Showing posts with label Backup Questions & Answers. Show all posts
Showing posts with label Backup Questions & Answers. Show all posts

Frequently asked Commvault Backup Interview Questions and Answers

Below are some of the frequently asked Commvault Backup Interview questions and Answers. Comment or submit more interview questions if you have so that we can update.

A)  It begins with monitoring the current jobs running in Job controller, Make sure that No job should be in pending & Waiting state without a valid Reason. Also check for suspended and queued Jobs. check if any of the job has got delay reasons, Also check for the Jobs which are running for more than 24 hours. Below are some of the health check tasks.
  • check for Media agent,  Tape Library(Including Tape Drives) / Disk Library status make sure that none of them are offline.
  • Check for the Free space available for Disk Libraries, Index Cache and DDB Paths (Preferable schedule a customized Report for these activites)
Daily activities
  • Extract a backup Report for Failed, Completed with Errors, completed Warnings and Killed jobs (check and act accordingly). 
  • You may check for Deployment, Decommission, Restores etc if any in ticketing tool.
Frequently asked Commvault Backup Interview Questions and Answers
2) Can you tell me about your Infrastructure ?
A) You need to briefly describe about your backup infrastructure and daily activities, for example
We have n(1) Prod commserve m(1) DR/Standy Commserve and n(10-20) pair of Media Aegents and we backup around n(2000) servers which includes Regular file system, Databases like (SQL, Oracle, Exchnage, SAP Oracle, DB2, SAP DB2 etc...). This also includes VMWare snapshot backups (VADP/VCB) / intelli snap. Include all the backups which you perform on daily basis. For Storage we have HUS 150 or HNAS with a total capacity of N(TB)

3) What are the Common/Regular backup failures ?
A) Some of the common or frequent backup issues are
  • Network Communication issue
  • Client services might be down
  • Media agent Offline
  • Destination Disk Library ful
  • Data Path offline
  • VSS snapshot backup failure
4) How to use only specific set of tapes for a server backup or for a list of server backup?
A) Create a new scratch pool and move the required media to new scratch pool and you can set at subclient which scratch pool to be used. you can also do this at storage policy, copy policy level.

5) What is difference between synthetic Full & Full Backup & Dash Full
A) Synthetic full backup consolidates all the incremental backups since last full and appends to make it a full backup. Here the server (Client machine and network utilzation is aslo very low compared to regular full ). Whereas Full backup is a complete full backup taken from server. And Dash full performs copies the unique blocks of the de-duplicated data and updates the DDB and index files to make it a full backup.

6) What is Silo (De-duplication to tape).
A) De-duplicated data is copied to tape after the primary de-duplication on Disk this is configured on global-dedup Storage policy.

7) What is Hash Algorithm
A) Hash algorithm is applied on block of data after it is read from client machine and a unique signature is generated which is used to perform De-duplication.

8) What is the default block size set for de-duplication enabled storage policies
A) 128 KB

9) What % of De-dup ratio were you able to maintain.
A) For File system backups its above 90% and Database backups 70% - 95%

10) Explain how VMware Backups works ?
A) Vmware snapshots backups are performed using Proxy server. On proxy server VSA (Virtual Server Agent) software is installed. Commvault communicates via Vcenter. Where a snapshot of VM is performed and it is mounted in Proxy server. From proxy the snapshot image is backedup to media agent.

11) What are different types of transport modes in VMware backup and their usage.
A) Transport modes is used to determine which method to be used to mount the snapshot in proxy.
Transport Mode SAN (storage area network) - SAN mode is supported for directly connected storage. The VSA should have access to the datastore LUNs that provide storage for VM disks. Data is read directly from the storage where VM resides. without going through the ESX host or transferring data over the local area network (LAN). The ESX host is contacted only to coordinate access to the LUN.
HotAdd In HotAdd mode, the Virtual Server Agent is installed on a VM residing on an ESX Server.  In HotAdd mode, the data volumes containing the VMs to be backed up are automatically mounted to the proxy, so they can be accessed by the proxy as a local disk. 
Local Area Network (NBD and NBDSSL) NBD (network block device) & NBDSSL (encrypted NBD) transmit data over the TCP/IP connection between the ESX server and the proxy computer.
NBDSSL is similar to NBD mode, but data transfer between the proxy computer and the ESX server is encrypted. 

