Re: disable GUI/X?
El Wed, 19 Jun 2024 08:47:58 +0200 va escriure el següent: > On Wed, Jun 19, 2024 at 04:39:50AM -, David Chmelik wrote: > > On Tue, 18 Jun 2024 22:39:15 -0400, Felix Miata wrote: > > > > > David Chmelik composed on 2024-06-19 02:24 (UTC): > > > > > >> How can I disable GUI/X for next boot? I just want to run it > > >> when I decide as startx/startxfce/etc. > > > > > > # systemctl get-default [...] > > > What about in the case I use SysVInit so don't have systemctl? > > Then you have an /etc/init.d/xdm (or gdm, or..., depending on your > display manager). And, if you don't feel like managing it manually, > you have update-rc.d, which comes with a manual page. > > Cheers Just mv softlinks in /etc/rc*.d/ that begins with uppercase to lowercase. In my case, S04lightdm -> s04ligthdm. But many time ago I removed completely lightdm and any session manager. If I want X session, I start with xfce4-session, in my case. Thus, I run X without root privileges.
Re: Having ten thousands of mount bind causes various processes to go into loops
El Fri, 14 Jun 2024 11:30:50 +0200 Julien Petit va escriure el següent: > > What processes are CPU hungry? > > On a vanilla debian 11 : udisksd, gvfs-udisks2-vo, (fstrim), find > > > Perhaps it is not a Debian-specific bug, just more active usage of > > sandboxing in systemd. If some applications have troubles parsing > > /proc/mounts then bugs should be filed against them. > > It seems to happen with all processes accessing mounts. And since > disabling sandboxing with php fixed the problem for the php process, > it looks like it is linked to sandboxing. > > > However do you need shared subtrees? It may cause exponential > > growth of number of moutpoints, see > > We only use mount bind to share an initial folder with other users > with different access rights (rw or ro). So we probably don't need > shared subtrees (as long as mount bind doesn't rely on it). I'm not > really familiar with subtrees though. In my understanding, it is used > for chroot or containers and that's something we don't use. When i > list our mounts, it seems they are by default in shared mode. If the > default before was "private", it might be why it used to work and it > stopped. > I'm gonna test the effect of setting them to private. > > Thanks for your help > Just to learn about it. What about using acl rather than bind mounts? What should be the problem in this solution? Thanks.
Re: NVidia 340 video driver in Bookworm?
El Fri, 07 Jun 2024 14:56:23 -0700 Van Snyder va escriure el següent: > On Fri, 2024-06-07 at 22:47 +0200, Hans wrote: > > Just a hint: Sometimes the nvidia-config module says, you need > > 340.xx, but this is not always true. My card (with th eolder > > kernel) was running 390.xx, although th esystem told me, I have to > > use 340.xx. 390.xx was running like a charm, 340.xx crashed. So it > > lied. > > > > Sorry, that I can help no further and for the bad news, but do not > > try too much - I fear, you will fail! > > So far, this is the best advice, so don't apologize. > > I had assumed that when NVidia said I need 340 that it is undoubtedly > true. I'll try 390. > Have you tried "nvidia-detect" package? This tells you what driver you need. In my machine, I installed nvdia-tesla-470-driver and it works fine.
Re: Passwords
You don't need a live-usb/cd. If your boot system is grub you only have to change command to exec=/bin/bash Once you are in your system you can change root password and others. Toni Mas Missatge de Stanislav Vlasov del dia dt., 17 de gen. 2023 a les 7:15: > > вт, 17 янв. 2023 г. в 11:01, David : > > > I have forgotten my password to a Debian PC using an SD stick as it's > > main drive. > > > Looking on the internet it says the passwords are stored in /etc/passwd > > and /etc/shadow > > In /etc/shadow only password's hashes, some data, one-way calculated > from password string. > > > The password string in /etc/shadow looks as if it's encoded, how can I > > read this string? > > You can't. > But you can set new password, if you boot from live-usb/live-cd, mount > your system to dir and run `chroot dir && passwd $user` > > -- > Stanislav >
Re: update, reboot required?
