by Pedro M. S. Oliveira | Mar 17, 2012 | Linux

While tuning and benchmarking an HP backup device (HPD2D backup system) I needed to estimate the average file size of the IMAP server storage.
You may think I could just count the number of files and the divide the used space by the number of files, but that wasn’t the case because I didn’t want all the files to count, in this case I just needed the maildir files that have the email content.
So I did a little script (just a command line) using gawk to do it for me:
find /home/vmail -type f -name [0-9]* -exec ls -l {} \; | gawk '{sum += $5; n++;} END {print sum/n;}'
First I find all the files that starts with a number on the base directory of my dovecot server (IMAP storage), and the I need to list them as the size info is needed.
Second I’ve a little gawk script that will do the sum and division.
Let me say this took a few hours as the storage holding the files has 8TB of data.
Well hope this will help some1 else.
Cheers,
Pedro
by Pedro M. S. Oliveira | Mar 9, 2012 | Linux
Hi!
About a year ago I’ve setup some linux RHEL 6 with multipath access to an HP EVA storage.
Today I needed to do it again, and to do so i needed to list all the path available to the storage device, here’s my command line (hope it helps someone else) to list all the path and volumes:
ls /dev/sd* | grep -E -v '[0-9]' | while read D ; do F=$(echo $D) ; \
echo -n $F ; echo -n " " ; scsi_id --page=0x83 --whitelisted --device=$F | \
sort -k 2 ; done | sort -k 2
The output should be something like this:
/dev/sda 3600508b1001c927a634cedb90322b49e
/dev/sdb 3600508b4000744ff0000a00001fd0000
/dev/sdf 3600508b4000744ff0000a00001fd0000
/dev/sdj 3600508b4000744ff0000a00001fd0000
/dev/sdn 3600508b4000744ff0000a00001fd0000
/dev/sdd 3600508b4000744ff0000a000025c0000
/dev/sdh 3600508b4000744ff0000a000025c0000
/dev/sdl 3600508b4000744ff0000a000025c0000
/dev/sdp 3600508b4000744ff0000a000025c0000
/dev/sde 3600508b4000744ff0000a000025f0000
/dev/sdi 3600508b4000744ff0000a000025f0000
/dev/sdm 3600508b4000744ff0000a000025f0000
/dev/sdq 3600508b4000744ff0000a000025f0000
/dev/sdc 3600508b4000744ff0000a00002660000
/dev/sdg 3600508b4000744ff0000a00002660000
/dev/sdk 3600508b4000744ff0000a00002660000
/dev/sdo 3600508b4000744ff0000a00002660000
As you can see I’ve one available disk on this server, actually this one is a RAID1 (HW) config (sda), 16 paths to my storage device, that delivers 4 different volumes (4 paths to each volume).
Sometime later I’ll discuss the multipath configuration but for now i just wanted to leave the command line that help me list all the paths ids.
Cheers,
Pedro Oliveira