Re: non-persistent storage?
On Dec 17 09:32, Andrey Repin wrote: > Greetings, Ulli Horlacher! > > > /dev/shm ist not a tmpfs on cygwin: > > Cygwin is a userspace DLL. It is not a filesystem driver. > > > /dev/shm: df -TH /dev/shm > > Filesystem Type Size Used Avail Use% Mounted on > > C:/cygwin64ntfs 34G 25G 9.1G 74% / > > > When I write something into this direcory and reboot, it is still there. > > Use iSCSI RAM disk? > http://woshub.com/create-ram-disk-windows-server/ Great idea! Pity this only works on server machines. Corinna -- Corinna Vinschen Cygwin Maintainer signature.asc Description: PGP signature
Re: non-persistent storage?
Greetings, Ulli Horlacher! > /dev/shm ist not a tmpfs on cygwin: Cygwin is a userspace DLL. It is not a filesystem driver. > /dev/shm: df -TH /dev/shm > Filesystem Type Size Used Avail Use% Mounted on > C:/cygwin64ntfs 34G 25G 9.1G 74% / > When I write something into this direcory and reboot, it is still there. Use iSCSI RAM disk? http://woshub.com/create-ram-disk-windows-server/ -- With best regards, Andrey Repin Tuesday, December 17, 2019 9:29:29 Sorry for my terrible english... -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: non-persistent storage?
On Dec 13 10:34, Ulli Horlacher wrote: > On Fri 2019-12-13 (07:27), Jürgen Wagner wrote: > > And regarding the tmpfs (RAM disk) , you can use /dev/shm. > > > > # date > /dev/shm/key > > # cat /dev/shm/key > > Fri Dec 13 07:26:03 CET 2019 > > /dev/shm ist not a tmpfs on cygwin: > > /dev/shm: df -TH /dev/shm > Filesystem Type Size Used Avail Use% Mounted on > C:/cygwin64ntfs 34G 25G 9.1G 74% / > > When I write something into this direcory and reboot, it is still there. ...unless you open the file with the O_TMPFILE flag as outlined in my other reply. Corinna -- Corinna Vinschen Cygwin Maintainer signature.asc Description: PGP signature
Re: non-persistent storage?
On Fri, 13 Dec 2019 17:57:23 -0500, Erik Soderquist wrote: I've test all of the suggestions I've seen so far with the exception of the cygserver and shared memory, and all of the ones I've tested failed the power failure scenario. /dev/clipboard? -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: non-persistent storage?
On Fri, Dec 13, 2019 at 11:20 AM Buchbinder, Barry (NIH/NIAID) [E] via cygwin wrote: > One could put a script, batch file, or a link thereto in one's startup > folder that will run on Windows' boot. The OP's issue is that the data must be destroyed instantly even in the event of a power failure. Use case scenario: thief breaks in and steals the host, just yanking power cords/etc out, and then pulls the drive and mounts it on another system to recover this data; it is sensitive enough that it must be destroyed immediately by the power failure. Unfortunately, nothing in Windows is designed for that kind of security, and Cygwin has to work around a lot of Windows design flaws to function in general. I've test all of the suggestions I've seen so far with the exception of the cygserver and shared memory, and all of the ones I've tested failed the power failure scenario. I think if the cygserver/shared memory suggestion works, it will be the only available option to prevent the data from default existing on the disc, and due to another of Window's design flaws, may still be written into the page file, though it would be much harder to cleanly extract from the page file than from a normal filesystem file. -- Erik -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: non-persistent storage?
Ulli Horlacher wrote: On Fri 2019-12-13 (00:51), Jürgen Wagner wrote: - Run cygserver-config as an administrator. ~: cygserver-config Generating /etc/cygserver.conf file Warning: The following function requires administrator privileges! Do you want to install cygserver as service? (Say "no" if it's already installed as service) (yes/no) yes /usr/bin/cygserver-config: line 181: cygrunsrv: command not found In addition to Marco's reply for shmtool, you'll need the 'cygrunsrv' package. ..mark -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
RE: non-persistent storage?
>On Thu, Dec 12, 2019 at 5:08 PM Ulli Horlacher wrote: > >>Erik Soderquist sent the following at Thursday, December 12, 2019 5:45 pm >> >> On Thu 2019-12-12 (21:59), Buchbinder, Barry (NIH/NIAID) [E] via cygwin >> wrote: >>> >>> If the temp file was created by mktemp and the name saved in an >>> environmental variable, each bash shell could have its own file with >>> not risk that an instance of bash would erase another instance's file. >> >> I need the opposite: all processes must read and write the same data! >> And the data must be gone when system shuts down or even if there is a >> power failure. > > This is very hacky, but I believe you can get the effect you want by > having an admin process auto-start at host startup, identify itself, and > then set parts of its own /proc/ process ID tree as world read/write. > I think this will give you the "destroyed even at power failure" > impermanence you are looking for. I know it is not in the normal > layouts (like /var/run/ would be), but we are working around limitations > imposed by Windows. One could put a script, batch file, or a link thereto in one's startup folder that will run on Windows' boot. The script/batch file would be written to clean out the tmp files. Google << windows startup folder >>. If all processes, regardless of whether they start with the same shell/subshell, will share the same temp file, one could create the file upon boot using the same script. Also, one could make the script that creates the temp file (e.g., .bashrc) check the file or an environmental variable so that a subshell doesn't create a new temp file, if that's how you want it. - Barry Disclaimer: Statements made herein are not made on behalf of NIAID.