I restart Dbus from time to time. Actually, I stop Dbus if i don't need, that is when I do not use X (almost allways). Do you mean my action is not effective? Toni Mas Missatge de piorunz del dia ds., 19 de març 2022 a les 5:55: > > On 19/03/2022 02:32, Lee wrote: > > How to tell if I need to reboot the machine after updating the software? > > install "needrestart" package. > > Description: needrestart checks which daemons need to be restarted after > library upgrades. > It is inspired by checkrestart from the debian-goodies package. > > Features: >- supports (but does not require) systemd >- binary blacklisting (i.e. display managers) >- tries to detect required restarts of interpreter based daemons > (supports Java, Perl, Python, Ruby) >- tries to detect required restarts of containers (docker, LXC) >- tries to detect pending kernel upgrades >- tries to detect pending microcode upgrades for Intel CPUs >- could be used as nagios check_command >- fully integrated into apt/dpkg using hooks > > -- > With kindest regards, Piotr. > > ⢀⣴⠾⠻⢶⣦⠀ > ⣾⠁⢠⠒⠀⣿⡁ Debian - The universal operating system > ⢿⡄⠘⠷⠚⠋⠀ https://www.debian.org/ > ⠈⠳⣄ >
Re: User group "users"
Please, note that's my own criteria. - Each new user must have their own group to prevent security issues. - Most of users are per-app users, following (more or less Android methods). So only real (login) users are added manually in the GID=100. Thus they can share what they want only who then want with no acl complexity. Toni Mas GPG 3F42A21D84D7E950 Sent with ProtonMail Secure Email. ‐‐‐ Original Message ‐‐‐ El divendres, 21 de gener 2022 a les 18:51, Thomas Hochstein va escriure: > Roberto C. Sánchez schrieb: > > > > > New users have gid 100 set as their primary group by default. So, new > > > > > > > > users are members of the group without having to be added to the group > > > > > > > > in /etc/groups. > > That depends on your configuration. > > | # /etc/adduser.conf: `adduser' configuration. | # See adduser(8) and > adduser.conf(5) for full documentation. [...] | # The USERGROUPS variable can > be either "yes" or "no". If "yes" each | # created user will be given their > own group to use as a default. If | # "no", each created user will be placed > in the group whose gid is | # USERS_GID (see below). | USERGROUPS=yes | | # > If USERGROUPS is "no", then USERS_GID should be the GID of the group | #` > users' (or the equivalent group) on your system. > > | USERS_GID=100 > > > Quite right. It seems that I probably made that change a very long time > > > > ago, long enough ago so that it just seemed like the standard > > > > configuration to me. > > > From https://wiki.debian.org/UserPrivateGroups: > > | Debian has been using (creating) user private groups by default almost > > | from the beginning. However, UPGs where not fully enabled on newly > > | installed systems since release 2.2., because the central umask > > | adjustment for UPGs, as configured in /etc/login.defs, was broken with > > | the inclusion of PAM. This feature was only reintroduced with > > | libpam-umask in release 6.0 (Squeeze). > > -thh signature.asc Description: OpenPGP digital signature
Re: write only storage.
