I'm trying to run boinc-client on an Raspberry Pi (ARM).

This system has been completely built from the source code, including boinc. I have not used a distribution because they all want to run from SDHC, whereas my system runs completely from RAM disk. My system boots from an SDHC, but then the filesystem is part of the kernel (initramfs), and after the system has finished booting, everything is left running from RAM disk. The SDHC is not touched at all after reading the kernel image.

So far so good.

My problem is boinc-client doesn't think I have any free disk space. e.g.

14-Sep-2013 18:45:38 [---] Starting BOINC client version 7.2.7 for arm-android-linux-gnu
14-Sep-2013 18:45:38 [---] log flags: file_xfer, sched_ops, task
14-Sep-2013 18:45:38 [---] Libraries: libcurl/7.28.1
14-Sep-2013 18:45:38 [---] Running as a daemon
14-Sep-2013 18:45:38 [---] Data directory: /var/lib/boinc
14-Sep-2013 18:45:38 [---] Processor: 1 ARM ARMv6-compatible processor rev 7 (v6l)
14-Sep-2013 18:45:38 [---] Processor features: swp half thumb fastmult vfp edsp java tls
14-Sep-2013 18:45:38 [---] OS: Linux: 3.6.11
14-Sep-2013 18:45:38 [---] Memory: 485.84 MB physical, 0 bytes virtual
14-Sep-2013 18:45:38 [---] Disk: 0 bytes total, 0 bytes free
14-Sep-2013 18:45:38 [---] Local time is UTC +1 hours

Looking at the code, lib/filesys.cpp calls

int retval = STATFS(path, &fs_info);

STATFS in this case is statvfs. The only variable containing data after this call is f_frsize=4096.

Reading up on statvfs I note the comment ...

It is unspecified whether all members of the returned struct have mean‐
ingful values on all file systems.

So I find myself wondering if my initramfs type thing isn't supported.

Some details of my file system (Note that the root fs doesn't appear under the df command - but it is mounted)

# df
Filesystem Size Used Avail Use% Mounted on
devtmpfs 228M 0 228M 0% /dev
tmpfs 243M 0 243M 0% /dev/shm
tmpfs 243M 196K 243M 1% /tmp
# cat /proc/mounts
rootfs / rootfs rw,relatime 0 0
devtmpfs /dev devtmpfs rw,relatime,size=232776k,nr_inodes=58194,mode=755 0 0
proc /proc proc rw,relatime 0 0
devpts /dev/pts devpts rw,relatime,gid=5,mode=620 0 0
tmpfs /dev/shm tmpfs rw,relatime,mode=777 0 0
tmpfs /tmp tmpfs rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0

I admit I've only got limited space on this file system because of the memory constraints, but I should be able to download work 2Mb work units.

# free
total used free shared buffers
Mem: 497504 76216 421288 0 0
-/+ buffers: 76216 421288
Swap: 0 0 0
# dd if=/dev/zero of=file.tmp bs=1k count=200000
200000+0 records in
200000+0 records out
204800000 bytes (205 MB) copied, 2.89176 s, 70.8 MB/s
# free
total used free shared buffers
Mem: 497504 276352 221152 0 0
-/+ buffers: 276352 221152
Swap: 0 0 0

I acknowledge I could just plug some numbers into free_space and total_space in get_filesystem_info(), but is there a better way ?

Anyone got any experience of this sort of thing ?

I think this is one of those questions that you better, in its entirety send to the BOINC Development email list. http://lists.ssl.berkeley.edu/mailman/listinfo/boinc_dev
It does require registration.

---

OK

Reading Documentation/filesystems/ramfs-rootfs-initramfs.txt it sounds like rootfs is a very special and minimal filesystem, perhaps that's why it doesn't work.

You could try mounting tmpfs to /var/lib/boinc. At least tmpfs is listed in df output.