On 05/03/2012 02:23 PM, aurfalien wrote:
On May 3, 2012, at 2:11 PM, Florian Philipp wrote:
Am 03.05.2012 20:01, schrieb aurfalien:
Hi all,
I never really paid attention to this but a file on an NFS mount is
showing 64M in size, but when copying the file to a local drive, it
shows 2.5MB in size.
My NFS server is hardware Raided with a volume stripe size of 128K
were the volume size is 20TB, my local disk is about 500GB.
Is this due to my stripe size?
Nuggets are appreciated.
- aurf
Is it a sparse file? What exact command did you use to calculate the
file size?
Regards,
Florian Philipp
By the way, this is only across NFS as when ssh'd into the server, the file
size shows 2.5M, same as the clients when its local so its seems NFS is the
culprit.
I have r/wsize tweaked but thats it.
Any ideas?
- aurf
RHEL 5 and 6 'cp' utility enables 'crude heuristic' sparse file detection ('man
ls'). compare results with:
cp --sparse=never /nfsserver/file var/tmp/
and without the --sparse option.
the 'stat' utility is also handy to compare actual disk blocks used vs byte
size. Most filesytems default to 4 KB or eight 512-byte blocks.
'ls -sl' also shows disk blocks (usually in KB, not 'filesystem blocks') used
in first column of output.
NFS options or RAID block size won't matter here, but the NFS file server's
*filesystem* block size can make a difference of how many disk blocks are
actually used on the disk (local or remote). E.g., one of our NFS servers has
a 32K filesystem block size. A one-byte file takes 32K of disk space on that
box.