I use to backup my iPhone's photo library using a stfp connection (all in the same directory in my PC). Thus, I can chattr +i the only directory needed and nobody can remove. I cannot understand why chattr does not achieve you. Toni Mas GPG 3F42A21D84D7E950 Sent with ProtonMail Secure Email. ‐‐‐ Original Message ‐‐‐ El dimarts, 21 de setembre 2021 a les 17:53, Tim Woodall va escriure: > I would like to have some WORM memory for my backups. At the moment > > they're copied to an archive machine using a chrooted unprivileged user > > and then moved via a cron job so that that user cannot delete them > > (other than during a short window). > > My though was to use a raspberry-pi4 to provide a USB mass storage > > device that is modified to not permit deleting. If the pi4 is not > > accessible via the network then other than bugs in the mass storage API > > it should be impossible to delete things without physical access to the > > pi. > > Before I start reinventing the wheel, does anyone know of anything > > similar to this already in existence? > > Things like chattr don't achieve what I want as root can still override > > that. I'm looking for something that requires physical access to delete. signature.asc Description: OpenPGP digital signature
Re: sources.list 's security line
I use de 2n one with no problems. My sources.list: deb http://security.debian.org/ stable-security main non-free contrib deb http://security.debian.org/ oldstable/updates main non-free contrib Since in http://security.debian.org/dists/stable-security/ there is non-free floder, I keep it in my sources.list Regards, Toni Mas GPG 3F42A21D84D7E950 Sent with ProtonMail Secure Email. ‐‐‐ Original Message ‐‐‐ El dilluns, 6 de setembre 2021 a les 12:42, Brian va escriure: > On Mon 06 Sep 2021 at 06:53:25 -0300, riveravaldez wrote: > > > Hi, > > > > after reading the various sources of documentation (handbook, > > > > wiki, FAQs, Release Notes, etc.) I think I'm finding myself with > > > > kinda four options for the security line in /etc/apt/sources.list > > > > Those being: > > > > deb http://security.debian.org/debian-security bullseye-security main > > > > deb http://security.debian.org bullseye-security main > > > > deb https://deb.debian.org/debian-security bullseye-security main > > > > deb http://security.debian.org testing/updates main > > The first and the third are legitimate lines. I am unsure about the > > other two, particulary the last one. > > > > Brian. signature.asc Description: OpenPGP digital signature
Re: kernel: perf: interrupt took too long
This is usual on my machine after reboot. It could be an alert if after some time doing same work you see this message again. https://bbs.archlinux.org/viewtopic.php?id=187636 Toni Mas GPG 3F42A21D84D7E950 Sent with ProtonMail Secure Email. ‐‐‐ Original Message ‐‐‐ En dimarts 25 de maig de 2021 a les 11:17, john doe va escriure: > On 5/24/2021 5:55 AM, Richard Hector wrote: > > > Hi all, > > I see messages like this frequently for a day or two after rebooting a > > particularly slow old machine (Atom-based HP thin client, running as an > > OpenVPN endpoint): > > May 23 05:36:37 ovpn kernel: [14268.392418] perf: interrupt took too > > long (4020 > 3996), lowering kernel.perf_event_max_sample_rate to 49750 > > Would it be a good idea to set this value at boot time, rather than > > waiting for it to auto-adjust down till it settles? > > Actually I don't know if it's because the machine is slow; it's just the > > only machine I see this on. > > At the time I've looked at this, I came to the conclusion that a cure > was worse than the illness. > > > > John Doe signature.asc Description: OpenPGP digital signature
Re: rsync to NAS for backup
Is there an alternative if you want an incremental backup? Obviously you could use tar-ed archives with unprivileged permissions. If you did, you would get a huge network overhead. thks Toni Mas GPG 3F42A21D84D7E950 Sent with ProtonMail Secure Email. ‐‐‐ Original Message ‐‐‐ En dissabte 13 de febrer de 2021 a les 13:50, didier gaumet va escriure: > Hello, > > Disclaimer: I do not use and am not familiar with Sinology hardware and > software and generally speaking, I am not knowledgeable in networking > > I would say that: > > - the owner:group names of a file on the PC you backup and the > owner:group names of the backup files on the synology files might be > different, even if you try to maintain ownership and rights. What really > counts here are owner:group identifiers (UID:GID). Bob_user:Bob_group on > your PC might equate to Alice_user:John_group on your NAS. Upon > restoration that would be reversed to Bob_user:Bob_group. > That would be typical without something like a LDAP server. > > - SSH root login seems to be discouraged for security reasons. Sinology > probably adhere to this principle and the appropriate way to do what you > want would probably be to access a shell on the Synology software to > issue a sudo or su -c command. > > - editing /etc/sudoers is generally done via the visudo command > - if that is of interest to you, there is a way to install Debian in > chroot on your NAS > signature.asc Description: OpenPGP digital signature
Re: Allow only selected USB
Alternatively, if you run udev, you can add new rule.