12) How you configure a Cluster backup.
A) Create a cluster group and add the client machines in it and perform a sync, For windows during Commvault client software instaltion. It prompts for installtion on passive node(for windows). Perform installation and schedule backup.

Commvault Backup Administrator Interview Questions and Answers

Below are some of the frequently asked interview questions for Commvault backup. I have provided the answers but I also recommend to prepare your own answers for better understanding.
Commvault Interview Questions

1) What are your daily activities as a backup admin ?

2) How many backup tools do you know ?

3) What are commserve DR Procudeures ?

Hardware Fresh: Copy DR Set to Stand by commserve and perform Restore the CS DR set to satand by CS.

DR set can be restored in 2 ways.

Install Commserve software and perform restore using commserve Disaster Recovery tool GUI. And later perform Name change or

During Commserve Installtion, Perform Dr Restore from Existing backup.

4) What are the other ways of doing High availability ?
  • Clustering at SQL Level.
  • Log shipping.
  • SQL Mirroring.
5) What is a Storage Policy ?

Storage associates the client Backup to storage Disk or Tape Lib. In that copy policy is used to set Retention.

6) What is Global Dedup Storage Policy ?

The global deduplication policy enables deduplication across multiple storage policies that uses a common set of disk libraries and deduplication database (DDB).

7) What are the types of Copies and what are they ?

There can be only one Primary Copy and Different types of AUXILARY/SECONDARY. The types of copies are.

Selective Copy: A selective copy allows you to copy specific full backup jobs from a source copy, The source copy can be either a primary or a synchronous copy. Selective copy facilitates better tape rotation.

Inline copy: Here Both Primary and Secondary copy are written to storage during Backup Phase itself. Incase if the secondary storage doesn't have enough space then backup will fail.

Synchronous copy: In synchronous copy all data of primary is copied.

8) How to move the DDB to the New MediaAgent ?

Right-click the mount path, and then click Share Mount Path. point to new Media Agent. Set it to dafault mount Path. If it is a Tape Library configure tape lib and change datapath.

9) What is Inteli snap ?

It takes a snapshot, and then resumes live operations. IntelliSnap backup works in conjunction with storage arrays to provide snapshot functionality for backup.

10) What is the use of the proxy server ?

you can use a proxy server to reduce the load on the production server. The backup copy operation uses the proxy to move the snap to backup media.
  • The Storage array is accessed to create a snapshot.
  • The snapshot is mounted on the ESX server designated for the snap mount.
  • The snapshot is unmounted.
During the Backup Copy operations:
  • The snapshot is mounted to the ESX server designated for the snap mount.
  • The mounted snapshot is treated like file system and the required contents are read.
  • The file system backup is performed to Primary Copy of the storage policy.
  • When the backup copy job is finished, the snapshot is unmounted.

TSM Tape Library related Interview Questions and Answers

This is the continuation for the previous post IBM Spectrum Protect Basic Interview QuestionsIf you need to learn IBM Spectrum Protect freely visit the page Tivoli Storage Manager Tutorials. You can also find the basic Video Tutorials at Youtube channel
TSM Interview Questions

16) Common reasons for Tape Library issues ?
Check if 
  • Has the o/s changed.
  • Has the host bus adaptor Or scsi adapter connecting to the device updated or replaced.
  • Has the adapter  firmware changed
  • Has the cabling between the computer and device changed
  • Are any of the cable connections loose
  • Has the device driver changed

17) What to do if drive goes offline ?

Try to make it online using update drive command

Update drive libraryname  drivename  online=yes.

If it is not coming to online then do power cycling means power on/off.

18) How to check the actlog for hardware errors ?

      Run the follwoing command to find the hardware and tape drive errors

      q actlog se=hardware begind=-1

19)  What to u do when the drive paths are offline?

Update the drive path by using

Update path sourcename destinationname sourcetype=server destinationtype=drive library=libraryname  online=yes

20) How to define a library ?

define libray libraryname  libtype=scsi shared=yes/no  
define drive libraryname drivename

21) How to define a path for library ?

define path sourcename  destinationname sourcetype=server  destinationtype=library device=devicename

22) How to define drive ?

define drive libraryname drivename  online=yes/no

23) How to define drive path ?

define path sourcename destinationname sourcetype=server  destinationtype=drive library=libraryname device=device name

24) How to checkin tapes into library?

checkin libvol libraryname volumename  search=no/yes/bulk  status=private/scratch checklabel=yes

Yes: server searches inside the library for volumes that are to be checked in.
Bulk: server searches for the library I/o ports  that are to be checked in automatically.

