throw in the NAS running OMV 2.2 is recognized as "rotational" device. Yeah even these with a nice controller such as a SanDisk Extreme USB 3.0 (have SMART support and Windows recognizes as a "local disk"). So, #1318 not solved.
Note it's the same on my Arch with kernel 4.4.6 where it's given the "wrong" IO scheduler despite appropriate udev rule. Seems a kernel bug.

BTW I've set swapiness, added a low latency IO scheduler for the flash-mem, and activated zswap in my OMV 2.2. What about informing on some of these upon flashmemory plugin install --with an article in the Wiki? I may write a draft of the later.
swappiness on the Debian wiki
IO-Scheduler on Debian wiki
zwap on Arch wiki (Debian's only has zram)
Interesting discussion on zswap, Reddit

Also, noatime already includes nodiratime, so no need to specify both (just check `man mount` or the source). You can make fstab a bit KISSer

Having properly aligned partitions on the flash memory used for OMV install, avoid the Write Amplification, therefore double lifetime expectancy, as well as write performances (not telling you anything new here).
OMV handled that nicely on the microSDHC that was partitioned from the installer A check and info displayed would be nice for users who may have partitioned their "disk" out of OMV. At any rate it would give users satisfaction their flash storage is optimally aligned. Three neat refs:
https://lwn.net/Articles/428584/
SSDOptimization on Debian wiki (really is about flash-memory storage, not ssd only)
Formatting sd-cards for speed and lifetime

EDIT: added more ref links.

@votdev may also take a look at those info.

Greetings
David

IMHO, most of usb is not good at lifetime as SSD
but these day, pro class USBs seem same as SSD
(for example sandisk extreme, Mushikin Ventura, Corsair Flash Voyager GTX)
actually they use same nand and controller which SSD use
they are also recognized as local disk not removable disk (also support S.M.A.R.T,
but unfortunately TRIM support is not)
costs is same as SSD

I'm currently on SSD 32GB for OMV OS
but I would prefer USB install since it saves one sata and space

so, it would be perfectly fine installing OMV here without modification

I am a huge fan of this plugin. All of the omv installs I have done have been to SSD, DOM, uSD or SD( the latter two obviously benefiting the most). From various incarnations of; pis, thin clients and odroids (not least my newly acquired odroid xu4). Low power consuming, quiet devices.

The plugin is using fs2ram and presumably other tools that I have failed to notice. Im wondering if there might be an option to implement zram? I have been reasonably impressed with it on my netbook. It seems like a logical addition for low memory, flash memory devices.

Hello,

I am running a banana pi with armbian (Linux 4.6.3-sunxi (wheezy)) on a sd-card and installed omv 2.2.1. I also installed omv flash memory plugin. Looking at the notes of flash memory plugin fstab should be changed.

Add noatime and nodiratime to root options. See before and after example lines:
BEFORE:
    UUID=ccd327d4-a1ed-4fd2-b356-3b492c6f6c34 / ext4 errors=remount-ro 0 1
AFTER:
    UUID=ccd327d4-a1ed-4fd2-b356-3b492c6f6c34 / ext4 noatime,nodiratime,errors=remount-ro 0 1
Comment out the swap partition. See before and after example lines (only need to add a # to beginning of the line):
BEFORE:
    UUID=a3c989d8-e12b-41d3-b021-098155d6b21b none swap sw 0 0
AFTER:
    #UUID=a3c989d8-e12b-41d3-b021-098155d6b21b none swap sw 0 0

Looking at may fstab, there are some differences:

# UNCONFIGURED FSTAB FOR BASE SYSTEM
/dev/mmcblk0p1  /       ext4    noatime,nodiratime,discard,defaults,noatime,nodiratime,data=writeback,commit=600,errors=remount-ro      0       0
/var/swap none swap sw 0 0
tmpfs           /tmp            tmpfs   defaults        0       0
# >>> [openmediavault]
UUID=eb9c1dd5-583b-4659-ba93-d521129cd07c /media/eb9c1dd5-583b-4659-ba93-d521129cd07c ext4 defaults,nofail,user_xattr,noexec,usrjquota=aquota.user,grpjquota$
# <<< [openmediavault]

• Do I have to change line 2 and 3 or line 6?
• line 2 already shows the "noatime, nodiratime", but twice. Could I delete "noatime, nodiratime" once?
• What else do I have to change?

Thanks a lot.
Michael

I just installed OMV 3.0 and I playing with it. So far, very impressed! A lot of what I already have on my small server but easily configurable and customisable

My system drive is a USB pendrive inside the box, so thanks also for the flash memory plugin

Looking the logs I found that warning;

Oct 12 22:45:43 ubuntu systemd[1]: Configuration file /lib/systemd/system/folder2ram_startup.service is marked world-writable. Please remove world writability permission bits. Proceeding anyway.

Oct 12 22:45:43 ubuntu systemd[1]: Configuration file /lib/systemd/system/folder2ram_shutdown.service is marked world-writable. Please remove world writability permission bits. Proceeding anyway.

Is it ok to fix the permission or are they needed due to permissions problems during bootup/shutdown?

Did that and bobafettathotmail already updated folder2ram!

Hello,
is flashmem now stable enough to use on OMV and armbian? (i have tried using it a few months back, and I was no able to configure it back then. It was working fine on OMV2 though)

Also, would it help if I turn statistics calculation? My OMV is almost always turned on.

Thank you