So each enclosure hosts its own RAIDZ2. Have you tested if it can survive loss of USB connectivity? It can happen because of cable damage or movement, and also because of any failure in the enclosure's electronics.
Maybe you could make a target unit file like “jobs.target” and in your timer unit files do “WantedBy=jobs.target”. Then you could do “systemctl start/stop jobs.target”
First, list and save the currently active timers:
```bash
systemctl list-timers --state=active --no-legend | awk '{print $NF}' > /tmp/active_timers.txt
```
Stop all active timers:
```bash
sudo systemctl stop $(cat /tmp/active_timers.txt)
```
Later, restart the previously active timers:
```bash
sudo systemctl start $(cat /tmp/active_timers.txt)
```
> The DC-ROMA RISC-V Pad II starts at $149 for the 4GB RAM version and is already available for pre-order on the DeepComputing store.
> If you get the 16GB RAM variant, the tab is compatible with the Android Open-Source Project (AOSP) Android 15 operating system.
Weird, isn't 4GB RAM enough for Android 15? Or is AOSP compatibility completely separate from Android compatibility?
Who are the phone/tablet manufacturers that are friendliest to rooting or installing open-source Android clones? It's a pain to do that on my Samsung Galaxy devices...
I'm looking to buy a (new) 10'' tablet for that purpose.
No, you're thinking along the right lines. These things are kernel tune ables. If you thumb through the sysfs kernel docs you can find loads of options on this sort of thing.
These settings heavily depends on your OS, hardware, and use-case.
This profile is what I prefer for AORUS 5/RTX3070/i7-12700H/16GB laptops, and despite how terrible the OEM hardware is... this setup will run acceptably well with dual Intel 670p M.2 drives.
The following should work with most Debian variants, but is hardly optimal for every platform. But if your laptop is similar, than it should be a good place to start. One caveat, when ejecting media it may take some time to flush your buffers.
sudo nano /etc/sysctl.conf
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1
# Ignore ICMP broadcast requests
net.ipv4.icmp_echo_ignore_broadcasts = 1
# Disable source packet routing
net.ipv4.conf.all.accept_source_route = 0
net.ipv6.conf.all.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0
net.ipv6.conf.default.accept_source_route = 0
# Ignore send redirects
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 2048
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_syn_retries = 5
net.ipv4.conf.all.log_martians = 1
net.ipv4.icmp_ignore_bogus_error_responses = 1
net.ipv4.conf.all.accept_redirects = 0
net.ipv6.conf.all.accept_redirects = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv6.conf.default.accept_redirects = 0
net.ipv4.icmp_echo_ignore_all = 1
#ban list mem
net.core.rmem_default=8388608
net.core.wmem_default=8388608
#prevent TCP hijack in older kernels
net.ipv4.tcp_challenge_ack_limit = 999999999
#may be needed to reduce failed TCP links
net.ipv4.tcp_timestamps=0
net.ipv4.tcp_rfc1337=1
net.ipv4.tcp_workaround_signed_windows=1
net.ipv4.tcp_fack=1
net.ipv4.tcp_low_latency=1
net.ipv4.ip_no_pmtu_disc = 0
net.ipv4.tcp_sack = 1
net.ipv4.tcp_mtu_probing = 1
net.ipv4.tcp_frto=2
net.ipv4.tcp_frto_response=2
net.ipv4.tcp_congestion_control = cubic
net.ipv4.tcp_window_scaling = 1
kernel.exec-shield=1
kernel.randomize_va_space=1
#reboot on kernel panic after 20 sec
kernel.panic=20
vm.swappiness=1
vm.vfs_cache_pressure=50
#percentage of system memory that can be filled with dirty pages
# run to check io performance with: sudo vmstat 1 20
vm.dirty_background_ratio=60
#maximum amount of system memory filled with dirty pages before committed
vm.dirty_ratio=80
vm.dirty_background_bytes=2684354560
vm.dirty_bytes=5368709120
#how often the flush processes wake up and check
vm.dirty_writeback_centisecs=10000
#how long something can be in cache before it needs to be written
Yeah, a lot of things cost more than a basic laptop. Last I checked, you can get Chromebooks on the order of $20 or so per machine. That metric isn't useful to anybody.
JGit has advanced a lot, and is in use in software handling huge repositories like Gerrit code review system. Java has also had numerous advancements in the past 10 years.
It would be interesting to measure git vs JGit performance today.
It would also be interesting to have JGit developers comment on performance after all this time.