25) How to checkout tapes from library ?

checkout libvol libraryname volumename  remove=yes/no/bulk.

26) How to Label a volume ?

label libvol libraryname volumename checkin=scratch labelsource=barcode  checklabel=yes/barcoede  search=yes/no/bulk

27) How to define a device class ?

define deviceclass deviceclassname  devicetype=file directory=/filedev/  maxcapacity=sizeinmb (if it is a file device class)

define deviceclass deviceclassname  devicetype=lto  libr=libraryname (if it is a Tape device class)

28) How to audit library ?

audit library libraryname checklabel=barcode/yes

If checklabel=barcode, then it will audit by using only checking barcode labels, if you specify YES, it will read the inside the label of each tape volume in order to audit the library.

29) How to Audit volume ?

audit volume volumename fix=yes/no

If you use fix=yes, then TSM will delete the data which is corrupted and if you use fix=no, TSM will only report the damaged data information but will not delete it.

30) what will u do when the library is full ?
  • First check  if all the DR volumes are checked out from the library and sent to offsite by using command

                            q drmedia  *  where state=mountable
  • Otherwise use move data command to move the data manually.
  • Start reclamation and see if it generates any scratch tapes.
  • Check out all the primary storage tapes with status=FULL to make room for  scratch tapes. 

Spectrum Protect Basic Interview Question and Answers

These are the common and frequently asked IBM Spectrum Protect (TSM) interview questions. We have tried to provide some answers for the these questions. However, please add or modify the answers as per your understandings if required. If you need to learn IBM Spectrum Protect freely visit the page Tivoli Storage Manager Tutorials. You can also find the basic Video Tutorials at Youtube channel

IBM Spectrum Protect Interview
Just as for any other interviews, Expect some basic questions about your education & work experience. Also be prepared for the questions related to your previous company and TSM infrastructure you worked upon. For example, 
  • Explain your previous company's Backup Setup ?
  • Explain how Tape Library is configured ?
  • What TDP products you worked on ?
You should be comfortable when answering the questions related to your previous experience. This will give the interviewer an idea about your dedication and interest. Once you done practice with these questions, prepare for the TSM basic concept questions. Below are some of the basic frequently asked questions and answers. 

1) What are your Daily Acivities as TSM administrator ?
  •  Health Check of all tsm servers which  includes DB, LOG, STGPOOL Utilization, and Scratch count.
  • Checking DB backup status, if it is not completed for the day then we will take Manual DB backup.
  • Troubleshooting Missed/Failed Backpus  based upon Priority.
  • Decommioning & Registering Node if any needed.
  • Checking status of admin schedules.
  • Working on new restore request if required.
  • Sending Daily status report to senior Managers on Daily Basis.
  • Co-coordinating with Onsite people related to Library & tape Issues and for any change request.
  • Installing and configuring any new TSM BAclients and TDP Clients.

2) What are the different types of TSM Licenses available ?

Tsmbasic.lic ----for basic version

Tsmee.lic-----for extended edition

Dataret.lic---for data retention version

3) How Database backup is configured in your previous organization ?

We Have a Admin Schedule Where It will take Full Backup of DB Once in a day. 


We also take DBsnapshot backup for DRM purposes.

4) How to delete DB snapshot backups which are more than 1 week old ?

We can delete by using the command

           Delete volhistory type=DBS begind=-7   

5) How to check the status of backup schedules from last 5 days ?

q event * * begind=today-5 endd=today

To get the status of only failed/missed schedules

q event * * begind=today-5 endd=today ex=yes

6) How do you troubleshoot failed/missed backup schedules ?

We need to login to client system and check the dsmerror.log or dsmsched.log if any errors reported. Then based upon those errors, we need to fix the issues and rerun the backups upon client approval.

7) How to check if TSM scheduler service status ?

