SG-3100 ram disk question
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I'm planning to enable RAM disk in my SG-3100.
With my current config, I have around 1GB of free RAM.
The size of /var directory is around 650MB.What size of /var should I set? To be safe.
last pid: 26515; load averages: 0.27, 0.32, 0.28 up 3+03:22:25 19:28:04 150 threads: 3 running, 125 sleeping, 22 waiting CPU: 0.0% user, 0.0% nice, 0.6% system, 0.0% interrupt, 99.4% idle Mem: 201M Active, 411M Inact, 209M Wired, 84M Buf, 1231M Free[22.05-RELEASE][root@pfsense.home.arpa]/: du -sh /var 632M /var [22.05-RELEASE][root@pfsense.home.arpa]/: du -sh /tmp 284K /tmp -
Replying to myself, set /var to 850M and /tmp to 80M, boot successfully.
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@mcury "monitor it a while" is going to be the answer (for /tmp and /var). 650 MB sounds pretty big? I've set up RAM disks on most of the routers under our care and /var is usually around 80-120 MB used space, off the top of my head. Just wondering for you if there are extra/old files there to clean up.
Using tmpfs, it won't allocate the RAM until used, but a 3100 only has 2 GB to start with.
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@steveits Thanks for the input.
I suppose the /var size is due to pfblockerng and dnsbl big lists I'm using..
So far its working fine, I'll be monitoring it.
In case of problems, I can perform a clean install, I have the previous config saved here.[22.05-RELEASE][root@pfsense.home.arpa]/var: du -sh unbound/ 482M unbound/ [22.05-RELEASE][root@pfsense.home.arpa]/var/db: du -sh pfblockerng/ 122M pfblockerng/The io in my eMMC is already way lower than it used to be, so its a very good sign already.
[22.05-RELEASE][root@pfsense.home.arpa]/var: iostat -x extended device statistics device r/s w/s kr/s kw/s ms/r ms/w ms/o ms/t qlen %b flash/sp 0 0 0.0 0.0 7 0 0 7 0 0 mmcsd0 1 0 13.1 16.5 1 13 0 6 0 0 mmcsd0bo 0 0 0.0 0.0 0 0 0 0 0 0 mmcsd0bo 0 0 0.0 0.0 0 0 0 0 0 0 [22.05-RELEASE][root@pfsense.home.arpa]/var: uptime 11:08PM up 2:09, 1 user, load averages: 0.40, 0.40, 0.28 -
@mcury said in SG-3100 ram disk question:
io in my eMMC is already way lower
Yep.... :)
@mcury said in SG-3100 ram disk question:
I suppose the /var size is due to pfblockerng and dnsbl big lists I'm using..
So if it's using 480 MB in RAM and 680 in RAM disk....1 GB just for that? Not saying you're wrong to do so, but that leaves only half for the rest. What is the memory usage on the dashboard? (am curious)
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[22.05-RELEASE][root@pfsense.home.arpa]/root: iostat -x extended device statistics device r/s w/s kr/s kw/s ms/r ms/w ms/o ms/t qlen %b flash/sp 0 0 0.0 0.0 7 0 0 7 0 0 mmcsd0 0 0 2.7 5.1 1 11 0 6 0 0 mmcsd0bo 0 0 0.0 0.0 0 0 0 0 0 0 mmcsd0bo 0 0 0.0 0.0 0 0 0 0 0 0 -
Mmm, 650MB is large for a 3100 but if you have lists that big you might need it. That wouldn't be possible in previous pfSense versions. Just something to be aware of if you have any older installs.
You might consider if you really needs lists that big.
Steve
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@mcury "df -h"? Now I'm more curious, since 26% of 2017 is only 524.
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@steveits said in SG-3100 ram disk question:
@mcury "df -h"? Now I'm more curious, since 26% of 2017 is only 524.
