How many tpaes does it take to do a GFS?
This GFS Strategy is bugging me as there is no defintive answer to how many tapes to buy. So how many does it take to get to the center of a tootsie pop? So many different numbers for a GFS Routine it is nuts. I have read anywhere from 12 to 19 and neither adds up. Considering that GFS has been around since my Grandfather, one would think someone would have a number of tapes. Now I have to convince my supervisor that hey we need X=Number of LTO-4 Tapes * 2 at the cost of $30.00 a cartridge. The rub is you can't overwrite tapes each day or you don't have a backup to go back to. So what do you tell your supervisor?
O.K. when it comes to backup's I am a belt and suspenders type of guy. Screw incremental and the partials. I want a full backup of my users data every night. Here is my GFS rotation
Monday - Thursday = Son = 4 tapes. I would like to keep the Son a full daily set until the Father is run on Friday = 1 x rotating back after 26 days days. On the 1st Saturday of the month I run Grandpa and want to keep these tapes for a year. 12 tapes. Sunday I run other maintenance programs, do scans and on the 7th day the tape backup rests. My library can hold 28 tapes plus a cleaning tape. I know 29 is an odd number but add a mail slot and you get 30.
In order to do a complete backup of user data takes 2 LTO-4 tapes. So mmultiply by 2. It would be favorable to have an extra 4 daily tapes so 4 tapes don't get run into the ground.
So I need 24 tapes for the Granfather = rotate out every month to keep off-site. 8 Tapes for the Father 6 can't be touched for 4 weeks and 8 tapes for the son. But these tapes can't be touched for 5 days. So I have to rotate in 2 new tapes for the grandfatehr each month. My library holds 31 tapes. So I would have 8 tapes tied up for 6 days, 14 tapes tied up for 28 days which = 20 tapes in limbo givining me 11 tapes to have on ready for each full backup and to keep any tapes from over use. Golly I hope we don't nee to have 3 tape backups.
Bear in mind I want full backups for as long as I can get my users data backed up. I am open to any suggetions, changes - except full backups, ideas or a better way. Although, we already bought into this system so don't tantilize me with SANS and constatnt backup.
Thank you,
O.K. when it comes to backup's I am a belt and suspenders type of guy. Screw incremental and the partials. I want a full backup of my users data every night. Here is my GFS rotation
Monday - Thursday = Son = 4 tapes. I would like to keep the Son a full daily set until the Father is run on Friday = 1 x rotating back after 26 days days. On the 1st Saturday of the month I run Grandpa and want to keep these tapes for a year. 12 tapes. Sunday I run other maintenance programs, do scans and on the 7th day the tape backup rests. My library can hold 28 tapes plus a cleaning tape. I know 29 is an odd number but add a mail slot and you get 30.
In order to do a complete backup of user data takes 2 LTO-4 tapes. So mmultiply by 2. It would be favorable to have an extra 4 daily tapes so 4 tapes don't get run into the ground.
So I need 24 tapes for the Granfather = rotate out every month to keep off-site. 8 Tapes for the Father 6 can't be touched for 4 weeks and 8 tapes for the son. But these tapes can't be touched for 5 days. So I have to rotate in 2 new tapes for the grandfatehr each month. My library holds 31 tapes. So I would have 8 tapes tied up for 6 days, 14 tapes tied up for 28 days which = 20 tapes in limbo givining me 11 tapes to have on ready for each full backup and to keep any tapes from over use. Golly I hope we don't nee to have 3 tape backups.
Bear in mind I want full backups for as long as I can get my users data backed up. I am open to any suggetions, changes - except full backups, ideas or a better way. Although, we already bought into this system so don't tantilize me with SANS and constatnt backup.
Thank you,
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ASKER
I really appreciate all the comments. The D2D2T with De duplication is the way to go but I am stuck with what I have at present. All I backup are my user files and a few choice files from DHCP and SQL.