           Run the below command to check the status

ps – ef  | grep -i dsmsched
ps -ef | grep -i dsmcad

            To start the services in UNIX Flavors

sudo /opt/tivoli/tsm/client/ba/bin64/dsmc sched > /dev/null 2>&1

sudo nohup dsmc schedule 2 > /dev/null &

sudo /opt/tivoli/tsm/client/ba/bin/dsmc sched -quiet &

sudo dsmc -optfile=/opt/tivoli/tsm/client/ba/bin/dsm.opt

8) What are the important Server & Client configuration files ?

dsmserv.opt, devconfig.out, volhist.out

DSMSERV.OPT: All the server configuration Information (Protocol detail, bufffersize, log pool size, Volhistpath, devconfig path)     

DEVCONFIG.OUT: All device configuration information like device class, drives                      configuration info.

VOLHIST.OUT:  All sequential volumes (LTO & FILE deviceclass) information.

         Client configuration files are

DSM.OPT----    Client settings (Windows)
DSM.SYS & DSM.OPT ----   Client settings (UNIX)
DSMSCHED.LOG----Scheduled Information will be there
DSMERR.LOG----Error related logs will be Displayed

9) What are the common backup failure problems on Windows servers
  • Server out of data storage space
  • System Object error1
  • Snap shot operation failure       
  • TCP/IP error
  • Microsoft Volume shadow copy failed
  • Authentication failure
  • Removing previous system state backup failed
  • Communication with TSM server lost
  • O.S refused memory allocation

10) What is reclamation ? How to know which tapes are eligible for reclamation ?

Reclamation is the process of moving the unexpired data from  fragmented  tapes to another tapes which are in filling tapes for the efficient use of the tape resources.  If reclaim threshold limit is set as 60%, then tapes which are having status=FULL and pct_utilization<40 are eligible for reclamation.

11) What are the TSM schedule return codes ?

0---Operation completed successfully
4---Oeration completed successfully except with one or more skipped files
8---Operation completed with one or more warning message object
12--Operation failed with one or more error messages

12) How to understand the TSM Event messages shown in activity log ?

Generally, TSM event messages are in below format

ANR [R S E] ???? [I W E S]


I Information
W Warning
S Severe
13) How to check the TSM server installation status ?

Check the following log files for the status report 


14) What is the purpose of PASSWORDACCESS GENERATE ?

Tsm client password is encrypted and stores in a file on the client. If a client receives that password
has expired from the tsm server then client generates a new password.

password dir is a option in the b/a client to specify the location of the encrypted password file
But win32 systems are having exception that the encrypted password stores in the registry

15) What are the common backup failure problems on UNIX servers

1.       File not found
2.       Directory path not found
3.       Invalid password
4.       TCP/IP issue
5.       Server out of data storage space
6.       Incremental processing on file system stopped

Latest TSM Interview Questions

  • Tell about yourself and work experience ?
  • Which ticketing tool are you using in your company ?
  • How do you assign tickets to yourself ?
  • What is Runbook  & SLA ?
  • Tell me about your TSM setup details ?
  • What are your daily activities ?
  • How do you check TSM Server health ?
  • What are the copy group parameters ? explain ?
  • How to Install & Configure BA client in AIX /Unix ?
  • What are the differences between TSM V5 and TSM V6 ?
  • What is Policy Domain & Policy Set ?
  • How many policy set and management classes can be defined ?
  • What are the default copy group parameters ?
  • Do we have to validate & activate policy set if we do any modifications to copy group parameters ?
  • What is the command to take incremental & selective backup ?
  • How to restore a file from particular date and time ?
  • How to find if a file is archived on a particular date ?
  • How do you retrieve a file from point time ?
  • What is expire inventory ?
  • What is reclamation ?
  • Difference between reclamation & collocation ?
  • How to move data ?
  • What is node decommissioning ?
  • During migration, what will you do if next storage pool is also full ?
  • What is migration ?
  • What is the difference between Backup & Archive ?
  • Difference between admin schedules & client schedules ?
  • How to check read and write errors in tape volumes ?
  • What is the difference between Physical Library & Virtual Tape Library ?
  • What is Library Manager and Library Clients ?
  • How do you check drive serial number in windows & Unix ?
  • How do you scan tape drives in OS level ?
  • How to configure storageagent/Lanfree  backup on AIX ?
  • How to configure Tape Library ?
  • Tell me the commands to checkin & checkout tape volumes ?
  • What will you do if you have no scratch volumes and no storage slots available in the library ?
  • What will you do if you need scratch tapes immediately and you have no new tapes ?
  • What will you do if TSM DB size gets full ?
  • How to increase TSM DB size on TSM V6 ?
  • What is the maximum value of Activelog ?
  • How do you increase active log size ?
  • How to check if last TSM DB backup is successful or failed ?
  • If my disk storage pool is full, what will you do ?
  • How to update migration to a disk storagepool ?
  • How do you restore oracle db backup from production system to another test system using TDP Oracle ?
  • How to configure TDP Domino, TDP SQL and TDP Oracle clients ?
  • How to link library files during TDP oracle configuration ?

