Question on disk size and usage


 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers Question on disk size and usage
# 1  
Old 03-10-2014
Question on disk size and usage

Hello All, this may be a simple question but I wasn't sure how to word it to search for the answer. Have a look at the following:
Code:
/dev/mapper/vgdata-lvdata             626G  594G     0 100% /data01

As you can see the disk size 626GB of which 594G is used. There's 32GB difference there but the system shows amount available is 0 and 100% full. This is a RedHat 5 system and the filesystems are ext3.

1. Why is so much of the disk being wasted?
2. How can I fix it so more of the disk is actually used and not wasted?

Last edited by vbe; 03-10-2014 at 10:50 AM..
# 2  
Old 03-10-2014
You are talking of a around 5% reserved space, 5% isnt much you know...
That is a minimum for root to be able to access once full to guarantee possible cleanups and reorg...
# 3  
Old 03-10-2014
1. As vbe said 5% is not that much and when filesystems were smaller because disks were not the size they have today 5% was a reasonable choice.
2. You can reduce the reserved space with tune2fs to, for example 1%.
Code:
tune2fs -m 1 /dev/mapper/vgdata-lvdata

Edit: do not tune your root filesystem this way - there those 5% may save your job some day...
# 4  
Old 03-10-2014
Personally, I would leave the filesytem overhead to the OS default.

You need to look at clearing space more than anything. Be aware that your server may hang and may not complete the boot with such a full root filesystem.
  • Are you LVM? That gives us more options to consider, but as a first pass:-
  • What other filesystems do you have in the root volume group?
  • Are /opt, /tmp, /var & /usr separate filesystems?
  • Do you have any space left in the root volume group (whatever it's called)?
  • Can you show us the output from:-
    Code:
    vgdisplay

    then
    Code:
    vgdisplay -v <root_volume_group>

I've just spent a few hours of down-time to shrink and split our root filesystem to reduce the risk of:-
  • Someone creating a huge file in /tmp that fills the root filesystem.
  • A process looping and generating messages to the syslog (usually in /var) and filling the root filesystem
...so it can be done, but it's a bit messy.

You could also have a look at the output from:-
Code:
du -kx|sort -n

and explore where your space is consumed.



Thanks, in advance,
Robin
# 5  
Old 03-20-2014
Thank you for the replies. I have a better understanding now. I know where the space is going and I can easily add more disks to the LV. I was just wondering about the space being "wasted" (which its not).

Thanks again.
# 6  
Old 03-20-2014
Quote:
Originally Posted by bbbngowc
Thank you for the replies. I have a better understanding now. I know where the space is going and I can easily add more disks to the LV. I was just wondering about the space being "wasted" (which its not).

Thanks again.
Definitely not a waste. A completely full root disk can cause major, difficult-to-solve problems, to the point you can't run rm and people can't login. That you're not having problems like that right now means the reserved space is doing its job Smilie
 
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

Disk usage monitoring and record the disk used in last 24 hour

HI I am Trying to edit the below code to send email every day with difference of disk utilized in for last 24 hours but instead getting same usage everyday. can you please help me to point out where my calculation is going wrong. Thank you. ================= #!/bin/bash TODAY="at $(date... (0 Replies)
Discussion started by: Mi4304
0 Replies

2. UNIX for Advanced & Expert Users

Physical disk IO size smaller than fragment block filesystem size ?

Hello, in one default UFS filesystem we have 8K block size (bsize) and 1K fragmentsize (fsize). At this scenary I thought all "FileSytem IO" will be 8K (or greater) but never smaller than the fragment size (1K). If a UFS fragment/blocksize is allwasy several ADJACENTS sectors on disk (in a ... (4 Replies)
Discussion started by: rarino2
4 Replies

3. HP-UX

Disk Usage

Hi Experts, glance is showing disk util 100% on of production domain and while collecting sar data using sar -d 5 5, avserv for some of the disks are more than 10 miliseconds. Need your advise on steps that needs to be taken to reduce the disk utilitzation. device %busy avque r+w/s ... (2 Replies)
Discussion started by: sai_2507
2 Replies

4. Solaris

current CPU usage, memory usage, disk I/O oid(snmp)

Hi, I want to monitor the current cpu usage, monitor usage , disk I/o and network utlization for solaris using SNMP. I want the oids for above tasks. can you please tell me that Thank you (2 Replies)
Discussion started by: S_venkatesh
2 Replies

5. HP-UX

how can I find cpu usage memory usage swap usage and logical volume usage

how can I find cpu usage memory usage swap usage and I want to know CPU usage above X% and contiue Y times and memory usage above X % and contiue Y times my final destination is monitor process logical volume usage above X % and number of Logical voluage above can I not to... (3 Replies)
Discussion started by: alert0919
3 Replies

6. Shell Programming and Scripting

disk usage

fdisk -l shows me the total disk size. How can I see, how much disk space is free or available? (5 Replies)
Discussion started by: tjay83
5 Replies

7. Shell Programming and Scripting

Disk Usage

Hi, I want to retrieve the directory in the shell script that is using maximum space on the disk.I was using du command but it displays all the directories that are using the space on the disk.How can retrieve the only directory which uses the maximum space on the disk?? Thanks in advance. ... (4 Replies)
Discussion started by: harikamamidala
4 Replies

8. Shell Programming and Scripting

disk usage

Hi ,.. I am working on a script like.... it has to monitor the disk usage (df -H) and if usage is above 95% then it has to return the particular mount point details... i am in confusion to use awk or sed..... regards rrs (1 Reply)
Discussion started by: rrs
1 Replies

9. AIX

basic question about disk usage

how to i find out the disk usage on a server. say in windows examples its like C:/ D:/ and checking out the disk space. how can i find in Unix. can i just use df -k (3 Replies)
Discussion started by: karthikosu
3 Replies

10. UNIX for Dummies Questions & Answers

disk usage

what are the ways to check the disc usage by users. I mean to say how to find the biggest space consumer. Regards. (4 Replies)
Discussion started by: asutoshch
4 Replies
Login or Register to Ask a Question