I have found backing up the OS is, how the French say, "a waste of time". One item is some OS files will not be backed up and the other is, I load the OS just to get my drivers for the tape drive and library. I have seen the bare bones approach but if i don't have all the OS files I am screwed.
I have a nice library with an HP LTO 4 drive using Bar Codes. With Symantec Backup Exec 12.5, soon to be 2010. I run a SATA RAID 5 with a 256 stripe so that is my backup. Then I have a SATA RAID 1 for my OS.
I prefer the nightly full backup and rotating monthly off site and weekly to a fire safe on site. The LTO-4 runs fast enough to allow this to happen. I don't run a Sunday backup due to othe automated maintence functions. Using the diferential is OK but if I can get the full back up what the hey.
Still trying to nail down the number of tapes is a pain. So far I have come up with 48 as a minimum. We have a lot of GIS files which doesn't compress so that takes 1 tape.
See next comment:
I have found backing up the OS is, how the French say, "a waste of time". One item is some OS files will not be backed up and the other is, I load the OS just to get my drivers for the tape drive and library. I have seen the bare bones approach but if i don't have all the OS files I am screwed.
I have a nice library with an HP LTO 4 drive using Bar Codes. With Symantec Backup Exec 12.5, soon to be 2010. I run a SATA RAID 5 with a 256 stripe so that is my backup. Then I have a SATA RAID 1 for my OS.
I prefer the nightly full backup and rotating monthly off site and weekly to a fire safe on site. The LTO-4 runs fast enough to allow this to happen. I don't run a Sunday backup due to othe automated maintence functions. Using the diferential is OK but if I can get the full back up what the hey.
Still trying to nail down the number of tapes is a pain. So far I have come up with 48 as a minimum. We have a lot of GIS files which doesn't compress so that takes 1 tape.
See next comment:
ASKER
Who makes archival DVD's? I would save the key to at least 4 places on and off site.
Loved the change for a $100.00 dollar bill!
Loved the change for a $100.00 dollar bill!
ASKER
BigSchmuh:
Part of my pain is setting the over write period. If I set my 12 dailys to 6 days. My weekly rotate out to 28 days and my monthly to 365 days.
So your basing a 10 month rotation over the 12. My library can handle 28 tapes so keeping FB's for a week and rotaing out the Saturday set would work.
After 6 days I would always have 2 tapes available but I should keep 12 days of weekly in the library. 24 Tapes. Then have another 24 tapes for my monthly off site. Now I have 48 tapes putting in 2 new tapes each month. I would then have 8 weekly tapes that are rotated to the fire safe for 28 days. Which is 16 tapes so I really need 64 tapes to maintain the over write periods. Rotating in 2 new tapes or I will hit lock down on my backup is 3 months?
Everything is SCSI 320 on the backup. The RAID 5 is SATA with a big stripe. It is all local so no bandwidth issues. No money for tapes so D2D2T is a pipe dream for this IT Department.
Part of my pain is setting the over write period. If I set my 12 dailys to 6 days. My weekly rotate out to 28 days and my monthly to 365 days.
So your basing a 10 month rotation over the 12. My library can handle 28 tapes so keeping FB's for a week and rotaing out the Saturday set would work.
After 6 days I would always have 2 tapes available but I should keep 12 days of weekly in the library. 24 Tapes. Then have another 24 tapes for my monthly off site. Now I have 48 tapes putting in 2 new tapes each month. I would then have 8 weekly tapes that are rotated to the fire safe for 28 days. Which is 16 tapes so I really need 64 tapes to maintain the over write periods. Rotating in 2 new tapes or I will hit lock down on my backup is 3 months?
Everything is SCSI 320 on the backup. The RAID 5 is SATA with a big stripe. It is all local so no bandwidth issues. No money for tapes so D2D2T is a pipe dream for this IT Department.
I am not sure of your rewriting of my suggestion...
