Disaster Readiness using NIM and GLVM Maryland AIXPower Users Group Wendy McConnell June 14, 2007 Why Disaster Readiness? Traditional Backups for DR mksysb to tape mkcd or mkdvd Drawbacks of Traditional Methods Off-site transportation risks Failed Media Cost of media NIM for Backups Benefits of NIM for DR Boot from NIM Master instead of tape/DVD is more reliable Once NIM Master is restored, multiple images can be pushed at once Network load is faster than media Drawbacks of NIM Server for DR Need to recover NIM servers at hot-site Need to recover images / NIM resources from TSM Can not begin image loads until NIM is fully ready (approx 5 hours) Remote NIM Master No need to recover NIM Master image at hot-site All LPP_SOURCES needed for recovery of contracted servers Latest SPOT for each Still requires TSM AIX level required restores of mksysb NIM Master ready to images use Solution – GLVM and Remote NIM Server Global Logical Volume Manager is now included with AIX (previously part of HACMP/GEO) Allows mirroring to remote DASD via TCP/IP connection Eliminates need to recover images from NIM TSM server Both server images and TSM database backups remotely mirrored GLVM & 2 NIM Servers dr_vg /dr_images and NIM Server in /tsmbkups NIM Server at Data Center 3 copies – one at Hot Site data center and 2 at hot site GLVM Client GLVM Server hdisk rpvserver0 GLVM uses TCP/IP 1 set of LUNs 2 sets of LUNs SAN at Data SAN at Hot Center Site Caveats Must create LVs with full strictness Each mirror copy must reside on a different set of “hdisks” While active, disks on remote server should not be accessed via conventional methods – they are unavailable to AIX commands. lsdev on remote server will show “rpvserver” devices – one for each disk under the control of GLVM What DR Looks Like dr_vg /dr_images and NIM Server in /tsmbkups NIM Server at Data Center 2 copies at hot site Hot Site GLVM Server rpvserver0 – GLVM Client disabled hdisk DASD accessed as If disaster, TCP/IP hdisks link is gone 1 set of LUNs 2 sets of LUNs If exercise – TCP/IP link SAN at Data remains, and one set of SAN at Hot Center rpvservers continues Site mirroring data while other is removed from GLVM usage at “disaster date” What Happens at DR Time? If an exercise, politely remove one set of LV mirrors from the dr_vg volume group Change the rpvserver devices on the remote NIM server to a defined state. Import the dr_vg volume group on the remote nim server using the any of the hdisks that were once a rpvserver Vary on the volume group and mount filesystems – images now available What Happens at DR Time? - contd Clients to be recovered are added as NIM machine resources Images in newly mounted filesystem are made NIM mksysb resources Clients are set to perform a NIM bos_inst from mksysb Clients are booted from NIM server over network and images begin to load Benefits Have been able to shave about 5 – 7 hours from recovery time – depending on number of servers included in exercise Tapes are no longer an issue TSM backups of images are still available in the event an image is damaged All TSM database backups available via disk instead of tape – additional time savings So, What’s Required? DASD – enough on the local SAN to hold the mksysb images for the servers to be recovered at the hot site as well as any “backup software” database backups desired DASD – enough on the remote SAN for 2 copies of the mksysb images and “backup software” database backups kept on the local SAN So, What’s Required? Network Bandwidth – GLVM syncs just like LVM – so the pipe between the local and remote sites must be big enough to keep the mirrors in synch Proper tuning of time-out values for the GLVM clients depending on network flow Monitoring – whatever monitoring system in use should watch for stale partitions So, What’s Required? Servers – remote server needs to be large enough to push the number of images desired Control of mksysb image sizes – make use of the /etc/exclude.rootvg files to exclude anything that would not be useful in a DR situation (i.e. we exclude accounting software) Questions ??
Pages to are hidden for
"GLVM-NIM"Please download to view full document