[22.05-RELEASE][root@pfsense.home.arpa]/root: df -h Filesystem Size Used Avail Capacity Mounted on /dev/diskid/DISK-D4EC8498s2a 7.0G 1.4G 5.1G 21% / devfs 1.0K 1.0K 0B 100% /dev /dev/diskid/DISK-D4EC8498s1 34M 2.0M 32M 6% /boot/u-boot tmpfs 80M 236K 80M 0% /tmp tmpfs 850M 186M 664M 22% /var /usr/local/bin 7.0G 1.4G 5.1G 21% /var/unbound/usr/local/bin /usr/local/lib 7.0G 1.4G 5.1G 21% /var/unbound/usr/local/lib devfs 1.0K 1.0K 0B 100% /var/dhcpd/dev /lib 7.0G 1.4G 5.1G 21% /var/unbound/lib devfs 1.0K 1.0K 0B 100% /var/unbound/dev /var/log/pfblockerng 850M 186M 664M 22% /var/unbound/var/log/pfblockerng /usr/local/share/GeoIP 7.0G 1.4G 5.1G 21% /var/unbound/usr/local/share/GeoIP -
@stephenw10 said in SG-3100 ram disk question:
Mmm, 650MB is large for a 3100 but if you have lists that big you might need it. That wouldn't be possible in previous pfSense versions. Just something to be aware of if you have any older installs.
You might consider if you really needs lists that big.hm, so far so good
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@mcury said in SG-3100 ram disk question:
tmpfs 850M 186M 664M 22% /var
Hmm, so it's only using 186 MB for some reason, not 650. Looks like it's all pfB.
side note: the /usr/local/share/GeoIP I looked at is only 26 MB.
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@steveits Strange, I put both configuration in Meld for comparison, and it seems that this ram disk change doesn't go to the xml config.
So, in the future in case of a new install, I can restore this configuration and then enable RAM disk, but this won't be automatic.
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@mcury It should be in the config. Look for:
<use_mfs_tmp_size>128</use_mfs_tmp_size>
<use_mfs_var_size>256</use_mfs_var_size>
and
<use_mfs_tmpvar/> -
@steveits Oh yes, you are correct, I don't know how I missed that :)
So, to disable I can just remove that line:
use_mfs_tmpvar></use_mfs_tmpvar>That is useful because I noticed that when you perform a clean install and restore a config, during packages reinstall there is a lot of RAM usage, which could break things for me..
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Yes, that's the config line that triggers creating and using the ramdisks.
You'll find that the usage is much higher when pfBlocker updates. Probably around double what you see there now.
Steve
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@stephenw10 said in SG-3100 ram disk question:
You'll find that the usage is much higher when pfBlocker updates. Probably around double what you see there now.
hm, ramdisk for /var is set to 850M, and not problems yet, I've been monitoring and so far so good.
Do you think I'll face problems with this size?In case of a pfsense reinstall and config restore, I would disable the ram disk just to be safe.
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I think that's big enough for pfBlocker to update.
I'm not sure if a RAM disk that size is sustainable on the 3100. But it could be the years of battling kernel memory limits we had before we switched to tmpfs making me paranoid!
Before that ~120MB was the most you could set. That's what I use on most installs:
[22.05-RELEASE][admin@fw1.stevew.lan]/root: df -h Filesystem Size Used Avail Capacity Mounted on /dev/diskid/DISK-9E18E959s2a 7.0G 2.3G 4.1G 36% / devfs 1.0K 1.0K 0B 100% /dev /dev/diskid/DISK-9E18E959s1 34M 2.0M 32M 6% /boot/u-boot tmpfs 80M 2.2M 78M 3% /tmp tmpfs 120M 34M 86M 28% /var devfs 1.0K 1.0K 0B 100% /var/dhcpd/devSteve
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@stephenw10 I'll be testing and in case of problems I'll post here to help others that try this same approach.
Thanks stephenw10
I was getting around 2TB a year of writes before making this change.. Almost 5 years using device already :)
[22.05-RELEASE][root@pfsense.home.arpa]/root: iostat -x extended device statistics device r/s w/s kr/s kw/s ms/r ms/w ms/o ms/t qlen %b flash/sp 0 0 0.0 0.0 8 0 0 8 0 0 mmcsd0 0 0 1.5 4.0 1 10 0 6 0 0 mmcsd0bo 0 0 0.0 0.0 0 0 0 0 0 0 mmcsd0bo 0 0 0.0 0.0 0 0 0 0 0 0 [22.05-RELEASE][root@pfsense.home.arpa]/root: uptime 10:25AM up 18:38, 1 user, load averages: 0.29, 0.28, 0.25 -
I am a bit confused about the RAM disk limits.
At my SG-3100 the limit is:Maximum total size of all RAM disks cannot exceed available memory: 269.75 MiBTo which packages/options/values/... is the limit referring/calculating?
I do not use RAM disks any longer since my issues, just to still curiosity
.Regards
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You are probably running an older version before we switched to tmpfs?