Re: non-persistent storage?
Am 13.12.2019 um 11:06 schrieb Ulli Horlacher: On Fri 2019-12-13 (00:51), Jürgen Wagner wrote: - Run cygserver-config as an administrator. ~: cygserver-config Generating /etc/cygserver.conf file Warning: The following function requires administrator privileges! Do you want to install cygserver as service? (Say "no" if it's already installed as service) (yes/no) yes /usr/bin/cygserver-config: line 181: cygrunsrv: command not found # shmtool w myFunnyC8380ufsKey shmtool is also missing. Which package have I to install? $ cygcheck -p shmtool Found 6 matches for shmtool ... cygutils-extra-1.4.16-2 - cygutils-extra: A collection of simple utilities (other tools) -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: non-persistent storage?
On Fri 2019-12-13 (00:51), Jürgen Wagner wrote: > - Run cygserver-config as an administrator. ~: cygserver-config Generating /etc/cygserver.conf file Warning: The following function requires administrator privileges! Do you want to install cygserver as service? (Say "no" if it's already installed as service) (yes/no) yes /usr/bin/cygserver-config: line 181: cygrunsrv: command not found > # shmtool w myFunnyC8380ufsKey shmtool is also missing. Which package have I to install? -- Ullrich Horlacher Server und Virtualisierung Rechenzentrum TIK Universitaet Stuttgart E-Mail: horlac...@tik.uni-stuttgart.de Allmandring 30aTel:++49-711-68565868 70569 Stuttgart (Germany) WWW:http://www.tik.uni-stuttgart.de/ REF:<72eb3b54-1c86-689e-f663-543f80755...@wagner.is> -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: non-persistent storage?
On Fri 2019-12-13 (07:27), Jürgen Wagner wrote: > And regarding the tmpfs (RAM disk) , you can use /dev/shm. > > # date > /dev/shm/key > # cat /dev/shm/key > Fri Dec 13 07:26:03 CET 2019 /dev/shm ist not a tmpfs on cygwin: /dev/shm: df -TH /dev/shm Filesystem Type Size Used Avail Use% Mounted on C:/cygwin64ntfs 34G 25G 9.1G 74% / When I write something into this direcory and reboot, it is still there. -- Ullrich Horlacher Server und Virtualisierung Rechenzentrum TIK Universitaet Stuttgart E-Mail: horlac...@tik.uni-stuttgart.de Allmandring 30aTel:++49-711-68565868 70569 Stuttgart (Germany) WWW:http://www.tik.uni-stuttgart.de/ REF:<019cfbcf-d1b3-ddf0-1f07-5c2fda599...@wagner.is> -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: non-persistent storage?
And regarding the tmpfs (RAM disk) , you can use /dev/shm. # date > /dev/shm/key # cat /dev/shm/key Fri Dec 13 07:26:03 CET 2019 # It is not advisable to store larger amounts of data there, but an encryption key should be fine. Cheers, --j. On 13.12.2019 00:21, Ulli Horlacher wrote: On Fri 2019-12-13 (00:03), Jürgen Wagner wrote: 1. You create a RAM disk How do I do it with cygwin? 2. You encrypt the data with a ephemeral key This is exactly what I want to share between processes! smime.p7s Description: S/MIME Cryptographic Signature
Re: non-persistent storage?
Ok, we're getting closer. - Run cygserver-config as an administrator. - Do "net start cygserver" That will provide shared memory capabilities. Then try this: # shmtool w myFunnyC8380ufsKey Shared memory segment exists - opening as client Done... # shmtool r Shared memory segment exists - opening as client segptr: myFunnyC8380ufsKey # On reboot of the host Windows, the shared memory segment will not be persisted. Cheers, --j. On 13.12.2019 00:21, Ulli Horlacher wrote: On Fri 2019-12-13 (00:03), Jürgen Wagner wrote: 1. You create a RAM disk How do I do it with cygwin? 2. You encrypt the data with a ephemeral key This is exactly what I want to share between processes! smime.p7s Description: S/MIME Cryptographic Signature
Re: non-persistent storage?
On Fri 2019-12-13 (00:03), Jürgen Wagner wrote: > 1. You create a RAM disk How do I do it with cygwin? > 2. You encrypt the data with a ephemeral key This is exactly what I want to share between processes! -- Ullrich Horlacher Server und Virtualisierung Rechenzentrum TIK Universitaet Stuttgart E-Mail: horlac...@tik.uni-stuttgart.de Allmandring 30aTel:++49-711-68565868 70569 Stuttgart (Germany) WWW:http://www.tik.uni-stuttgart.de/ REF:<3bcb25a9-3d7a-2b88-f2ca-83d46f2b0...@wagner.is> -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: non-persistent storage?