I suggested to (1 + 2b above) :
-Have 6 days of full compressed backup + 1 uncompressed backup on disc
==> No tape + (7x1.5TB=) 11TB backup disc space (8x2TB for 12TB in RAID6)
-Have a weekly (2 tapes) backup (from the daily disc one) that is stored offsite
==> (2-tapes x 20 = 40 tapes offsite with 10 month + 10 weeks for a full year) + 2 tapes ready to handle the next set + 2 tapes (spare or to-be-offsite-soon) = 44 tapes grand total
Once a week, you :
-put in the spare set for it to be ready for next week tape backup and take your new set of 2-tapes offsite
-get back with the weekly-or-monthly obsolete 2-tapes that becomes your new spare set onsite
==> To reduce this 44 tapes to 34 tapes, you can lower the weekly sets to 4 weeks and add a monthly one (Monthly covers 2 to 12 months backward)
==> To reduce this 44 tapes to 30 tapes, you can lower the weekly sets to 4 weeks, add a monthly one and remove 1 on 2 monthly older than 7 months (Monthly tapes would cover 2 to 7 months backward and 9-11-13 or 8-10-12 alternatively)
I suggested to (1 + 2b above) :
-Have 6 days of full compressed backup + 1 uncompressed backup on disc
==> No tape + (7x1.5TB=) 11TB backup disc space (8x2TB for 12TB in RAID6)
-Have a weekly (2 tapes) backup (from the daily disc one) that is stored offsite
==> (2-tapes x 20 = 40 tapes offsite with 10 month + 10 weeks for a full year) + 2 tapes ready to handle the next set + 2 tapes (spare or to-be-offsite-soon) = 44 tapes grand total
Once a week, you :
-put in the spare set for it to be ready for next week tape backup and take your new set of 2-tapes offsite
-get back with the weekly-or-monthly obsolete 2-tapes that becomes your new spare set onsite
==> To reduce this 44 tapes to 34 tapes, you can lower the weekly sets to 4 weeks and add a monthly one (Monthly covers 2 to 12 months backward)
==> To reduce this 44 tapes to 30 tapes, you can lower the weekly sets to 4 weeks, add a monthly one and remove 1 on 2 monthly older than 7 months (Monthly tapes would cover 2 to 7 months backward and 9-11-13 or 8-10-12 alternatively)
ASKER
Well it was more for me to think it through. I don't have the disk space to do an uncompressed backup to disk. My other issues is my GIS info is already compressed so I get 1:1 ratio on it. That is about 800 GB's so doing HW compression, which I do, doesn't do squat for that info.
I am rereading your post to see how I can get it to work. I am not sure of any legal obligation I have to maintain a 12 month of backups. Sure don't want to tell the big boss in a litigation issue "What files from when" of course that could go either way.
I am rereading your post to see how I can get it to work. I am not sure of any legal obligation I have to maintain a 12 month of backups. Sure don't want to tell the big boss in a litigation issue "What files from when" of course that could go either way.
ASKER
D2D with deduplication is the way to go. For now it is the tape library. The good thing is i can easily store tapes off site. Doing a D2D over the WAN on the weekend might work.
But the realy bad thing is, that it looks like there is no attention whatsoever for restore times. Which is what all backup is for, right?
Given the fact that most restores are file restore for files that were created (and got lost) in the last 48 hours, incremental backups or differential backups compris only a small amount of tape. The recovery of data form a recently changed file from a tape with only a few percentage of the tape occupied will deliver a much faster recovery period.
I hope you backup and recovery objectives do not tell you, that recovery of lost data must be fast, otherwise your full backup point of view may work against you in case of real (CEO driven) emergency...
BTW D2D2T backup will also present you a much tighter maze of unrecoverability, since you will perform backup maybe each hour in stead of each day. What if your important data, that was created only 30 minutes after your last backup was destroyed two hours ago?
A simple iSCSI box for the price of a set of LTO tapes must be worthe it, considering the fact that you will then only need a fraction of the amount of tape for off-site tape backup!
Tell you boss you have change for a 100 dollar bill, but only in notes larger than 90 dollar!