IT Infrastructure blog

May 23, 2011

Disk Scrub in NetApp

Filed under: NetApp — Akther @ 10:46 pm
Tags: ,

Have you noticed this autosupport email from netapp box?  And there is no action required from storage admin side? quite interesting….

System Notification from FAS270 (DISK SCRUB SUMMARY – no customer action required) INFO

NetApp use disk scrubbing to protect data from media errors, or bad sectors, on a disk. Each disk in a RAID group is scanned for errors. If errors are found, they are fixed by reconstructing data from parity and rewriting the data. Without this process, a disk media error might cause a multiple disk failure while running in degraded mode.

Automatic RAID scrub is enabled by default .

You can also manually start and stop disk scrubbing regardless of the current value (on or off) of the  raid.scrub.enable option.

Degraded Mode

When there is a single-disk failure in a RAID-4 raid group or a double-disk failure in a RAIDDP raid group and there are no hot spares available, the system will operate in “degraded” mode for a period of time. The default is 24 hours. You may want to set this to a longer time interval(by using the options raid.timeout command) if access to the system is limited for a specified period, such as a long weekend.

No data is lost in degraded mode, although the system will not perform optimally. But if the failed disk is not replaced during this period, the system will shut down.

be careful about using the  options raid.timeout command to lengthen the time the system will operate in degraded mode before shutdown, because a longer interval increases the risk of a second disk failure and resulting data loss.



May 5, 2011

Useful Brocade SAN Switch Commands

Filed under: Brocade SAN Switch,NetApp — Akther @ 6:55 pm
Tags: ,

If you are managing Fiber channel storage enviornment definitly the below commands will be helpfull. I am writing in this article  few of the importent brocade switch commands for your quick referrence.

1. cfgshow   > To view all defined zone configuration information

2. fabricshow   > Can see which brocade switches are connected in to fabric

3. supportshow   > This will collect detailed diagnostic information about switch. It’s a long list command and i am putting only first part.

SANSwitch2:admin> supportshow
Wed Feb 16 06:43:42 UTC 2011

Kernel:     2.4.19
Fabric OS:  v5.0.1d
Made on:    Fri Oct 21 21:26:26 2005
Flash:     Wed Jan 11 05:05:04 2006
BootProm:   4.5.2

supportshow groups enabled:
os         enabled
exception  enabled
port       enabled
fabric     enabled
services   enabled
security   enabled
network    enabled
portlog    enabled
system     enabled
extend     disabled
filter     disabled
perfmon    disabled
ficon      disabled

time          task       event  port cmd  args
Mon Feb 14 13:58:42 2011
13:58:42.613  FSSK       event    0   16 00020000,00000000,00000000,COMP
13:58:42.759  FSSK       cmd      0   16 00000000,00000000,00000000,TAKE
13:58:43.175  FSSK       event    0   16 00000000,00000000,00000000,ACTI
13:58:43.177  FSSK       cmd      0   16 00020000,00000000,00000000,TAKE
13:58:43.344  PORT       debug   16       deadce99,00000000,000003ea,00000005
13:58:44.417  PORT       debug   16       deadce99,00000000,00000005,000003e9
13:58:44.703  PORT       debug   16       deadce99,00000000,000003e9,000003e8

4. Configshow   > This will help you to identify the configuration of a new brocade switch once implementation completed.

5. configupload   > To save the configuration file to remote host by using ftp

6. zoneshow   > To view the zone configuration ( similar to cfgshow)

7. zonehelp   > view the various zoning related commands

8. cfgenable   > To enable the zone configuration

9. cfgsave   > save zone configuration in flash

10. zonecreate   > To create a zone

11. zonedelete   > To delete a zone

12. zoneremove   > removea member from zone

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