On Thu 2019-12-12 (17:45), Erik Soderquist wrote: > This is very hacky, but I believe you can get the effect you want by > having an admin process auto-start at host startup, identify itself, > and then set parts of its own /proc/ process ID tree as world > read/write. It is not possible to write any data to /proc using standard IO read/write like on a tmpfs file system. -- Ullrich Horlacher Server und Virtualisierung Rechenzentrum TIK Universitaet Stuttgart E-Mail: horlac...@tik.uni-stuttgart.de Allmandring 30aTel:++49-711-68565868 70569 Stuttgart (Germany) WWW:http://www.tik.uni-stuttgart.de/ REF: -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: non-persistent storage?
I can see two options: 1. You create a RAM disk and the contents will obviously be gone when the system reboots or crashes. 2. You encrypt the data with a ephemeral key that will be lost on reboot (e.g., kept in shared memory). When the system comes up and finds itself unable to read the data, it will erase it. That doesn't really have much to do with Cygwin or Windows - you can do that on any system. On 12.12.2019 23:07, Ulli Horlacher wrote: On Thu 2019-12-12 (21:59), Buchbinder, Barry (NIH/NIAID) [E] via cygwin wrote: If the temp file was created by mktemp and the name saved in an environmental variable, each bash shell could have its own file with not risk that an instance of bash would erase another instance's file. I need the opposite: all processes must read and write the same data! And the data must be gone when system shuts down or even if there is a power failure. smime.p7s Description: S/MIME Cryptographic Signature
Re: non-persistent storage?
On Thu, Dec 12, 2019 at 5:45 PM Erik Soderquist wrote: > This is very hacky, but I believe you can get the effect you want by > having an admin process auto-start at host startup, identify itself, > and then set parts of its own /proc/ process ID tree as world > read/write. I think this will give you the "destroyed even at power > failure" impermanence you are l,booking for. I know it is not in the > normal layouts (like /var/run/ would be), but we are working around > limitation s imposed by Windows. To "move"to /var/run/, the process could also build symlinks to the location(s) in /proc/ so the other programs/users have a stable /var/run/ location and only the auto-started process needs to know or care about the locations in /proc/ -- Erik -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: non-persistent storage?
On Thu, Dec 12, 2019 at 5:08 PM Ulli Horlacher wrote: > > On Thu 2019-12-12 (21:59), Buchbinder, Barry (NIH/NIAID) [E] via cygwin wrote: > > > If the temp file was created by mktemp and the name saved in an > > environmental variable, each bash shell could have its own file with not > > risk that an instance of bash would erase another instance's file. > > I need the opposite: all processes must read and write the same data! > And the data must be gone when system shuts down or even if there is a > power failure. This is very hacky, but I believe you can get the effect you want by having an admin process auto-start at host startup, identify itself, and then set parts of its own /proc/ process ID tree as world read/write. I think this will give you the "destroyed even at power failure" impermanence you are l,booking for. I know it is not in the normal layouts (like /var/run/ would be), but we are working around limitation s imposed by Windows. -- Erik -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Re: non-persistent storage?
On Thu 2019-12-12 (21:59), Buchbinder, Barry (NIH/NIAID) [E] via cygwin wrote: > If the temp file was created by mktemp and the name saved in an > environmental variable, each bash shell could have its own file with not > risk that an instance of bash would erase another instance's file. I need the opposite: all processes must read and write the same data! And the data must be gone when system shuts down or even if there is a power failure. -- Ullrich Horlacher Server und Virtualisierung Rechenzentrum TIK Universitaet Stuttgart E-Mail: horlac...@tik.uni-stuttgart.de Allmandring 30aTel:++49-711-68565868 70569 Stuttgart (Germany) WWW:http://www.tik.uni-stuttgart.de/ REF: -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
RE: non-persistent storage?
Eliot Moss sent the following at Thursday, December 12, 2019 2:19 pm >On 12/12/2019 7:00 AM, Ulli Horlacher wrote: > >> I need to store some data (a few kB) non-persistent. >> On a real UNIX I would use /var/run, because after a shutdown all its >> content is lost. >> But on cygwin /var/run is stored on disk. >> >> I cannot use an environment variable, because different processes need >> to read/write the data. >> >> /proc is non-persistent (in respect to a reboot), but It is not a >> generic storage place. >> >> What can I use with cygwin instead? >> >> Installing third party software is not an option, it must work with a >> standard Windows (and cygwin). > >I would think of temp directories, such as /tmp. They can be cleaned out >at will on restart, no? Bash runs the file ~/.bash_logout when it exits. One could use that to clear a temp file out of /tmp. If the temp file was created by mktemp and the name saved in an environmental variable, each bash shell could have its own file with not risk that an instance of bash would erase another instance's file. That assumes that this is consistent with your need for different processes to read/write data. Good luck, - Barry Disclaimer: Statements made herein are not made on behalf of NIAID. -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
