Open System Services Management and Operations Guide (G06.29+, H06.07+)

Managing OSS Files
Open System Services Management and Operations Guide—527191-005
6-22
Backing Up OSS Files to Other Expand Nodes
Figure 6-4 on page 6-22 shows the output of one such DSAP command. The total
number of pages in a fileset on one disk is shown in the Total Pages column for its
subvolume. To determine the total number of bytes, multiply the total pages by
2048 (the number of bytes/page).
In Figure 6-4, the total number of pages for the HOME fileset is shown as 485776.
Multiplied by 2048, the total size of the HOME fileset would be 994,869,248 bytes if
it is completely contained on this one disk. Because this is smaller than the size
limit for pax files, you can back up the HOME fileset in the Guardian file system.
For more information about the DSAP command, see the Guardian Disk and Tape
Utilities Reference Manual.
To create the backup for the OSS files in the HOME fileset as a file in the Guardian file
system, enter the following OSS shell command:
pax -X -wvf /G/oss/backup/paxhome /home
This command creates the pax archive as the Guardian file
$OSS.BACKUP.PAXHOME on the local NonStop server node. The -X flag prevents
the pax utility from descending into directories within /home when those directories
reside in a different fileset (as indicated by the use of a different device ID from that
used for files in /home that are part of the HOME fileset).
If the HOME fileset had been slightly larger than the pax file size limit, the following
OSS shell command might also have succeeded:
pax -X -wv /home | compress > /G/oss/backup/paxhome
The amount of data beyond the limit that can be backed up in this manner depends on
the contents of the files within the fileset.
Backing Up OSS Files to Other Expand Nodes
You can perform a remote backup of OSS files indirectly by using the pax utility and
writing the backup archive to a directory within the Guardian file system (a directory
within/G), where the archive file is a Guardian file. For more information on creating a
backup archive in a /G directory, see Creating a pax Backup of OSS Files in the
Guardian File System on page 6-21.
Figure 6-4. Output of DSAP command
Subvolume Total Unused Dealloc Large Min Age Num
Name Files Pages Pages Pages File Mod,Opn Exp
...
...
ZYQ00000 2 514 5 0 472 7, 0 2
ZYQ00001 6155 485776 25411 10 34082 0,--- 1K+
ZYQ00002 1206 166448 6912 0 39082 116,--- 1K+
ZYQ00003 283 16804 851 0 4182 162,--- 283
Note. You cannot restore an OSS file that is larger than approximately 2 gigabytes to a system
running an RVU that does not include support for OSS large files.