[pbs-devel] [PATCH proxmox-backup v2] etc: provide and enable mount unit for /run/proxmox-backup

[pbs-devel] [PATCH proxmox-backup v2] etc: provide and enable mount unit for /run/proxmox-backup

[Christian Ebner]

Since the introduction of per-chunk file locks for datastores with s3
backend, the inodes on the tmpfs backing /run/proxmox-backup might be
to limited, the kernel dynamically calculating the limit based on
available system memory [0]. To not limit the number of inodes,
provide a systemd mount unit to create a dedicated tmpfs for
/run/proxmox-backup.

The mount unit is only enabled but not started by dh_installsystemd,
so this has only effect after a reboot.

[0] https://docs.kernel.org/filesystems/tmpfs.html

Fixes: https://forum.proxmox.com/threads/176228/
Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
---
Changes since version 1 (thanks @Fabian):
- Drop unneeded systemctl enable ...
- Add comment for why the inodes are unlimited
- Correctly set mountpoint uid:gid

 debian/proxmox-backup-server.install |  1 +
 "etc/run-proxmox\\x2dbackup.mount"   | 14 ++++++++++++++
 2 files changed, 15 insertions(+)
 create mode 100644 "etc/run-proxmox\\x2dbackup.mount"

diff --git a/debian/proxmox-backup-server.install b/debian/proxmox-backup-server.install
index d06f026cf..11dd037e8 100644
--- a/debian/proxmox-backup-server.install
+++ b/debian/proxmox-backup-server.install
@@ -6,6 +6,7 @@ etc/proxmox-backup-daily-update.timer /usr/lib/systemd/system/
 etc/proxmox-backup-proxy.service /usr/lib/systemd/system/
 etc/proxmox-backup.service /usr/lib/systemd/system/
 etc/removable-device-attach@.service /usr/lib/systemd/system/
+etc/run-proxmox\x2dbackup.mount /usr/lib/systemd/system/
 usr/bin/pmt
 usr/bin/pmtx
 usr/bin/proxmox-tape
diff --git "a/etc/run-proxmox\\x2dbackup.mount" "b/etc/run-proxmox\\x2dbackup.mount"
new file mode 100644
index 000000000..cad35594d
--- /dev/null
+++ "b/etc/run-proxmox\\x2dbackup.mount"
@@ -0,0 +1,14 @@
+[Unit]
+Description=Mount tmpfs at /run/proxmox-backup
+Conflicts=umount.target
+Before=local-fs.target umount.target
+
+[Mount]
+Type=tmpfs
+What=tmpfs
+Where=/run/proxmox-backup
+# Unlimited inodes as this stores per-chunk file locks
+Options=rw,nosuid,nodev,noexec,relatime,uid=34,gid=34,nr_inodes=0,mode=755,inode64
+
+[Install]
+WantedBy=local-fs.target
-- 
2.47.3



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Re: [pbs-devel] [PATCH proxmox-backup v2] etc: provide and enable mount unit for /run/proxmox-backup

[Fabian Grünbichler]

On November 19, 2025 3:31 pm, Christian Ebner wrote:
> Since the introduction of per-chunk file locks for datastores with s3
> backend, the inodes on the tmpfs backing /run/proxmox-backup might be
> to limited, the kernel dynamically calculating the limit based on
> available system memory [0]. To not limit the number of inodes,
> provide a systemd mount unit to create a dedicated tmpfs for
> /run/proxmox-backup.
> 
> The mount unit is only enabled but not started by dh_installsystemd,
> so this has only effect after a reboot.
> 
> [0] https://docs.kernel.org/filesystems/tmpfs.html
> 
> Fixes: https://forum.proxmox.com/threads/176228/
> Signed-off-by: Christian Ebner <c.ebner@proxmox.com>

Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

> ---
> Changes since version 1 (thanks @Fabian):
> - Drop unneeded systemctl enable ...
> - Add comment for why the inodes are unlimited
> - Correctly set mountpoint uid:gid
> 
>  debian/proxmox-backup-server.install |  1 +
>  "etc/run-proxmox\\x2dbackup.mount"   | 14 ++++++++++++++
>  2 files changed, 15 insertions(+)
>  create mode 100644 "etc/run-proxmox\\x2dbackup.mount"
> 
> diff --git a/debian/proxmox-backup-server.install b/debian/proxmox-backup-server.install
> index d06f026cf..11dd037e8 100644
> --- a/debian/proxmox-backup-server.install
> +++ b/debian/proxmox-backup-server.install
> @@ -6,6 +6,7 @@ etc/proxmox-backup-daily-update.timer /usr/lib/systemd/system/
>  etc/proxmox-backup-proxy.service /usr/lib/systemd/system/
>  etc/proxmox-backup.service /usr/lib/systemd/system/
>  etc/removable-device-attach@.service /usr/lib/systemd/system/
> +etc/run-proxmox\x2dbackup.mount /usr/lib/systemd/system/
>  usr/bin/pmt
>  usr/bin/pmtx
>  usr/bin/proxmox-tape
> diff --git "a/etc/run-proxmox\\x2dbackup.mount" "b/etc/run-proxmox\\x2dbackup.mount"
> new file mode 100644
> index 000000000..cad35594d
> --- /dev/null
> +++ "b/etc/run-proxmox\\x2dbackup.mount"
> @@ -0,0 +1,14 @@
> +[Unit]
> +Description=Mount tmpfs at /run/proxmox-backup
> +Conflicts=umount.target
> +Before=local-fs.target umount.target
> +
> +[Mount]
> +Type=tmpfs
> +What=tmpfs
> +Where=/run/proxmox-backup
> +# Unlimited inodes as this stores per-chunk file locks
> +Options=rw,nosuid,nodev,noexec,relatime,uid=34,gid=34,nr_inodes=0,mode=755,inode64