Fixed: /etc/udev/rules.d
Volatile: /run/udev/rules.d
I believe this example is autoexplained:
8 # Do not use this rule if I'm not a USB
9 SUBSYSTEM!="usb", GOTO="usbgend"
10 # Only verify on plugin
11 ACTION=="remove", GOTO="usbgend"
12
13 # Select what you want accept by one attributes
22 SUBSYSTEM=="usb", ACTION=="add", ATTRS{manufacturer}=="PixArt",
ATTRS{product}=="USB Optical Mouse", \
23 ATTRS{idVendor}=="0AEa", ATTRS{idProduct}=="2EE0",
ATTRS{bDeviceClass}=="00", ATTR{authorized}="1", GOTO="usbgend"
24
25 # Select what you want accept by other attributes
30 ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="0124",
ATTRS{idProduct}=="4312", ATTR{authorized}="1", GOTO="usbgend"
31
35 # Deactivate other USBs
36 SUBSYSTEM=="usb", ACTION=="add", ATTR{authorized}="0"
37
38 LABEL="usbgend"
Regards,
Toni Mas
GPG 3F42A21D84D7E950
Sent with ProtonMail Secure Email.
‐‐‐ Original Message ‐‐‐
En dimarts 9 de febrer de 2021 a les 23:31, Bhasker C V
va escriure:
> Fantastic ! thanks a ton ! thanks ! exactly what i was looking for
>
> On Tue, Feb 9, 2021 at 7:43 PM wrote:
>
> > Hi,
> >
> > 9 févr. 2021, 19:44 de mailingl...@darac.org.uk:
> >
> > > Certainly. > https://www.kernel.org/doc/html/latest/usb/authorization.html
> > >
> > + https://usbguard.github.io based on it.
> >
> > Best regards,
> > l0f4r0
signature.asc
Description: OpenPGP digital signature
Re: RAID installation at boot questions
I have more or less the same configuration. I am a no-systemd user (yet?) so I cannot show you the full example. You could verify: - Is there a mdraid1x module in your grub menu entry? - If I not wrong you made your RAID by mdadm metadata version 1.2. I think in this version metadata is located at first blocks, on the other hand, version 1.0 places at the end blocks. Somewhere out there I read blootable partitions could not use 1.2 metadata version. Thus, for a bootable (and EFI, if exists) partition must be build in metadata version 1.0. I did and it works. This you could solve your problem. To force a specific metadata version, I used: mdadm --create --metadata=1.0 --verbose /dev/md2 Toni Mas Missatge de Charles Curley del dia ds., 14 de nov. 2020 a les 20:40: > > On Sat, 14 Nov 2020 08:12:41 +0100 > john doe wrote: > > > > > > > What do I do to automate that? > > > > > > > > > > > Is your '/etc/crypttab' file properly populated? > > Well, I thought it was > > At first I got the UUID for the RAID device, /dev/md0: > > root@hawk:~# mdadm --detail /dev/md0 > /dev/md0: >Version : 1.2 > Creation Time : Thu Nov 12 12:06:28 2020 > Raid Level : raid1 > Array Size : 3906884416 (3725.90 GiB 4000.65 GB) > Used Dev Size : 3906884416 (3725.90 GiB 4000.65 GB) > Raid Devices : 2 > Total Devices : 2 >Persistence : Superblock is persistent > > Intent Bitmap : Internal > >Update Time : Sat Nov 14 11:52:39 2020 > State : clean > Active Devices : 2 >Working Devices : 2 > Failed Devices : 0 > Spare Devices : 0 > > Consistency Policy : bitmap > > Name : hawk:0 (local to host hawk) > UUID : 0d3ec9c1:2bc5b3e8:24a27283:c0cad01b > Events : 12270 > > Number Major Minor RaidDevice State >0 8 330 active sync /dev/sdc1 >1 8 491 active sync /dev/sdd1 > root@hawk:~# > > and set that up as a line in /etc/crypttab: > > encryptedRaid UUID=0d3ec9c1-2bc5-b3e8-24a2-7283c0cad01b none luks > > Didn't work, and gave a 90 second timeout. > > Note that the UUID in crypttab is re-formatted to agree with the other > UUIDs in that file, dashes rather than colons. Is that relevant? > > Or (afterthought here) did I give it the wrong UUID? > > root@hawk:~# ll /dev/disk/by-uuid/ > total 0 > drwxr-xr-x 2 root root 300 Nov 14 11:52 ./ > drwxr-xr-x 8 root root 160 Nov 14 11:51 ../ > lrwxrwxrwx 1 root root 10 Nov 14 11:52 343ed59e-ae41-4733-8277-f1b77de67479 > -> ../../sda5 > lrwxrwxrwx 1 root root 10 Nov 14 11:52 52be92ca-795f-46ef-9c52-074fceedc53c > -> ../../dm-1 > lrwxrwxrwx 1 root root 9 Nov 14 11:52 57de8169-da6c-4952-b6ac-25e6c87dbf1a > -> ../../md0 > ... > root@hawk:~# > > Anyway, I tried it by device name, and that worked. > > encryptedRaid /dev/md0 none luks > > Useful tip: that worked without a prompt because I gave /dev/md0's > encryption the same passphrase I gave the other encrypted partitions. > > This also works: > > encryptedRaid /dev/md0 /root/raid.encrypt.password.txt luks > > > -- > Does anybody read signatures any more? > > https://charlescurley.com > https://charlescurley.com/blog/ >
Re: ssh session times out annoyingly fast, why?
First, you should be sure it is not a network issue. You could open a terminal and run, for example, top program. This avoid any timeout configured. If this does not work, you should follow for a network issue, otherwise we can see sshd's config file. Toni Mas Missatge de Britton Kerin del dia dt., 22 de set. 2020 a les 1:38: > > I'm using ssh from a debian box to a rasberry pi (sorta debian also :). > > For some reason ssh sessions seem to time out pretty quickly. I've > tried setting ClientAliveInterval and ClientAliveCountMax and also > ServerAliveInterval and ServerAliveCountMax, but it doesn't seem to > make any difference. Is there some other setting somewhere that > affects this? > > Thanks, > Britton >
Re: Question on 'dpkg --get-selections'
I do this job using aptitude instead apt: /usr/bin/aptitude search '~i !~M' -F '%p' --disable-columns Toni Mas Missatge de Sven Joachim del dia ds., 12 de set. 2020 a les 9:29: > > On 2020-09-11 22:03 -0700, Marc Shapiro wrote: > > > Is there any option to have 'dpkg --get-selections' NOT include > > automatically installed packages? > > No, dpkg has no notion of automatically installed packages, that is an > apt concept. > > > Otherwise, all packages show as manually installed, including those > > that would otherwise have been automatically installed. > > You can obtain a list of automatically installed packages with > apt-mark(1): > > $ apt-mark showauto > automatically-installed-packages > > Then, on the replicated system where you presumably had used > "dpkg --set-selections" to install the same set of packages: > > # apt-mark auto $(cat automatically-installed-packages) > > HTH, > Sven >
Re: add 2FA to ssh
I think 2FA first is better. Thus you don't have to type your password if you have a wrong 2FA. Toni Mas Missatge de Pòl Hallen del dia dj., 13 d’ag. 2020 a les 13:38: > > Hi folks :) > > > what it better with 2FA: at ssh login request first 2FA authentication > next ssh password or viceversa? > > thanks! > > Pol >
Re: copy/paste in vim (in terminal)
Open your file using vi -C <> That works fine for me. Then you can alias vi as vi -C using "alias vi='vi -C'" Toni Mas Missatge de Greg Wooledge del dia dt., 11 d’ag. 2020 a les 13:57: > > On Tue, Aug 11, 2020 at 09:05:06AM +0200, Miguel A. Vallejo wrote: > > Richard Hector () wrote > > > > I used to be able to use my mouse to select/paste 'normally' (for X), > > > when using vim in a terminal. More recently (a few years?), it doesn't > > > seem to work. > > > > Yes, since a few years(?) you must use shift and the mouse for copy / paste > > in vim using Debian's default configuration. > > This changed in stretch, and I've documented it on the wiki, although I > was a bit late in doing so. > > https://wiki.debian.org/NewInStretch#Changes >
Re: Buster without systemd?
