Welcome Guest. Please Login or Register  


You are here: Index > Virtualizor - Virtual Server Control Panel > Suggestions > Topic : Way Faster VPS backups

2


Threaded Mode | Print  

Way Faster VPS backups
wolke
Group: NOC
Post Group: Working Member
Posts: 242
Status:
replacing the symlink to lzop can lead to master desaster!

We tested the replacement and it seemed to work perfectly but then...
We had several servers running into kernel panic after a kernel update took place and the servers had been rebooted.

The console message was:

Quote
kernel panic not syncing vfs unable to mount root fs on unknown-block"


Here is why:
When unpacking the kernel image, lzop will be used also (because of the changed symlink) but fails with several errors:

Quote
cpio - premature end of archive

Unable to decompress /boot/initramfs-3-10[....] - unknown format


and on cloudlinux server also:

Quote
Error communicating with CLN - Bad request

lzop can´t decompress several archives and thus the kernel update (exactly the initramfs generation) fails.

This happened exactly for kernel 3.10.0-962.3.2.lve1.5.25.12.el7.x86_64 on Centos7/CloudLInux

This really nasty bug has been detected by incredible CloudLinux support staff (in 3rd level support). They removed the /usr/bin/pigz symlink to lzop and initramfs generated smoothly and the server could reboot into the new kernel.
We will stay with pigz binary therefore.




Edited by wolke : July 18, 2019, 8:16 am
IP: --   

Way Faster VPS backups
domainscoza
Group: NOC
Post Group: Newbie
Posts: 13
Status:
Hi,

Thanks for the heads up on this.

@Softaculous - please can you allow us to specify the location to lzop so we don't need to do the symlink.

IP: --   

Way Faster VPS backups
wolke
Group: NOC
Post Group: Working Member
Posts: 242
Status:
There might be an even better alternative than lzop, specially when it comes to cpu time. I´am not into academic overoptimization but it seems that´s worth testing under reallife conditions.

Source: https://hannuhartikainen.fi/blog/everyday-compression-tool/

Abstract:
tool    filesize      time  CPU time
pigz      35125348    1.46    8.82
lbzip2  20301117      5.33  32.16
pixz    19333820      34.90  211.77
pzstd  39684543      0.45  2.51

IP: --   

Way Faster VPS backups
domainscoza
Group: NOC
Post Group: Newbie
Posts: 13
Status:
Quote From : wolke July 18, 2019, 10:11 am
There might be an even better alternative than lzop, specially when it comes to cpu time. I´am not into academic overoptimization but it seems that´s worth testing under reallife conditions.

Source: https://hannuhartikainen.fi/blog/everyday-compression-tool/

Abstract:
tool    filesize      time  CPU time
pigz      35125348    1.46    8.82
lbzip2  20301117      5.33  32.16
pixz    19333820      34.90  211.77
pzstd  39684543      0.45  2.51



Great find, this is really impressive:

Using Lzop:

Code
[root@node02]# time /bin/dd if=/dev/kvmvg/backup-v1002 bs=24M iflag=direct | /bin/lzop -2 > /backup/backup-v1002-lzop.tar.gz
512+0 records in
512+0 records out
12884901888 bytes (13 GB) copied, 53.2806 s, 242 MB/s

real    0m53.527s
user    0m21.149s
sys    0m28.381s


Using pzstd:

Code
[root@node02]# whereis pzstd
pzstd: /usr/bin/pzstd /usr/share/man/man1/pzstd.1.gz
[root@node02 tmp]# time /bin/dd if=/dev/kvmvg/backup-v1002 bs=24M iflag=direct | /usr/bin/pzstd -2 > /backup/backup-v1002.tar.gz
512+0 records in
512+0 records out
12884901888 bytes (13 GB) copied, 20.8995 s, 617 MB/s

real    0m23.406s
user    0m51.984s
sys    0m25.450s


Whats interesting is that the filesize with lzop is 5.1GB and with pzstd it's 3.8GB

Edited by domainscoza : July 22, 2019, 5:11 am
IP: --   

Way Faster VPS backups
wolke
Group: NOC
Post Group: Working Member
Posts: 242
Status:
Great results!
@softacoulus: please add the ability to specify the compressor/decompressor that should be used for backups so we do no longer need to do it at OS level.
IP: --   

« Previous    Next »

Threaded Mode | Print  

2


Jump To :


Users viewing this topic
1 guests, 0 users.


All times are GMT. The time now is September 20, 2019, 6:23 pm.

  Powered By AEF 1.0.8 © 2007-2008 Electron Inc.Queries: 11  |  Page Created In:0.700