Latest IBM TSM Interview Questions and Answers by IBM

IBM Tivoli Storage Manager (TSM) all rounds interview questions and answers to a one candidate. Interview took place in IBM India and it took place for more than 2 hours altogether.

TSM Interview Questions and Answers in 1st Round (by Team Leader)

1) What are your daily activities ?
Ans) TSM Server DB and Log size monitoring, client and admin schedule monitoring and library media management. I also have to install and configure TSM BA clients whenever required, and troubleshoot backup/restore issues if any. More details in TSM Daily Monitoring tasks.

2) What are first * and second * in the "Query Event * *" ?
Ans) First * is Domain name, second * is schedule name

3) How to check admin schedules status ?
Ans) Query Event * t=a

4) Where/How will you see, if errors occurred in the tapes ?
1. We can check it in actlog for hardware/media & read write errors by using command  - "q actlog se=errors"
2. To determine read/write errors for a particular volume run the command "q volume <volumename> f=d". 
This output will show the number of read/write errors occurred to that particular volume.

5) What is your DB size in your environment ?
Ans) Approximately 60 GB. 
Tip: size depends on your environment

6) What is your tape model ?
Ans) HP LTO4 tape - capacity 800 GB, speed is 120 MB/Sec.

7) Have you done DR test ?
Ans) Yes, In our environment we should do DR drills for every 6 months to ensure we are ready for any disaster recovery.

8) Have you done library configuration ?
Ans) Yess, I did it once.

9) What is your library model ?
Ans) IBM 3584 library model with 4 drives

10) Can you explain how to install and configure the tdpsql ?

11) What is the use of maximum number of mount points parameter ?
Ans) Maxnummp parameter is used to increase/decrease the client backup/restore sessions. This parameter value should not be greater than available tape drives.

12) What are the TSM server tuning parameters ?

13) What is collocation ? Where will you update it ?
Ans) Collocation is the process of keeping the client backed up data in a minimum number of tapes. Collocation can be done by nodes, node groups and by Filespace. We will update collocation while defining or updating storage pool definitions.

update stgpool <stgpoolname> colloc=node

14) What is cloptset ? Where will you update it ?
Ans) Cloptset is used to define a name for a set of options which you can assign to clients for archive, backup, restore, and retrieve operations. We should first define a clioptset name by using "define cloptset" command and then define each client options to that cloptset by using "define clientopt" command. Then you should use this cloptset name while defining any client node. Generally, cloptset is used to assign extra client options for any particular node from TSM Server end without logging into client machine.

15) Have you performed TSM DB restoration ?
Ans) Yes, 

16) How will you see the errors in the tape ?
Ans) To determine read/write errors for a particular volume run "q volume <volumename> f=d". This output will show the number of read/write errors occurred to that particular volume. Video tutorial on checking tape read write errors

17) What will you do if u find errors in the tapes ?
Ans) First we have to figure it out the source of the error, whether tape drive has caused the error or tape itself has some problems. If tape drive is the culprit make sure no other tapes are mounted on that particular tape. If tape itself has problems, then audit that tape by using "audit volume fix=no" command. This will show if there are any damaged files. IF there are no damaged files move the data from that tape to another tape, if there are any damaged files then we should restore the contents of that tape from copy storage pool.  Video tutorial on how to audit tape volume.

18) Have you done manual backup ?
Ans) Yes, We can do it by BA client command line and also through BA client GUI.

19) How will you login into the client machine do you have any credentials for you separately ?
Ans) Yes, I have client login credentials with limited privileges.

20) How many servers in your environment ?
Ans) 3 TSM Servers

21) What is the TSM library manager ?

