How to create a metasave

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Article ID: 100009600

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Description

Problem

How to create a metasave

Solution

 

This article is a part of a set on troubleshooting file system corruption. Click here to start at the beginning: https://www.veritas.com/content/support/en_US/article.100009174.html

 


Table of Contents

1. Introduction
2. Estimating time and disk space requirements
3. Creating the metasave
4. Verifying a metasave output file




1. Introduction

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Use one of the metasave scripts to create a file that contains a copy of the metadata of a volume. The metadata is a data structure that contains attributes about the data within a filesystem, but does not contain the actual data itself.

 



2. Estimating time and disk space requirements

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The metasave process reads through the metadata of a file system, seeking and examining each individual inode entry. The amount of time that is required to create a metasave depends on how quickly the system can perform I/O reads, along with the overall level of system resources available.It is possible to estimate the time and size requrements for a metasave by using the "fsadm -E" command.

More details on estimating the time and disk space requirements for collecting a metasave:

"How to estimate time and disk space requirements for collecting a metasave"
https://www.veritas.com/content/support/en_US/article.100016698.html


 

3. Creating the metasave

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Dismount the volume and then create a metasave (Figure 1). The metasave collects the file system metadata, which is the portion of a filesystem that contains the attributes of the data, but does not contain the actual data itself.

Note: This step requires the filesystem to be unmounted.



Figure 1 - Creating a metasave

Syntax:

/opt/VRTSspt/FS/MetaSave/metasave_ -f /dev/vx/rdsk//
 
Note: Replace "" with the correct platform. Several metasave scripts exists, each corresponding to a different platform.


 
Example, with typical output:

# umount /vol1
# /opt/VRTSspt/FS/MetaSave/metasave_rhel6_x86_64 -f /var/tmp/metasave.out /dev/vx/rdsk/datadg/vol1
#
 

 




4. Verifying the metasave output file

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To verify a metasave output file, use the same metasave script that was used to create the file.


Figure 2 - Verifying a metasave


Syntax:

/opt/VRTSspt/FS/MetaSave/metasave_ -i
 
Note: Replace "" with the correct platform. Several metasave scripts exists, each corresponding to a different platform.


 
Example, with typical output:

 #./metasave_10 -i /var/tmp/metasave.out

METASAVE image header:
magic 0x56784d53  version 6  fsblks 2150400  fsbsize 1024

Original VxFS super-block contents:
magic a501fcf5  version 7  ctime Tue Sep 16 07:03:55 2008
logstart 0  logend 0
bsize  1024 size  2150400 dsize  2150400  ninode 0  nau 0
defiextsize 0  ilbsize 0  immedlen 96  ndaddr 10
aufirst 0  emap 0  imap 0  iextop 0  istart 0
bstart 0  femap 0  fimap 0  fiextop 0  fistart 0  fbstart 0
nindir 2048  aulen 32768  auimlen 0  auemlen 8
auilen 0  aupad 0  aublocks 32768  maxtier 15
inopb 4  inopau 0  ndiripau 0  iaddrlen 8   bshift 10
inoshift 2  bmask fffffc00  boffmask 3ff  checksum edd6485f
oltext1 32  oltext2 18178  oltsize 1  checksum2 0
free 1948627  ifree 0
efree  103 48 131 8 8 4 5 3 1 0 1 0 1 1 0 1
#
 

 

 

 

 

Issue/Introduction

How to create a metasave
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