Overview

StorNext (formerly known as CentraVision File System, or cvfs) is the file system used for the both the blockpool and customer data landing zone on all models of the DXi. However, there are differences between implementations on the various DXi platforms.

Most DXi platforms uses a single StorNext File System named "vol0." When looking at the "df" output on a system, it appears as follows:

[root@SES6702DXi55 ~]# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda6             36569936  12642392  22039912  37% /
/dev/sda5             36569936   2868932  31813372   9% /var
/dev/sda2            125926272  15976776 103449600  14% /scratch
/dev/sda1              1019208     40440    926160   5% /boot
tmpfs                 30798864        12  30798852   1% /dev/shm
/dev/ram0                15863      1122     13922   8% /mnt/rd0
/dev/cvfsctl1_vol0   23671504640 12321147712 11350356928  53% /snfs
qfs                  23671504640 12293337152 11378167488  52% /Q

In this case, the cvfs file system, vol0, is mounted on /snfs. This means that both the customer data and blockpool reside in the same file system.

The DXi8500 and DXi6800 platforms, however, use two distinct StorNext File Systems. One exclusively for customer data called "bulkdata," and the other exclusively for the blockpool called, appropriately enough, "blockpool." When looking at the "df" output on this system, it appears as follows:

 

[root@SES8500DXi51 ~]# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda6             36569936  12253884  22428420  36% /
/dev/sda5             36569936   1734452  32947852   6% /var
/dev/sda2            125926272  54736048  64690328  46% /scratch
/dev/sda1              1019208     42104    924496   5% /boot
tmpfs                 32857068   2677952  30179116   9% /dev/shm
/dev/ram0                15863      1160     13884   8% /mnt/rd0
/dev/cvfsctl1_bulkdata
                     39049374720 1606246912 37443127808   5% /snfs
/dev/cvfsctl2_blockpool
                     1141825024  25874432 1115950592   3% /bp
qfs                  39049374720 1606246912 37443127808   5% /Q

 

Note the two cvfs file systems: bulkdata mounted on /snfs containing the customer data, and blockpool mounted on /bp, containing only the blockpool data. Also note that the /Q file system is tied to the /snfs file system, where customer data resides.

 

Why This Matters

On the DXi8500 and DXi6800 platforms, there are two file system configuration files (/usr/cvfs/config/bulkdata.cfg and /usr/cvfs/config/blockpool.cfg), two file systems that need to be up for the DXi to function properly, and two potential sources for corruption after power outages, etc. When running cvfsck -nv and snapMD.pl scripts to collect information for escalation, particular care needs to be taken to make sure the proper file system is checked and metadata gathered from.

Also, most StorNext File System-related PTR's and troubleshooting information are written for the more prevalent "vol0" file system. If you are having trouble locating the /usr/cvfs/config/vol0.cfg file on the DXi system, chances are you need to be looking for bulkdata.cfg or blockpool.cfg.

If either the bulkdata or blockpool file system fills up, the entire system goes into low space mode. Once again, special care needs to be taken to ensure you are troubleshooting and working on the correct file system before performing any actions.