22) On which TSM Server you will define tape drives in a shared tape library environment ?
Ans) We have to define all the drives on both Library Manager and Library clients. Configuration of TSM Library Manager

23) How will you see the lanfree backup process in the server side ? 
1. By running "storageagentname:q session"
2. Quering act log for "ANR0415I" message which says that "session  101 was proxies by storage agent S1 for node N1"
 3. You can also check the backup report for total lanfree bytes transferred.

24) How will you clean the drive ?
Ans) Generally tape library will have separate cleaning drives, we have to just mount that drive through Library GUI. OR From TSM Server we can run "clean drive" command, this will also mounts the cleaning cartridge/tape onto the drive and starts cleaning.

25) How to label the volume ?
Ans) If new tapes are kept in I/O exit port, run this below command
label libvol <libraryname> search=bulk labelsource=barcode checkin=scratch 

26) What are the parameters in the copy group ?
Ans) version exist, version deleted, retention extra, retention only, serialization, destination, mode, frequency …… etc.

27) What is the use of reclamation ?
Ans) Reclamation makes the fragmented space on volumes usable again by moving any remaining files from one volume to another volume. This action makes the original volume available for reuse. 

28) Is there any chance of moving inactive data from one volume to another using reclamation ?
Ans) No, reclamation will move both active and inactive data.

29) What is audit volume ?
Ans) Audit volume command is used to check the inconsistencies between database information and a storage pool volume.

30) What is fix=yes/no in audit volume command ?
Fix --- Specifies how the server resolves inconsistencies between the database inventory and the specified storage pool volume.
Fix=No --- Tivoli Storage Manager reports, but does not delete, database records.
Fix=Yes --- The server fixes any inconsistencies as they are detected

31) what is migration ? use of migration ?
Ans) Migration is used to move client files from one storage pool to the next storage pool in the storage hierarchy. Migration will make some empty space in disk pools which can be used for taking backup of the client machine. 

32) Have you done upgradation ? which method you have used ?
Ans) Yes, we used Same System Media Method

33) Have you done upgradation for client machine ?
Ans) Yes, First we have to copy all the important client configuration files, disconnect the connection with TSM Server and then uninstall/install new client version.

34) Have you done installation of  TSM server ? tell me the procedure ?

35) Explain the log flow in the 6.3 ?

36) What are the details available in the dsmsched.log and dsmerror.log ?
Ans) dsmsched.log  & dsmerror.log will contains the client schedule status details and any schedule error details.

37) Will the lanfree data go to the disk pool ?
Ans) No, Lanfree data will go directly to tape/tapepools. If we have a disk library in a SAN, then we can send lanfree to disks but we need another supporting softwares.

TSM Interview Questions and Answers in 2nd Round (Team Leader)

1) How to see the DB size ?
Ans) Query db f=d

2) How to check the paths ?
Ans) query path f=d

3) How to update path ?
Ans) update path sourcename destinationname srctype=server desttype=drive/library device=devicename online=yes

4) What is difference between search=yes and search=bulk in LABEL command ?
YES - Specifies that the server labels only volumes that are stored in the library
BULK - Specifies that the server searches the library entry/exit ports for usable volumes to label

5) In tdpsql what does tdpsql.cfg file contains ?
Ans) It contains all the tdpsql performance monitoring parameters like Buffers, Buffers size, sql buffers, sql buffer size, data stripes, and log file etc.

6) How to install tdpsql in the client machine ?

7) Any idea on TSM Offsite Reclamation ?

8) What is the use of storage pool backup (copy stgpools) ?
Ans) If there are any read/write errors on the primary pool volumes, we can restore them from copy pool volumes.

9) Explain how to do Lanfree configuration ?

10) Explain about policy management ?

11) What are the parameters in the copy group ?
Ans) version exist, version deleted, retention extra, retention only, serialization, destination, mode, frequency …… etc

12) Explain about Serialization ?
Ans) It specifies how Tivoli Storage Manager processes files or directories when they are modified during backup processing.

TSM Interview Questions and Answers in 3rd Round (Project Manager)

1) What is your company setup ?
Ans) We have total 4 TSM servers connected to 2 tape libraries........ etc.

2) How to do labeling ?

3) Have done up-gradation ?
Ans) Yes

4) What are your responsibilities ?

5) What is your team size ?
Ans) 3

6) What are the servers in your environment ?
Ans) AIX & Windows

7) How many clients ?
Ans) 10

8) How to find errors in the tapes ?