I did. I just did not use "full-upgrade" option. I upgraded package by package resolving all dependencies and I had to install elogind but it is not needed to start X system. It was just for dependencies. Please, could you explain the race of conditions risk race? Thanks. Toni Mas Missatge de Renato Gallo del dia dl., 23 de març 2020 a les 9:06: > > > linux without systemd = race condition risks = why in hell anyone would want > to do it ? > > - Messaggio originale - > Da: "Felix Miata" > A: "debian-user" > Inviato: Lunedì, 23 marzo 2020 8:08:28 > Oggetto: Re: Buster without systemd? > > Marc Shapiro composed on 2020-03-22 18:21 (UTC-0700): > > > after 21 to 22 years of using > > Debian (since Bo), do I have to switch to another linux distro? > > AFAIK, no one has ever died as a consequence of using an OS with systemd. So, > no, > you don't "have to" switch to another distro. You can do as most have done, > fondly > or not so fondly remember sysvinit, and accept the change, whether for better > or > worse. > > OTOH, would switching to Devuan really be "switching" to another distro? > That's > like "switching" to any of the zillion distros based on Debian that include > Debian > repos in sources.list. They're mostly Debian but with different defaults, > different far more the interface than the guts that make Debian debian. > -- > Evolution as taught in public schools is religion, not science. > > Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! > > Felix Miata *** http://fm.no-ip.com/ >
Re: hdd partition alignment parted vs fdisk, partition 1 does not start on physical sector boundary, parted bug?
I could be an offset defined. Could you post following files? /sys/block/sdd/queue/optimal_io_size /sys/block/sdd/queue/minimum_io_size /sys/block/sdd/alignment_offset /sys/block/sdd/queue/physical_block_size /sys/block/sdd/queue/logical_block_size Toni Mas Missatge de Sergey Spiridonov del dia dc., 4 de des. 2019 a les 13:30: > > Hi all > > I am trying to partition 14TB HDD and get the following problem with an > alignment: > > # hdparam -I /dev/sdd tells that > > Logical Sector size: 512 bytes > Physical Sector size: 4096 bytes > > > # parted -a opt /dev/sdd > > (parted) mkpart primary 0% 100% > ... > > (parted) print > > Number Start End SizeFile system Name Flags > 1 33,6MB 14,0TB 14,0TB primary > > Now checking alignment: > > (parted) align-check opt > 1 1 aligned > > > So far, so good. Now let's look at the same disk with fdisk: > > # fdisk /dev/sdd > > : p > > Disk /dev/sdd: 12,8 TiB, 14000519643136 bytes, 27344764928 sectors > Disk model: IB-366StU3+B > Units: sectors of 1 * 512 = 512 bytes > Sector size (logical/physical): 512 bytes / 4096 bytes > I/O size (minimum/optimal): 4096 bytes / 33553920 bytes > Disklabel type: gpt > Disk identifier: 82DD924B-BF0E-40FF-9037-1FD4E7307D26 > > Device Start End Sectors Size Type > /dev/sdd1 65535 27344740889 27344675355 12,8T Linux filesystem > > Partition 1 does not start on physical sector boundary. > > > What? Why? > > > man parted tells that > >optimal > Use optimum alignment as given by the disk > topology in‐ formation. This aligns to a > multiple of the physical block size in a way that > guarantees optimal performance > > > 1. Probably parted detected physical sector size as 512 > instead of 4096? Why? > > 2. Even if parted thinks that physical sector is 512 instead of > 4096, why start from 65535 and not from 65536? What is the logic > behind? How using odd multiplier can improve performance? > > Is it a bug in parted or I am missing something? > -- > Best regards, Sergey Spiridonov > > >
Re: apt pinning: find out from which system version is a package
apt-show-versions script are useful as well. apt-show-versions is a package itself. Toni Mas Missatge de Francisco M Neto del dia dl., 29 d’abr. 2019 a les 23:10: > > Greetings! > > > On Mon, 2019-04-29 at 05:30 +0200, Emanuel Berg wrote: > > But is there a way to find out/confirm from > > which release is a certain pack? > > You're looking for apt-cache policy. > > Example: > > == > > $ apt-cache policy gnome-core > gnome-core: > Installed: 1:3.30+1 > Candidate: 1:3.30+1 > Version table: > *** 1:3.30+1 900 > 900 http://sft.if.usp.br/debian buster/main amd64 Packages > 800 http://sft.if.usp.br/debian sid/main amd64 Packages > 100 /var/lib/dpkg/status > 1:3.22+3 400 > 400 http://sft.if.usp.br/debian stretch/main amd64 Packages > > == > > > -- > []'s, > > Francisco M Neto > > GPG: 4096R/D692FBF0
Re: USB hard drives -- recommendations?