one small nit: this could use `backup` instead of `34` (although it's
pretty much guaranteed to not matter, we do so in other parts of the
code base as well..)

> +
> +[Install]
> +WantedBy=local-fs.target
> -- 
> 2.47.3
> 
> 
> 
> _______________________________________________
> pbs-devel mailing list
> pbs-devel@lists.proxmox.com
> https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel
> 
> 
> 


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Re: [pbs-devel] [PATCH proxmox-backup v2] etc: provide and enable mount unit for /run/proxmox-backup

[Christian Ebner]

On 11/20/25 9:05 AM, Fabian Grünbichler wrote:
> On November 19, 2025 3:31 pm, Christian Ebner wrote:
>> Since the introduction of per-chunk file locks for datastores with s3
>> backend, the inodes on the tmpfs backing /run/proxmox-backup might be
>> to limited, the kernel dynamically calculating the limit based on
>> available system memory [0]. To not limit the number of inodes,
>> provide a systemd mount unit to create a dedicated tmpfs for
>> /run/proxmox-backup.
>>
>> The mount unit is only enabled but not started by dh_installsystemd,
>> so this has only effect after a reboot.
>>
>> [0] https://docs.kernel.org/filesystems/tmpfs.html
>>
>> Fixes: https://forum.proxmox.com/threads/176228/
>> Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
> 
> Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
> 
>> ---
>> Changes since version 1 (thanks @Fabian):
>> - Drop unneeded systemctl enable ...
>> - Add comment for why the inodes are unlimited
>> - Correctly set mountpoint uid:gid
>>
>>   debian/proxmox-backup-server.install |  1 +
>>   "etc/run-proxmox\\x2dbackup.mount"   | 14 ++++++++++++++
>>   2 files changed, 15 insertions(+)
>>   create mode 100644 "etc/run-proxmox\\x2dbackup.mount"
>>
>> diff --git a/debian/proxmox-backup-server.install b/debian/proxmox-backup-server.install
>> index d06f026cf..11dd037e8 100644
>> --- a/debian/proxmox-backup-server.install
>> +++ b/debian/proxmox-backup-server.install
>> @@ -6,6 +6,7 @@ etc/proxmox-backup-daily-update.timer /usr/lib/systemd/system/
>>   etc/proxmox-backup-proxy.service /usr/lib/systemd/system/
>>   etc/proxmox-backup.service /usr/lib/systemd/system/
>>   etc/removable-device-attach@.service /usr/lib/systemd/system/
>> +etc/run-proxmox\x2dbackup.mount /usr/lib/systemd/system/
>>   usr/bin/pmt
>>   usr/bin/pmtx
>>   usr/bin/proxmox-tape
>> diff --git "a/etc/run-proxmox\\x2dbackup.mount" "b/etc/run-proxmox\\x2dbackup.mount"
>> new file mode 100644
>> index 000000000..cad35594d
>> --- /dev/null
>> +++ "b/etc/run-proxmox\\x2dbackup.mount"
>> @@ -0,0 +1,14 @@
>> +[Unit]
>> +Description=Mount tmpfs at /run/proxmox-backup
>> +Conflicts=umount.target
>> +Before=local-fs.target umount.target
>> +
>> +[Mount]
>> +Type=tmpfs
>> +What=tmpfs
>> +Where=/run/proxmox-backup
>> +# Unlimited inodes as this stores per-chunk file locks
>> +Options=rw,nosuid,nodev,noexec,relatime,uid=34,gid=34,nr_inodes=0,mode=755,inode64
> 
> one small nit: this could use `backup` instead of `34` (although it's
> pretty much guaranteed to not matter, we do so in other parts of the
> code base as well..)

Okay, will resend with that adapted, thanks!


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[pbs-devel] superseded: [PATCH proxmox-backup v2] etc: provide and enable mount unit for /run/proxmox-backup

[Christian Ebner]

superseded-by version 3:
https://lore.proxmox.com/pbs-devel/20251120100523.12147-1-c.ebner@proxmox.com/T/


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