I bought "Seagate Expansion STEA3000400" to plug in to a Raspberry PI 3. It don't need extra power suply. I use to backup my data. Toni Mas Missatge de local10 del dia dg., 3 de febr. 2019 a les 1:20: > On 1/25/19 9:24 AM, James H. H. Lampert wrote: > > >> Fellow List members: > >> > >> Would anybody care to voice an opinion on USB external hard drives in > the 2 terabyte size range, for automated backup purposes? > >> > > > You may want to consider buying an USB HDD enclosure/cradle, like this > one[1] for example, they are cheap and would allow you to use a regular > internal HDD as a USB drive. I use similar scheme for my own backups, it > works reasonably well. > > Regards, > > > [1] - https://www.ebay.com/itm/253631205544 < > https://www.ebay.com/itm/253631205544> > >
Re: gnats user
I removed it yesterday, too. No problems at the moment. Toni Mas 2018-03-07 20:13 GMT+01:00 : > On Wednesday, March 07, 2018 01:16:06 AM Reco wrote: > > Along with other uid<100 users, 'gnats' is there for a long time, > > nobody's sure what will break if it's removed from passwd(5), > > Wow! (I am not the OP, but that is disappointing (but not surprising, I > suspect the same or similar about other things buried in Linux one place or > another) and scary. > > > and it's > > not that someone will use uid=41 for anything else. > >
Re: Q: RAID1 and chunk size
I think it has no mean in RAID1 mode. It is used in RAID0,4,5,6,10 modes. You can see in man mdadm. Toni Mas 2018-03-07 23:06 GMT+01:00 Darac Marjal : > > > On 07/03/18 21:13, Steve Keller wrote: > > I have a RAID1 array with 2 disks (/dev/sda1 and /dev/sdb1) of 2 TB > > each. By running mdadm -X /dev/sda1 I see that the chunk size is 64 MB: > > > > # mdadm -X /dev/sda1 > > Filename : /dev/sda1 > > Magic : 6d746962 > > Version : 4 > > UUID : 300551ed:f6690dfb:1c939898:af5509c6 > > Events : 257 > > Events Cleared : 257 > > State : OK > > Chunksize : 64 MB > > Daemon : 5s flush period > > Write Mode : Normal > > Sync Size : 1953381376 (1862.89 GiB 2000.26 GB) > > Bitmap : 29807 bits (chunks), 2 dirty (0.0%) > > > > What exactly does the chunk sized mean? My question is how reads and > > writes on an array are done. Will the kernel always read or write a > > complete chunk? If so, does that mean that writing a single 4 KB > > block to a file system will cause a 64 MB read, i.e one chunk, change > > the 4 KB block in that chunk and write back the 64 MB chunk? > > Yes, my understanding is that chunk size is the size of area upon which > parity is calculated, or the size of data which is allocated before > moving onto the next drive etc. > > My guess, though, is that there is a balance to be struck. Yes, if the > chunk size is small, then there is very little write amplification. But > if the chunk size is too small, then you need to wait for that chunk to > pass the read-write head again, you need to be switching between sectors > very often etc. With a bigger chunk, you can take better advantage of > caching. These days, 64Mb is a relatively small amount to pull into a > buffer, it can be pulled in, modified and rewritten virtually > instantanously. > > There's a nice article on the effect of different chunk sizes here: > http://louwrentius.com/linux-raid-level-and-chunk-size-the-benchmarks.html > > > > > Wouldn't that mean a massive performance problem? > > > > Steve > > > > >
